Thank you very much for the very helpful method. I have a 12V 12Ah battery which died and it didn't react on smart battery charger. Using your method I was able to recover the battery and use it. As I don't own lab equipment, 1st I have used 36V 4.5A adapter, the current was slowly rising from 0.01A to above 2 A over a day and battery gets very warm, batt. voltage at the end of the day was above 10V, which dropped to 8V overnight. So I started the cycle again next day. until the current rose to 3A, I stopped there as I don't own lab equipment, voltage at the end of the day was above 11V and dropped above 9V overnight. Next day I took laptop power supply 20V 4,5A and it took approx a day the current rose above 2A and batt. voltage was above 12V. Then I attached the smart charger, and it charged the battery overnight. I took few days but I can use it now.
That's great! I much enjoy situations where people use what they have on hand to accomplish things that ordinarily wouldn't be possible without some knowledgeable creativity. Sometimes the best hammer you have on hand is a wrench, and sometimes the best pry bar you have on hand is a screwdriver. It works.
I'm glad to see you back. I find your videos very informative, accurate, and helpful. Production quality is not as important as the three things I just mentioned. Whenever you need a break or don't feel like doing videos, that's your prerogative.
Hi, excellent explanation. I hope you will also be doing switching power supply , chargers and inverter type repair videos like all the ones you did before. I very much enjoy your videos, thank you for the considerable time and effort that you must put into producing these videos for all of us that really enjoy watching them. I hope that the coming here will be very good and rewarding for you.
Hi , thanks for the video. you look expert on the topic, and all the reasonings sound correct. Do you have any link or literature on this? I would like to have more details on how much current should I set for a 100Ah battery, with several hour process. what is the dependance with temp and so on (I'm desulfating my camper batt)
Thanks for this. I have a 12v 20Ah SLA battery that I neglected and when I tested it, it was 6v. None of my smart chargers would touch it. I have a lab power supply and it never dawned on me to try that - even though I've used it before to charge batteries. Anyway, 24hrs later and it was taking 2Ah from the power supply. It's now charging on a normal charger which shows 20% charge. Even if it's not useful at the end of the exercise, it was fun!
the reason "smart" chargers don't touch dead batteries is because they don't see a load and they have short circuit protection built in because dumb people like to shock themselves or start fires. you can trick them into seeing a load by putting a high-wattage resistor or incandescent light bulb in parallel w the battery.
Nice to see you back too! I loved the inverter reviews. I have learned that nearly all batteries that came from computer UPS's are usually toasted. I think they are just boiled dry. I have found a few bloated out too. The only batteries that stand a chance of recovery are ones that were simply neglected, under charged, sat on a shelf for 2+ years since new. There is no way of recovering a battery that has been cycled over and over to near dead everytime, or float charged at 15 volts like some UPS's can do. They're just pooped out.
I agree. Most UPS units are designed for battery changes every couple of years and they 'boil' them dry fairly quickly by floating them at a high enough voltage to recharge them relatively quickly after use but low enough to avoid the cost of a multi stage charger. The old ubiquitous APC Smart UPS units float them at around 14V from what I've seen.
All batteries can dry out which is a point that all battery manufacturers are aware of but never disclose to their customers. So when they say Gel and AGM are maintenance free, it's like saying transmission fluid is 'lifetime' fluid...yeah, for the lifetime of the vehicle which is a relative term. I think there needs to be more testing done by flooding AGM and Gel batteries to see how many if any are recoverable by adding water. AGM should have the best luck as I spoke with one manufacturer that told me they flood their AGM batteries with a typical water and sulfuric acid solution then dump out the excess in order for the battery to be classified as "AGM".
Knurlgnar rulz! Fantastic to enjoy regular content from you again - please don't burn out, you have lots of fans out here who understand if you need a break - just keep on creatin' !
Yah a new video Great to see you back 👍 I'm interested, just bought home a dozen of these from ups's that I picked up for a test run of my solar setup while I build the 18650 packs Look forward to part 2 And hope you make more, I've watched All you back catalogue
Can't believe you made it through all of my boring monologues! I fear my love of lead acid batteries may become obsolete in time as lithium batteries get less expensive. :( I do expect insurance companies to ban lithium battery banks in houses in the near future though unless very onerous and expensive 'certified and inspected' government approved pre-built units are used. Unfortunately the law will likely blanket all types of batteries because government is lazy. Thanks lithium! ...
@@knurlgnar24 Haha, I thoroughly enjoyed them, a good mix of detailed infomation with your impressions thrown in, not long and boring but also not just edited highlights I only came across you a few years back when I started getting some free laptop batteries, so it was your inverter tests that attracted me Think I ended watching everything you'd published, so great to see new content Agree with your thoughts on lead acids future, they've served us very well with little change over the years and are definitely far safer than lithium Appreciate your reply, take care and wish you all the best
@@knurlgnar24 The 2017 National Electric Code has a new section 480.3 which reads as follows: "Storage batteries and battery management equipment shall be listed. This requirement shall not apply to lead-acid batteries." Based on this, I would expect insurance companies to ban homemade lithium banks, but allow lead-acid. At the very least lead acid banks will almost assuredly remain legal. I really don't know what sore of wording insurance companies would use to ban lithium banks, maybe capacity would be a factor.
I was interested in the desulfation process. I wanted to look it up because I have a 7-stage charger and was wondering what is the Battery Desulphation mode is. And then, about 09:43 you are openening up some Dragons Milk! Oh wow haha! Nice, I had that before.
Gel batteries are very sensitive to outgassing so I'd guess the battery would be ruined if kept at 15V for an extended period of time. So long as the maximum charge specs for the battery are followed to avoid permanent gas pockets in the gelled electrolyte you'd be OK and the process should work - it would just take a long time since you're limited in how much current you can force through a gelled battery.
So I'm guessing that the bubbling is the conversion from Lead Sulfate back to Sulfuric Acid. At first it was chamber 1 (closest to the negative) and chamber 6 (closest to the positive) that would bubble but after several hours chamber 1 won't bubble at all. Is it chamber 1 finished desulfating or is it dead?
I am using a 12v/10a charger that has a brief 12v/50a engine start mode. I just keep switching between the 2. It's just interesting because at first only chamber 1 would bubble. Now it's the only one that doesn't.
I am attempting to recover a Absolyte 48 volt, 2000 amp hour battery... I am trying to learn this process. Is it possible to remove each 2 volt cell and independently charge each cell to a state of charge? I am hoping to achieve as many cycles as I am able. Am I out of my mind for even attempting?
I have a U1 12V battery that sat for at least 4 years from my snowblower. I didn't bother maintaining it since I have had a snow clearing service. Anyway, it has been stored indoors just to make sure it didn't freeze. It read just over 6V and I decided to charge it with my new Pro-Logix PL2320 (at 2A)...I had to see if it worked. (all my other chargers are low current chargers/maintainers). Incredible, it took a charge and then went into maintenance mode. I did a load test at 100A and it dropped to 10V which it held. OCV a day later is 12.60V. I have done a few charge and load test cycles. So far so good.
great video. i was trying this on a similar battery to yours. I had the power supply at 32v and it reached 1.3A then the current suddenly tanked all the way down to 200ma. Battery didnt seem that hot. Any explanation for this?
i'll try this with my nackered old sealed acid batteries , they hold only a tiny charge and i do have an old charger and big 12v motor to discharge it , was thinking getting 2v cells from a forklift and trying those on my solar setup to get free power at night but here in scotland hard to find tham. thanks for posting
i have two batteries a car 12v/40AH flooded type & a bike 12V 5AH maintenance free both cannot start the engines but do show the voltages, even get charged, can i fully recover them.
It depends on their history, but unless they sat unused for long periods of time their problems are likely not sulfation. Your batteries may have simply reached their end of life and need replacing with a new battery. Motorcycle batteries in particular tend to have short lives as they usually use higher acid concentrations to boost performance at the trade-off of useful life.
Probably not unless the battery is only low on CCA due to sulfation. The most likely scenario is that the battery is simply old and needs replacing soon. Then again 550CCA should be plenty for most any vehicle even during the winter.
Great video, I will have to try this method on a couple batteries I have kicking around, worth a shot, but I wonder if the old timey unfiltered DC (pulsating) charger would have a better chance at desulfating?
@Thomas Chrombly But some of the newer "smart" chargers won't work if the battery is dead. The old "dumb" chargers which are nothing more than a trasnformer and rectifier will try to charge anything connected to it.
@@MRCNC1967 I have found that attaching a smart charger AND an extra voltage source will trick the smart charge to begin charging. Once it sees a base voltage, then remove the alternate voltage source and let the smart charger continue to charge. JwgK
Hay. I have no problem getting two car size lead flooded battery to a rest voltage of 12.4, 12.5 volts. The problem I have is when I hook up the battery to any load like 65W headlight. The voltage drops to below 12v immediately and I get at most get a few minutes before it get below 11 volts. Cycling does seem improve it. Are my batteries toast at this point?
If overcharging them and cycling them while keeping electrolyte levels topped off doesn't improve them then your batteries are likely 'toast'. They do have a finite life unfortunately. Sulfation is one of the most common abuses they suffer and THAT can be recovered. Worn out batteries that have lived a good life and have no more to give just have to be replaced.
@@knurlgnar24 These are fairly new batteries less than 5 years old. In my case here being able to get the rest voltage to 12.5v or above but with no capacity. You think overcharging it more would help. Because I stop over charging (switch to a smart charge) once I get the rest voltage to 12.5v.
Very good video, please answer me I have the following problem, my laboratory power supply unit Wantpek APS3010H unfortunately only charges with CC until it reaches the closing voltage and then with CV and then the current drops, how did you set it so that you charge with CV and the current rises, thank you
Your power supply is working properly from what I can surmise from your comment. The current limit and the voltage limit are independent. If the voltage limit is reached current is lowered to prevent voltage from going higher, and if the current limit is reached voltage is lowered to prevent the current from going higher. It sounds to me that your batteries are not severely sulfated and are charging like typical batteries instead of charging like damaged batteries as shown in this video.
Hii very nice information, but i have question I use the gell battery when it is full 13.2 volts and get a load of 2a baterai drops 11 volts, how to fix it sir? Thanks
It depends on the battery. If it is a smaller battery that may be normal simply due to charge mobility and internal resistance, but if it is a larger battery, say 20Ah or larger then that isn't normal. Gel batteries are more difficult to restore as any 'bubbles' are permanent and damaging. To desulfate a gel battery you would need a very mild overcharge for a long period of time.
@@knurlgnar24 thank you for answering the battery that I use is 12 volt 100a, when I charge it with 14.2 for a few seconds it is immediately full with a voltage of 13.2 volts. for 2 days the voltage is still 13.2 volts but when given a load of 2a it immediately drops to 12 volts, and then the load is released voltage back to 13 volts again, is this due to sulfation or maybe the cell dry? I've used the method you used to recover battery before and it worked very well thank you for your information sir
Thanks for the comment! So many useful batteries are destroyed every year which could be used instead to reduce waste, increase overall wealth, and help the environment.
knurlgnar's hands are back from hiatus now too! :D fun fact, Evervolt's old school 9 volt batteries used to have a black and white cat in their logo not unlike yours! so i'd say that's very appropriate! enjoyed the video and looking forward to how it turns out in part 2
@knurlgnar24 oh ok, Its hard to see as it's only one cell and barely swollen. I checked it yesterday after 24 hours of charging on a laptop charger using a light bulb to bring it down to 12v, it actually held a charge for once and lasted about 2 minutes under load before dropping to 11volts.
I watched part 2 and then came back to view part 1.....still good info. I have removed the cover and rubber caps ( valves ) to add distilled water with a syringe into the cells. Is there a way to check specific gravity so that I may mix acid and water to be close to original solution ? I did not know before about leaving some headroom over the plates for off-gassing to re-constitute. Thanks JwgK
Hi, I been try this process on a battery of and on for the last few months and I think I gotten some improvement. The Battery is fairly new. And I have gotten a totally dead battery to have a standing voltage of 12.9 volts if it is fully charged. However the capacity reads 200-300 amps on a load tester and the battery is a 900 amp battery. It look like I have a very weak cell next to the negative terminal. When I look into the cell I see definitely sulfaction on the plates and I read very low SG on the cell, and I don't see any bubbles. So it look like I have 5 super strong cells and a near dead cell. So if I can fix this cell I am there. So should I try to keep cycling the battery more a hope to revised the last cell? Should I try Epson cell on the last cell? Should I try to flush and fill the last cell? And I heard I can remove some of the acid solution from this cell and replace it with distill water and keep cycling it and that would help??? thank you
I don't support adding any foreign agents into a lead acid battery as I see no evidence that it actually is effective overall considering all variables, but if you want to try it it's your property and I'm not offended. That cell is likely the primary sulfated cell and it's possible its just too far gone. You can always try to continue the overcharge and cycle approach but it doesn't work for all batteries. Sulfation causes non-reversible damage unfortunately. You clearly reversed a good portion of it already. The industrial approach would be to empty the single bad cell, wash, refill with distilled water, charge the single bad cell to remove sulfation, then refill with acid and charge that single cell to reform. Then rebalance all cells. I doubt that's practical for your battery.
When you are desulfating, to get the best result quicker are you supposed to be charging the battery at the same time its being desulfated? or do you want the processes separate? Thank you.
The charging step is what does the desulfating. Cycling the battery primarily does two basic things: 1: It allows you to judge your progress. 2: It physically stresses the plates causing shedding which exposes new active lead to the charging process, and helps to create stress cracks which allow conversion of additional sulfate into useful active material. Shedding isn't desirable but is an inevitable part of the process.
I have an issue I can't find a solution for. I have an alarm in my vehicle. Having been out of work since 18OCT2020 I don't have a need to drive each day. So my battery has 12V but seems to have no current. It will not take a charge. Even using the 55A Starting circuit it will no even turn the motor. What would you recommend. Are there solar chargers that I could put on it to keep it up with the alarm pull?
I'd disconnect the alarm and force charge the battery for an extended period of time. Lead Calcium batteries (which are the standard for North America) refuse to accept a charge after complete discharge for a time until they slowly start accepting charge again. After that point you will still need to desulfate the battery.
you should call your self a professor. question i have a flooded battery i measure each cell with multi meter and only one cell give me -0.3 v instead of 2 volt. can i recondition that cell assume i do all safety procedure by put negative terminal of lab power supply on that cell and positive terminal in the main positive terminal of the battery? thank you a lot.
If you have access to each individual cell you can desulfate each cell separately. It sounds like you have a single cell inversion where the cell reformed in reverse polarity. This is pretty common and somewhat difficult to rectify unless one has access to the inverted cell. With lead calcium batteries in particular this is quite common as manufacturers add dopants to the 'good' cells to cause them to leak current as much as the 'worser' cells so that the user doesn't end up with the problem you have. Chemistries with higher intrinsic leakage currents don't need this dopant which only makes good cells worse. This disrupts the battery chemistry as they age and leakage rates change though - cost cutting right? Anyway, I'd suggest desulfating just that one cell first if you are able to access it. Be sure to keep the water to the proper level at all times. Wish you the best.
What is the recommended discharge current to optimally recondition a battery? Isn't it that there is some trade off between the long reconditioning time, amount of water evaporated, and the level of the good sulfur coming back to the electrochemical reactions? Please explain this part more.
Attempting to desulfate a marine battery. Charged voltage at 13.5 volts but has no cranking amps so I am assuming it's badly sulfated. I bought a power supply and I'm pumping 16 volts 8 amps DC and the electrolyte is bubbling occasionally and as time goes on the amps are dropping, is this normal?
My friend has a solar setup and we are wondering; do we have to disconnect each battery to desulphate or can it be done in situ? A very informative video, thanks
The general answer is that they should be disconnected from the system to desulphate but there are exceptions. If you have them in parallel then disconnecting is required in all cases. If you have, for example, a 48V system with 4 batteries in series then you don't have to disconnect them if you're careful. On that hypothetical 48V system one could choose to idle the battery bank at 100% SOC and then desulphate just one of the 4 batteries in the 4S configuration, but the bank has to be either disconnected from the load/charger or idling at float and 100% SOC. Short answer is that batteries should be desulfated alone, disconnected from the battery bank. If for no other reason than they are going to outgass a lot and get hot, and it's probably better to do that in a safer location.
Thanks for pointing me to this video. The batteries I mentioned in my last message all test at around 12.5+ volts. I'm glad they are totally run down. Coincidentally the 20 batteries I have are from the same company they are leoch lpc12-75
I remember your comment but can't seem to find it - youTube mysteriously deletes things at will for unstated reasons. In any case those sound like very nice batteries and I hope you are able to restore them to useful condition and make use of them! I'd take those for my battery bank if I had the chance. :)
@@knurlgnar24 Ah, ok, thanks for that clarification. I suppose the importance of what you are demonstrating here is the higher voltage but only a few amps. Is this lab power supply then also sufficient for charging a regular car battery?
I wouldn't recommend using a welder as a battery charger. They aren't intended for that and have a high inductance output which is dangerous for battery applications. (but good for welding)
@@knurlgnar24 THANKS-- i did see this method however....... dialed in to around 30A input: speeds up force restore/desulf. Thoughts? ua-cam.com/video/VYtkn-N_p4s/v-deo.html
Would this work on my weak 6 year old AGM car battery? The car has start/stop with energy recuperation technology BS . Or is my battery just worn out? The car apparently only charges the battery to 80% so I’m wondering has it caused sulfation. Maybe the smart charging prevents that?
If you regularly drive your car and it hasn't been sitting unused or only driven a couple times per week I expect you simply need a new battery as they have a finite lifespan. 6 years is pretty good for a vehicle with start/stop. That's hard on a battery.
@@knurlgnar24 thanks for reply. Yeah the car does 600 miles a week. I also think it might have a high self discharge rate problem. I had interesting readings from the battery monitor when it was left sitting at the airport for a week.
I have 6 8ah 6v lead acid batteries. They are 6 years old and have never been used. The voltage dropped to around 0.5v each. I tried CC at 1a for an hour on each battery and all of them immediately dropped to 2-3v when I took off the charger. Is there anything else I can try before throwing them out?
I have a couple of videos on recovering sulfated batteries. They may be worth checking out. If your batteries are old and never used it is highly likely that you will be able to recover them to a condition that is slightly less than perfect but very usable.
@@knurlgnar24 I have seen them, they were definitely helpful. Over the last couple years your videos have saved me hundreds of dollars of batteries. Unfortunately it seems at least 4 of the 6 batteries have internally shorted in at least one cell. I just had one of them swell up like a balloon while I wasn't watching, lol. I guess I've tried everything at this point. The charging the voltage would slowly drop from 35v down to around 10v at 1a. The battery would stay just barely warm and then the voltage would drop to around 3v and the battery would get super hot in less than 20 seconds. This happed for 4 of the 6. Is there something I'm doing wrong or are these batteries just toast?
I have 2 of same battery with low capacity problems . Can i use my 28 volts printer adapter rated at 2 amps maximum to try reconditionning them ? As battery prices in lebanon are getting very expensive . Tnank you for the informations
Those adapters have a hiccup overcurrent protection mode, so you would have to add resistance between the battery and adapter to limit current to less than 2A. Be careful and be safe if you decide to try it!
just saw you have a ton of amazingly helpful off grid vids... thanks muchly... any hope for my crown 420ah l16s(2 in series at 12v) that drop down to 12.6 volts after sundown due to my ignorance in having had an under powered pv setup when i got them? they got drained down to 11.7v almost every night for the first month i used them and never got fully recharged during the day. so now if i disconnect the charger they slowly drop down from @13.9 to 12.6 over a cpl hours with no load. they will mabey loose another .1v overnight if i have no load but if i run them down to 12.2v they are still at 12.2 in the morning. i feel like they are good candidates for salvation compared to what you used for demos. can this be over a period of days on and off? any help not ha having to replace this wasted 600 dollar battery bank would be greatly appreciated. thanks.
I can pretty much guarantee that you can restore those batteries to near 100% without much trouble. If it's only been a few months of damage due to undercharging it will be almost completely reversible. I'd need a specific model number to give specific advice, but whether these are AGM, flooded lead antimony, flooded lead calcium, or pure lead makes a difference in the details. (I will assume flooded of some chemistry) The short of it is I would recommend disconnecting or turning off the solar and inverters and doing an extra long equalization charge. Crown likely recommends something like 5 hours for maintenance purposes but since yours are damaged they will need more than that - maybe a full day. Keep an eye on temperatures and electrolyte level during this time. If you have a hydrometer keep charging until sg stops rising in all cells. After that do a deep discharge, log the result, and do a normal full recharge followed by the crown recommended equalization charge. Repeat. Once your capacity result during the discharge tests stops rising you are done and given your situation it will probably take only 1 or 2 cycles. Obviously the most important thing is to not let them get damaged in the first place but life isn't ideal and these things happen - fortunately it's not a big deal as long as the situation is rectified in a reasonable amount of time.
@@knurlgnar24 thanks so much .... I am completely off grid so I can't charge them externally I can set my charge controllers To equalization voltage for a few hours at a time a few days per week...will this eventually do it? If not since I am switching to Chinese prismatic 3.2v x16 for 48v sometime this winter and run an external charger then. (BTW they are a pair of crown CR-430 6v in series.) and these big fla are to expensive and too heavy to junk... Awesome info ...hope you get back to it Thanks again for the reply.
'shorted' isn't exactly correct, but a cell with high internal self-discharge. The bad cell will show up in a discharge voltage curve, or if you set it on a shelf for an hour, day, week, etc eventually it will settle to a voltage of about 2.2V too low.
Some questions, can this be done with a laptop charger/AC Adapter 15V @ 6A? I have an interstate MTP-24 that is 4-5 years old, and has the last cell next to the positive terminal that reads 0.31V from the positive terminal to the plates/electrolyte. I've been trying a regular smart charger for a week on (daytime) and off (at night) and it drops to 10.8 in the morning. What should I do first, go and buy the 15V AC Adapter and do your desulfation method or replace the electrolyte and clean the battery out and then your method? Thanks for the great videos.
@@SinsBird Do you really think so? How can I test to see if it's shorted? You know what I'll try cleaning it out to tomorrow with distilled water multiple times.
@@Max2JZZX10R You already did. You know that the battery discharges to 10.8 volts and you measured the voltage of the bad cell which is 0.31 volts. Voltage of a fully charged cell is around 2.1 volts so 5 times 2.1 plus the bad cell 0.3 volts = 10.8 volts. If the cell wasn't discharging by itself because of a short in it it would charge and stay charged.
@@Max2JZZX10R Don't bother, it's not worth it, it's extremely unlikely it would help at all. Today's batteries have their positive electrode plates in pouches and lead particles that are shed over time are well isolated. The cell fell apart, disintegrated inside, probably because of severe corrosion, that is why it's shorted.
Can you repair optima batteries I've never seen an optima battery repaired optima battery has been the number one failure in the past I have not been able to repair an optima battery and I wonder why?
They are AGM so there isn't much to 'repair' aside from that they can be desulfated just like any other lead acid battery. The process is identical to what I show in this video aside from currents being a bit higher due to the larger battery size.
Anyone know if those aliexpress desulphate circuits work? I don't see how they could as they don't seem to charge the battery, only short the terminals at high frequency. But could be totally wrong
They don't work as advertised. The may work by simply overcharging the battery as shown here. It's kind of like reading marketing on a retail box of a kitchen appliance - it may mix your cookie dough adequately but it isn't because of the 'industrial motor' or the 'patented dual action mixing hook' or the 'pure copper windings for 300% more power'. Nah, it just mechanically moves dough around in a bowl.
Hello, your videos are extremely informative and THANK YOU! I have a golf cart with 6 8v batteries. How can I use the same concepts? I have the 48v charger from Club Car, but how can I deal with one battery at a time, both for charging and for a load?
That particular charger doesn't allow overcharging for extended periods of time (I know because I have one) so you will have to use a different charger if your batteries are sulfated from storage at low SOC. The best option today in my opinion is to purchase a power supply as shown in this video - it doesn't have to be this particular one, just one that can do 60+ volts to charge the full battery bank. Let it overcharge for a time and then drive the cart until it dies and repeat. If your range increases the issue was sulfation. If it doesn't your battery issue was something else this video isn't covering.
@@knurlgnar24 Hi, and thanks for your thoughtful reply. I was thinking about refurbishing them one at a time - my concern was that if I did them all, I would get them to "good enough" as a group, and one or more would still be needing work. Doing them one at a time would let me pay each one its needed attention. And I know I can use your 30v charger for them, but was wondering how to give the batteries an 8v load. My thought after I sent the original message was to get some 12v incandescent RV light bulbs and use those for a load (they would work as a load but just be dimmer than at 12v). Do you think this would be the most comprehensive approach, or am I overthinking it and that "good enough" is fine for this application? I don't think I can stomach that nice programmable load unit price for my few batteries. And driving the cart until it dies is a little problematic since I'd have to push it back to its corral... ;-) Unless there's a way to create a 48v load???
@@knurlgnar24 I had a thought about how to load only ONE of the 8v batteries. Could I just hook up one 12v car headlamp? They are 55 watt max and at 8v that would be 7 amps if they draw that much. What do you think?
@@knurlgnar24 I purchased this power supply, so I can deal with the batteries one at a time. I hesitate on the price of the load generator you use although I'd love to have that. How can I cobble together a recommended load for one 8v battery? How many car headlamps, for instance? And in series, or parallel?
Thanks for sharing! What do you think about reverse charging? I'm trying to recover for fun and study some agm ups batteries that are dead because they were on float charge for some year on the ups and maybe the ups charger doesn't manage the float charge properly and after 2-3 years batteries are dead. In this situation you approach can be useful? In the past, before whatching this video, the only way to let batteries accept charge was to reverse charge them, discharge and recharge with the proper polarity. One of these accepts only reverse charge even if I put 32v on it with correct polarity... another one that I "recovered" with reverse charge and after correct charge, emits an hiss from time to time under charge even if I use less current than the maximum rated initial current printed on the battery that is a FIAMM agm battery 12ah 12v.. another one was under forced charge at 22v and 0,5 amp (it is a 4.5ah 12v ups agm battery) for 8 hours a day for 5 days but still can't hold the charge.. in short, up to now no appreciable result, unfortunately... I will appreciate every advice you will give, thank you very much!
Interesting timing on this comment as I am currently doing some practical experimentation on reverse charging. There are whitepapers out there on the subject and it is absolutely legit if used properly in the right circumstances, but it has to be the RIGHT circumstances. Most UPS units overcharge the batteries and positive plate corrosion or water loss is the precipitator of failure and desulfation or reverse charging will not help. Reverse charging can improve plate activation or help the desulfation process though. It is more aggressive than the methods I typically use but I think I may have found a common use case for it hence my current testing. I think you're on to something here... BTW the 'hiss' you hear is likely due to the battery outgassing excessively. This could be due to a multitude of reasons but there likely isn't much to do about it other than add water as necessary. Sometimes an old battery is just an old battery. None of these methods are magic as you're well aware, they just allow us to make maximum use of otherwise discarded batteries.
Hi Is capacitor based chargers that many are claiming as good tool for desulfation, is that really effective (capacitor in séries with bridge rectifier and then output to battery )
No. They are not useful or effective. Simple constant current charging is the most effective way to desulfate batteries. That isn't to say such chargers do not desulfate in some capacity - I'm saying that they are inferior to simple constant current methods.
Ok thanks But is it true that this kind of circuit will put pulses of 170v (or 310 in cas of 220 v supply) and that will cracks plates so sulfate will dissolve once again ? Regards
@@knurlgnar24 Why would these chargers be inferior? These capacitive dropper supplies are linear circuits, essentially just constant-current supplies with high ripple. Ignoring the safety aspect of an unisolated supply, isn't this more or less equivalent to a classic dumb charger?
Good job making the video, it was very informative. What is your opinion on battery desulfators? I use a Pulse Tech PowerPulse passive desulfator, they claim to have a patented frequency they use to desulfate batteries, I have been using it on my BMW battery for the past three years and never have any issue's starting even though I only drive about 25 miles per week.
Glad to see you back! That intro music is the best, don't change it. I'm curious to see a demo of the battery capacity and output power of a recovered battery like this. What percentages can you expect? As for other properties, like self-discharge, do you have any predictions on what those could look like?
Part2 will have some, but not all, of that info. The video got long so I cut it short. Typically if a battery recovers it will have a higher internal resistance than when new and a lower capacity - the two are usually about the same percentage of new though it varies. Self-discharge is a wildcard in my experience. Most of the time you'll have no issues with it but it will almost certainly be higher by some amount than a new battery.
If a car battery charger only uses ~14-15 volts to charge and say 20-30 amps, why are the cables so heavy vs the cables on your CC CV power supply that appars to have 10 ga wire at most? Good video..
Modern car alternators can output 100A to 150A to power all the electronics cars have nowadays. Some can do over 200A. Heavy wiring is needed for such loads and the starter consumes many times more amps - though for a short time. 20 years ago there were instances of fires caused by inadequate design choices of wire gauge on vehicles. e.g. install a 'new' battery that was low on charge and it accepts the full 80A output of your 1999 ford escort and after 10 minutes straight of that current through the 10AWG wire they chose to use and you had a problem.
I actually have a video planned on converting an industrial power supply to a battery charger. I won't be comparing to an alternator setup but you can draw your own conclusions. In all honesty I'd personally recommend the dc/dc charger approach for most people. The alternator/engine approach is better for a prepper type as it's so simple, parts are easy to find, and it will last reliably for thousands of hours. On the other hand you never know when electronics will fail you.
@@knurlgnar24 Yes , agreed, the heavy duty ,upgraded alternators or dedicated secondary alternator like the #humbleroad van builder George, uses does simplify the charging system.I use a simple 150 amp breaker switch like you demonstrated ,manual off and on close to the driver's seat and a couple deep cycle batts. seem to work fine for me.After engine/ alternator is turned off the batts seem to drop from 14 to around 12.8 volts. But they power a low grade, 1000 watt so called "pure sine wave" inverter to run a cpap breathing machine all night. The voltage drops to only about 12 volts. I was surprised it worked! With the "Vandweller RV" craze still strong, your channel could help a lot of "do it yourselfers." Thanks for all your knowledge and tips and testing! Cheers from Vancouver BC.
hi, how can I contact with? I did same tes with AGM battery for UPS and added destiled water and tried to desulfate with High Constant Current process, and it works, I did it like 3 o 4 times round charge/discharge and now works even I measure the recover back to 100%, I want to know if AGM can be converted to wet cell
Would the marked max initial voltage always be the driving parameter or is a general maximum of 2A recommended? I have a larger battery with about 13A initial voltage, resulting in A staggering 156W!
The initial voltage is independent of the current you would use to desulfate. If it is a 12V battery of, for example, 100Ah instead of 7 as shown in this video then 2-5A would probably be an optimal current limit depending on a host of variables.
This battery is non serviceable (some people service them anyway and that is not covered in this video) but on batteries that do have removable caps water should be added before charging whenever the plates are not fully submerged, and once the battery has recovered a good amount then the water level can be normalized when at full charge. If one adds water up to the 'full' level on a sulfated discharged battery it will most likely overflow when charged/charging and make a royal mess. The important thing is to make sure the plates are never exposed to air when the battery is being charged or discharged.
Help please: I copy your settings on current say .095 then set 29.5v and it resets itself to 12.92v each time, what am i doing wrong please Tenma 72-2685 30v 3a I can not get a 30v charge no matter how I try
If you set the current limit to 0.095A then it will limit the current to 0.095A, and it does so by lowering the output voltage until current falls to 0.095A. It will always use the lowest current and voltage necessary to keep both current and voltage below the set points.
@@woodwood5164 How much is the current when the voltage is 12.92? If it's 3 Amps, then it's working perfectly and your battery can start recovering. Watch Part 2 of this video.
If you haven't bought a bench top power supply you are missing out, After you own one you will wonder how you ever lived without it, I can't say enough 😀
@@knurlgnar24 Thanks for your answer! I have one bad cell in my 12V 105ah DEEPCYCLE Battery. I drilled holes in the top... So I can check the fluid bubbling... but one cell is not bubbling... Is there a way to repair? Maybe with one of the machines you use..??
Thank you very much for the very helpful method. I have a 12V 12Ah battery which died and it didn't react on smart battery charger. Using your method I was able to recover the battery and use it. As I don't own lab equipment, 1st I have used 36V 4.5A adapter, the current was slowly rising from 0.01A to above 2 A over a day and battery gets very warm, batt. voltage at the end of the day was above 10V, which dropped to 8V overnight. So I started the cycle again next day. until the current rose to 3A, I stopped there as I don't own lab equipment, voltage at the end of the day was above 11V and dropped above 9V overnight. Next day I took laptop power supply 20V 4,5A and it took approx a day the current rose above 2A and batt. voltage was above 12V. Then I attached the smart charger, and it charged the battery overnight. I took few days but I can use it now.
That's great! I much enjoy situations where people use what they have on hand to accomplish things that ordinarily wouldn't be possible without some knowledgeable creativity. Sometimes the best hammer you have on hand is a wrench, and sometimes the best pry bar you have on hand is a screwdriver. It works.
Hip hip hooray the man is making videos!
There are thousands of us who are just happy to see you back Knurlgnar! You have always made the best inverter videos anywhere on UA-cam.
Thanks Drewboo!
I really missed your videos man. I'm a truck driver and your inverter videos helped me a ton
Thanks! You truck drivers are underappreciated in my opinion!
Pleasant surprise to see activity from you channel again. Always impressed with your knowledge and manner of presentation. Plz continue to share.👍
This is how I know we are headed to better times. Knurlgnar is back posting vids. Love it!
I'm glad to see you back. I find your videos very informative, accurate, and helpful. Production quality is not as important as the three things I just mentioned. Whenever you need a break or don't feel like doing videos, that's your prerogative.
Oh hell yes! Another
knurlgnar24's hands video! Saturday is saved!!!
Hi, excellent explanation. I hope you will also be doing switching power supply , chargers and inverter type repair videos like all the ones you did before. I very much enjoy your videos, thank you for the considerable time and effort that you must put into producing these videos for all of us that really enjoy watching them. I hope that the coming here will be very good and rewarding for you.
Hi , thanks for the video. you look expert on the topic, and all the reasonings sound correct. Do you have any link or literature on this? I would like to have more details on how much current should I set for a 100Ah battery, with several hour process. what is the dependance with temp and so on (I'm desulfating my camper batt)
Excellent demonstration video, greetings from Saudi Arabia.
Thanks for this. I have a 12v 20Ah SLA battery that I neglected and when I tested it, it was 6v. None of my smart chargers would touch it. I have a lab power supply and it never dawned on me to try that - even though I've used it before to charge batteries. Anyway, 24hrs later and it was taking 2Ah from the power supply. It's now charging on a normal charger which shows 20% charge. Even if it's not useful at the end of the exercise, it was fun!
the reason "smart" chargers don't touch dead batteries is because they don't see a load and they have short circuit protection built in because dumb people like to shock themselves or start fires. you can trick them into seeing a load by putting a high-wattage resistor or incandescent light bulb in parallel w the battery.
Yah
More please
One of the few trustworthy sources on UA-cam
Nice to see you back too! I loved the inverter reviews. I have learned that nearly all batteries that came from computer UPS's are usually toasted. I think they are just boiled dry. I have found a few bloated out too. The only batteries that stand a chance of recovery are ones that were simply neglected, under charged, sat on a shelf for 2+ years since new. There is no way of recovering a battery that has been cycled over and over to near dead everytime, or float charged at 15 volts like some UPS's can do. They're just pooped out.
I agree. Most UPS units are designed for battery changes every couple of years and they 'boil' them dry fairly quickly by floating them at a high enough voltage to recharge them relatively quickly after use but low enough to avoid the cost of a multi stage charger. The old ubiquitous APC Smart UPS units float them at around 14V from what I've seen.
All batteries can dry out which is a point that all battery manufacturers are aware of but never disclose to their customers. So when they say Gel and AGM are maintenance free, it's like saying transmission fluid is 'lifetime' fluid...yeah, for the lifetime of the vehicle which is a relative term. I think there needs to be more testing done by flooding AGM and Gel batteries to see how many if any are recoverable by adding water. AGM should have the best luck as I spoke with one manufacturer that told me they flood their AGM batteries with a typical water and sulfuric acid solution then dump out the excess in order for the battery to be classified as "AGM".
@@imzjustplayin Agree with your facts.
Knurlgnar rulz! Fantastic to enjoy regular content from you again - please don't burn out, you have lots of fans out here who understand if you need a break - just keep on creatin' !
Finally back thank God!
Just the video I was looking for. Thanks!
Yah a new video
Great to see you back 👍
I'm interested, just bought home a dozen of these from ups's that I picked up for a test run of my solar setup while I build the 18650 packs
Look forward to part 2
And hope you make more, I've watched All you back catalogue
Can't believe you made it through all of my boring monologues! I fear my love of lead acid batteries may become obsolete in time as lithium batteries get less expensive. :( I do expect insurance companies to ban lithium battery banks in houses in the near future though unless very onerous and expensive 'certified and inspected' government approved pre-built units are used. Unfortunately the law will likely blanket all types of batteries because government is lazy. Thanks lithium! ...
@@knurlgnar24 Haha, I thoroughly enjoyed them, a good mix of detailed infomation with your impressions thrown in, not long and boring but also not just edited highlights
I only came across you a few years back when I started getting some free laptop batteries, so it was your inverter tests that attracted me
Think I ended watching everything you'd published, so great to see new content
Agree with your thoughts on lead acids future, they've served us very well with little change over the years and are definitely far safer than lithium
Appreciate your reply, take care and wish you all the best
@@knurlgnar24 The 2017 National Electric Code has a new section 480.3 which reads as follows: "Storage batteries and battery management equipment shall be listed. This requirement shall not apply to lead-acid batteries."
Based on this, I would expect insurance companies to ban homemade lithium banks, but allow lead-acid. At the very least lead acid banks will almost assuredly remain legal. I really don't know what sore of wording insurance companies would use to ban lithium banks, maybe capacity would be a factor.
I was interested in the desulfation process. I wanted to look it up because I have a 7-stage charger and was wondering what is the Battery Desulphation mode is. And then, about 09:43 you are openening up some Dragons Milk! Oh wow haha! Nice, I had that before.
Still my favorite beer. It's like drinking a loaf of bread. Yum!
I have a feeling you are going to get noticed more in the near future. I would think of making more frequent videos on battery power and reviving.
Thank you for the comment. I'm mostly inactive at this time but am considering reviving the channel in the future.
good to see you back :) waiting for part 2, cheers 👏👌🍁🙋♂️😊👍😉
Good to see you back. Maybe you can do a video of you cleaning up your shop!
NEVER! The chaos is what makes me feel ALIVE!!!
@@knurlgnar24 i agree when I clean my shop I can't find anything
Nice to have you back
What happens if I leave a good deep cycle gel battery on a 15v desulfation cycle for an extended period of time?
Thank you in advance.
Gel batteries are very sensitive to outgassing so I'd guess the battery would be ruined if kept at 15V for an extended period of time. So long as the maximum charge specs for the battery are followed to avoid permanent gas pockets in the gelled electrolyte you'd be OK and the process should work - it would just take a long time since you're limited in how much current you can force through a gelled battery.
Since I have a bench supply, this works for me. Thank you.
I have saved so many batteries from certain death due to what I learned from your old videos.
What if you have a used battery that takes over 30w even when fully charged?
Going to miss the videos that you do. Out here in cyber space your work has been well received.
What voltage/current for lead acid cells?
Thank you. Very good explanation. It has shown me what I wanted to know.
It miight work to make desulfation unit?
Any differentiations on doing this for a 6V battery versus 12V?
Nope. Just a lower voltage. The rest is the same.
So I'm guessing that the bubbling is the conversion from Lead Sulfate back to Sulfuric Acid. At first it was chamber 1 (closest to the negative) and chamber 6 (closest to the positive) that would bubble but after several hours chamber 1 won't bubble at all. Is it chamber 1 finished desulfating or is it dead?
I am using a 12v/10a charger that has a brief 12v/50a engine start mode. I just keep switching between the 2. It's just interesting because at first only chamber 1 would bubble. Now it's the only one that doesn't.
I am attempting to recover a Absolyte 48 volt, 2000 amp hour battery... I am trying to learn this process. Is it possible to remove each 2 volt cell and independently charge each cell to a state of charge? I am hoping to achieve as many cycles as I am able. Am I out of my mind for even attempting?
Glad to see you back !!!!
What settings do you recommend for a car battery? 30v 2a for awhile?
The Florida pool pump motor bearing repair guy approved ! that was good info
I have a U1 12V battery that sat for at least 4 years from my snowblower. I didn't bother maintaining it since I have had a snow clearing service. Anyway, it has been stored indoors just to make sure it didn't freeze. It read just over 6V and I decided to charge it with my new Pro-Logix PL2320 (at 2A)...I had to see if it worked. (all my other chargers are low current chargers/maintainers). Incredible, it took a charge and then went into maintenance mode. I did a load test at 100A and it dropped to 10V which it held. OCV a day later is 12.60V. I have done a few charge and load test cycles. So far so good.
great video. i was trying this on a similar battery to yours. I had the power supply at 32v and it reached 1.3A then the current suddenly tanked all the way down to 200ma. Battery didnt seem that hot. Any explanation for this?
Do you think the high frequency current pulses does a better job at desulphating ?
No
i'll try this with my nackered old sealed acid batteries , they hold only a tiny charge and i do have an old charger and big 12v motor to discharge it , was thinking getting 2v cells from a forklift and trying those on my solar setup to get free power at night but here in scotland hard to find tham. thanks for posting
Since you apply more then double the voltage to the battery would it not be safer to keep the current to half the recommended current ?
Love the project room, a beer and el-Pussy-gato helping you out!
we'd all love to see you making videos man!!
i have two batteries a car 12v/40AH flooded type & a bike 12V 5AH maintenance free both cannot start the engines but do show the voltages, even get charged, can i fully recover them.
It depends on their history, but unless they sat unused for long periods of time their problems are likely not sulfation. Your batteries may have simply reached their end of life and need replacing with a new battery. Motorcycle batteries in particular tend to have short lives as they usually use higher acid concentrations to boost performance at the trade-off of useful life.
Welcome back, knurlgnar!!! Always good informative pertinent video presentation greatly missed.
Would this work if a vehicle battery is at 550 CCA when rated at 710 CCA?
Probably not unless the battery is only low on CCA due to sulfation. The most likely scenario is that the battery is simply old and needs replacing soon. Then again 550CCA should be plenty for most any vehicle even during the winter.
Welcome back, good to see that u ok and doing videos again
Great video, I will have to try this method on a couple batteries I have kicking around, worth a shot, but I wonder if the old timey unfiltered DC (pulsating) charger would have a better chance at desulfating?
@Thomas Chrombly But some of the newer "smart" chargers won't work if the battery is dead. The old "dumb" chargers which are nothing more than a trasnformer and rectifier will try to charge anything connected to it.
@@MRCNC1967 I have found that attaching a smart charger AND an extra voltage source will trick the smart charge to begin charging. Once it sees a base voltage, then remove the alternate voltage source and let the smart charger continue to charge. JwgK
When should cell caps be taken off?
Hay. I have no problem getting two car size lead flooded battery to a rest voltage of 12.4, 12.5 volts. The problem I have is when I hook up the battery to any load like 65W headlight. The voltage drops to below 12v immediately and I get at most get a few minutes before it get below 11 volts. Cycling does seem improve it. Are my batteries toast at this point?
If overcharging them and cycling them while keeping electrolyte levels topped off doesn't improve them then your batteries are likely 'toast'. They do have a finite life unfortunately. Sulfation is one of the most common abuses they suffer and THAT can be recovered. Worn out batteries that have lived a good life and have no more to give just have to be replaced.
@@knurlgnar24 These are fairly new batteries less than 5 years old. In my case here being able to get the rest voltage to 12.5v or above but with no capacity. You think overcharging it more would help. Because I stop over charging (switch to a smart charge) once I get the rest voltage to 12.5v.
@@bobcharles7716 you must measure the specific gravity of each cell with a hydrometer if you want to find out what is going on.
Very good video, please answer me I have the following problem, my laboratory power supply unit Wantpek APS3010H unfortunately only charges with CC until it reaches the closing voltage and then with CV and then the current drops, how did you set it so that you charge with CV and the current rises, thank you
Your power supply is working properly from what I can surmise from your comment. The current limit and the voltage limit are independent. If the voltage limit is reached current is lowered to prevent voltage from going higher, and if the current limit is reached voltage is lowered to prevent the current from going higher. It sounds to me that your batteries are not severely sulfated and are charging like typical batteries instead of charging like damaged batteries as shown in this video.
Hii very nice information, but i have question I use the gell battery when it is full 13.2 volts and get a load of 2a baterai drops 11 volts, how to fix it sir? Thanks
It depends on the battery. If it is a smaller battery that may be normal simply due to charge mobility and internal resistance, but if it is a larger battery, say 20Ah or larger then that isn't normal. Gel batteries are more difficult to restore as any 'bubbles' are permanent and damaging. To desulfate a gel battery you would need a very mild overcharge for a long period of time.
@@knurlgnar24 thank you for answering
the battery that I use is 12 volt 100a, when I charge it with 14.2 for a few seconds it is immediately full with a voltage of 13.2 volts. for 2 days the voltage is still 13.2 volts but when given a load of 2a it immediately drops to 12 volts, and then the load is released voltage back to 13 volts again, is this due to sulfation or maybe the cell dry?
I've used the method you used to recover battery before and it worked very well
thank you for your information sir
Good to hear from you again! The other aspect of voltage and Ah capacity is the internal impedance, especially when discharging.
Great point!
I fixed about 20 batteey in the last month and make some money.
I do not know how to Thank you sir for your effort and knowledge.
Thanks for the comment! So many useful batteries are destroyed every year which could be used instead to reduce waste, increase overall wealth, and help the environment.
knurlgnar's hands are back from hiatus now too! :D fun fact, Evervolt's old school 9 volt batteries used to have a black and white cat in their logo not unlike yours! so i'd say that's very appropriate! enjoyed the video and looking forward to how it turns out in part 2
If the battery is swollen from one side (one cell), can it still be recovered or is it done for?
I would recycle a swoolen battery. Please do not attempt to recover it.
@knurlgnar24 oh ok, Its hard to see as it's only one cell and barely swollen. I checked it yesterday after 24 hours of charging on a laptop charger using a light bulb to bring it down to 12v, it actually held a charge for once and lasted about 2 minutes under load before dropping to 11volts.
I can not get it to set to CV, it defaults to CC, is that the problem?
I watched part 2 and then came back to view part 1.....still good info. I have removed the cover and rubber caps ( valves ) to add distilled water with a syringe into the cells. Is there a way to check specific gravity so that I may mix acid and water to be close to original solution ? I did not know before about leaving some headroom over the plates for off-gassing to re-constitute. Thanks JwgK
Unless the acid actually spilled only a trace amount of acid should have been lost. Distilled water should be the way to go.
Hi, I been try this process on a battery of and on for the last few months and I think I gotten some improvement. The Battery is fairly new. And I have gotten a totally dead battery to have a standing voltage of 12.9 volts if it is fully charged. However the capacity reads 200-300 amps on a load tester and the battery is a 900 amp battery. It look like I have a very weak cell next to the negative terminal. When I look into the cell I see definitely sulfaction on the plates and I read very low SG on the cell, and I don't see any bubbles. So it look like I have 5 super strong cells and a near dead cell. So if I can fix this cell I am there. So should I try to keep cycling the battery more a hope to revised the last cell? Should I try Epson cell on the last cell? Should I try to flush and fill the last cell? And I heard I can remove some of the acid solution from this cell and replace it with distill water and keep cycling it and that would help??? thank you
I don't support adding any foreign agents into a lead acid battery as I see no evidence that it actually is effective overall considering all variables, but if you want to try it it's your property and I'm not offended. That cell is likely the primary sulfated cell and it's possible its just too far gone. You can always try to continue the overcharge and cycle approach but it doesn't work for all batteries. Sulfation causes non-reversible damage unfortunately. You clearly reversed a good portion of it already. The industrial approach would be to empty the single bad cell, wash, refill with distilled water, charge the single bad cell to remove sulfation, then refill with acid and charge that single cell to reform. Then rebalance all cells. I doubt that's practical for your battery.
When you are desulfating, to get the best result quicker are you supposed to be charging the battery at the same time its being desulfated? or do you want the processes separate? Thank you.
The charging step is what does the desulfating. Cycling the battery primarily does two basic things: 1: It allows you to judge your progress. 2: It physically stresses the plates causing shedding which exposes new active lead to the charging process, and helps to create stress cracks which allow conversion of additional sulfate into useful active material. Shedding isn't desirable but is an inevitable part of the process.
glad to see you back ...
I have an issue I can't find a solution for. I have an alarm in my vehicle. Having been out of work since 18OCT2020 I don't have a need to drive each day. So my battery has 12V but seems to have no current. It will not take a charge. Even using the 55A Starting circuit it will no even turn the motor. What would you recommend. Are there solar chargers that I could put on it to keep it up with the alarm pull?
I'd disconnect the alarm and force charge the battery for an extended period of time. Lead Calcium batteries (which are the standard for North America) refuse to accept a charge after complete discharge for a time until they slowly start accepting charge again. After that point you will still need to desulfate the battery.
you should call your self a professor.
question
i have a flooded battery i measure each cell with multi meter and only one cell give me -0.3 v instead of 2 volt.
can i recondition that cell assume i do all safety procedure by put negative terminal of lab power supply on that cell and positive terminal in the main positive terminal of the battery?
thank you a lot.
If you have access to each individual cell you can desulfate each cell separately. It sounds like you have a single cell inversion where the cell reformed in reverse polarity. This is pretty common and somewhat difficult to rectify unless one has access to the inverted cell. With lead calcium batteries in particular this is quite common as manufacturers add dopants to the 'good' cells to cause them to leak current as much as the 'worser' cells so that the user doesn't end up with the problem you have. Chemistries with higher intrinsic leakage currents don't need this dopant which only makes good cells worse. This disrupts the battery chemistry as they age and leakage rates change though - cost cutting right? Anyway, I'd suggest desulfating just that one cell first if you are able to access it. Be sure to keep the water to the proper level at all times. Wish you the best.
What is the recommended discharge current to optimally recondition a battery? Isn't it that there is some trade off between the long reconditioning time, amount of water evaporated, and the level of the good sulfur coming back to the electrochemical reactions? Please explain this part more.
The discharge current matters little. The overcharge amount will determine the water lost.
Attempting to desulfate a marine battery. Charged voltage at 13.5 volts but has no cranking amps so I am assuming it's badly sulfated. I bought a power supply and I'm pumping 16 volts 8 amps DC and the electrolyte is bubbling occasionally and as time goes on the amps are dropping, is this normal?
Sounds normal. Be sure to keep the water topped up. Batteries can't always be saved so you'll have to see if yours can.
My friend has a solar setup and we are wondering; do we have to disconnect each battery to desulphate or can it be done in situ? A very informative video, thanks
The general answer is that they should be disconnected from the system to desulphate but there are exceptions. If you have them in parallel then disconnecting is required in all cases. If you have, for example, a 48V system with 4 batteries in series then you don't have to disconnect them if you're careful. On that hypothetical 48V system one could choose to idle the battery bank at 100% SOC and then desulphate just one of the 4 batteries in the 4S configuration, but the bank has to be either disconnected from the load/charger or idling at float and 100% SOC.
Short answer is that batteries should be desulfated alone, disconnected from the battery bank. If for no other reason than they are going to outgass a lot and get hot, and it's probably better to do that in a safer location.
@knurlgnar24 Great answer, thanks
Thanks for pointing me to this video. The batteries I mentioned in my last message all test at around 12.5+ volts. I'm glad they are totally run down. Coincidentally the 20 batteries I have are from the same company they are leoch lpc12-75
I remember your comment but can't seem to find it - youTube mysteriously deletes things at will for unstated reasons. In any case those sound like very nice batteries and I hope you are able to restore them to useful condition and make use of them! I'd take those for my battery bank if I had the chance. :)
So, this type of lab power supply wouldn't work for restoring car batteries would it, with 100s of amps?
Yes, this would work well for car batteries. Car batteries only require a few amps to desulfate.
@@knurlgnar24 Ah, ok, thanks for that clarification. I suppose the importance of what you are demonstrating here is the higher voltage but only a few amps. Is this lab power supply then also sufficient for charging a regular car battery?
try the welder method? speeds things up............
I wouldn't recommend using a welder as a battery charger. They aren't intended for that and have a high inductance output which is dangerous for battery applications. (but good for welding)
@@knurlgnar24 THANKS-- i did see this method however....... dialed in to around 30A input: speeds up force restore/desulf. Thoughts? ua-cam.com/video/VYtkn-N_p4s/v-deo.html
Man where have you been!!!
welcome back
Would this work on my weak 6 year old AGM car battery? The car has start/stop with energy recuperation technology BS . Or is my battery just worn out? The car apparently only charges the battery to 80% so I’m wondering has it caused sulfation. Maybe the smart charging prevents that?
If you regularly drive your car and it hasn't been sitting unused or only driven a couple times per week I expect you simply need a new battery as they have a finite lifespan. 6 years is pretty good for a vehicle with start/stop. That's hard on a battery.
@@knurlgnar24 thanks for reply. Yeah the car does 600 miles a week. I also think it might have a high self discharge rate problem. I had interesting readings from the battery monitor when it was left sitting at the airport for a week.
I have 6 8ah 6v lead acid batteries. They are 6 years old and have never been used. The voltage dropped to around 0.5v each. I tried CC at 1a for an hour on each battery and all of them immediately dropped to 2-3v when I took off the charger. Is there anything else I can try before throwing them out?
I have a couple of videos on recovering sulfated batteries. They may be worth checking out. If your batteries are old and never used it is highly likely that you will be able to recover them to a condition that is slightly less than perfect but very usable.
@@knurlgnar24 I have seen them, they were definitely helpful. Over the last couple years your videos have saved me hundreds of dollars of batteries. Unfortunately it seems at least 4 of the 6 batteries have internally shorted in at least one cell. I just had one of them swell up like a balloon while I wasn't watching, lol. I guess I've tried everything at this point. The charging the voltage would slowly drop from 35v down to around 10v at 1a. The battery would stay just barely warm and then the voltage would drop to around 3v and the battery would get super hot in less than 20 seconds. This happed for 4 of the 6. Is there something I'm doing wrong or are these batteries just toast?
I have 2 of same battery with low capacity problems . Can i use my 28 volts printer adapter rated at 2 amps maximum to try reconditionning them ?
As battery prices in lebanon are getting very expensive .
Tnank you for the informations
Those adapters have a hiccup overcurrent protection mode, so you would have to add resistance between the battery and adapter to limit current to less than 2A. Be careful and be safe if you decide to try it!
just saw you have a ton of amazingly helpful off grid vids...
thanks muchly...
any hope for my crown 420ah l16s(2 in series at 12v)
that drop down to 12.6 volts after sundown due to my ignorance in having had an under powered pv setup when i got them?
they got drained down to 11.7v almost every night for the first month i used them and never got fully recharged during the day.
so now if i disconnect the charger they slowly drop down from @13.9 to 12.6 over a cpl hours with no load.
they will mabey loose another .1v overnight if i have no load but if i run them down to 12.2v they are still at 12.2 in the morning.
i feel like they are good candidates for salvation compared to what you used for demos.
can this be over a period of days on and off?
any help not ha having to replace this wasted 600 dollar battery bank would be greatly appreciated.
thanks.
I can pretty much guarantee that you can restore those batteries to near 100% without much trouble. If it's only been a few months of damage due to undercharging it will be almost completely reversible. I'd need a specific model number to give specific advice, but whether these are AGM, flooded lead antimony, flooded lead calcium, or pure lead makes a difference in the details. (I will assume flooded of some chemistry) The short of it is I would recommend disconnecting or turning off the solar and inverters and doing an extra long equalization charge. Crown likely recommends something like 5 hours for maintenance purposes but since yours are damaged they will need more than that - maybe a full day. Keep an eye on temperatures and electrolyte level during this time. If you have a hydrometer keep charging until sg stops rising in all cells. After that do a deep discharge, log the result, and do a normal full recharge followed by the crown recommended equalization charge. Repeat. Once your capacity result during the discharge tests stops rising you are done and given your situation it will probably take only 1 or 2 cycles. Obviously the most important thing is to not let them get damaged in the first place but life isn't ideal and these things happen - fortunately it's not a big deal as long as the situation is rectified in a reasonable amount of time.
@@knurlgnar24 thanks so much ....
I am completely off grid so I can't charge them externally
I can set my charge controllers
To equalization voltage for a few hours at a time a few days per week...will this eventually do it?
If not since I am switching to Chinese prismatic 3.2v x16 for 48v sometime this winter and
run an external charger then.
(BTW they are a pair of crown CR-430 6v in series.)
and these big fla are to expensive and too heavy to junk...
Awesome info ...hope you get back to it
Thanks again for the reply.
How do you know if you have a shorted cell? Will it heat up fast or how do you test for it? Thanks.
'shorted' isn't exactly correct, but a cell with high internal self-discharge. The bad cell will show up in a discharge voltage curve, or if you set it on a shelf for an hour, day, week, etc eventually it will settle to a voltage of about 2.2V too low.
@@knurlgnar24 Thanks for taking the time reply!
Some questions, can this be done with a laptop charger/AC Adapter 15V @ 6A? I have an interstate MTP-24 that is 4-5 years old, and has the last cell next to the positive terminal that reads 0.31V from the positive terminal to the plates/electrolyte. I've been trying a regular smart charger for a week on (daytime) and off (at night) and it drops to 10.8 in the morning. What should I do first, go and buy the 15V AC Adapter and do your desulfation method or replace the electrolyte and clean the battery out and then your method? Thanks for the great videos.
The cell is shorted, so your battery is done for.
@@SinsBird Do you really think so? How can I test to see if it's shorted? You know what I'll try cleaning it out to tomorrow with distilled water multiple times.
@@Max2JZZX10R You already did. You know that the battery discharges to 10.8 volts and you measured the voltage of the bad cell which is 0.31 volts. Voltage of a fully charged cell is around 2.1 volts so 5 times 2.1 plus the bad cell 0.3 volts = 10.8 volts. If the cell wasn't discharging by itself because of a short in it it would charge and stay charged.
@@Max2JZZX10R Sulfation on the other hand is about reduced capacity and increased series resistance, nothing to do with open circuit voltage.
@@Max2JZZX10R Don't bother, it's not worth it, it's extremely unlikely it would help at all. Today's batteries have their positive electrode plates in pouches and lead particles that are shed over time are well isolated. The cell fell apart, disintegrated inside, probably because of severe corrosion, that is why it's shorted.
Can you repair optima batteries I've never seen an optima battery repaired optima battery has been the number one failure in the past I have not been able to repair an optima battery and I wonder why?
They are AGM so there isn't much to 'repair' aside from that they can be desulfated just like any other lead acid battery. The process is identical to what I show in this video aside from currents being a bit higher due to the larger battery size.
Way to celebrate hard work.
Anyone know if those aliexpress desulphate circuits work? I don't see how they could as they don't seem to charge the battery, only short the terminals at high frequency. But could be totally wrong
They don't work as advertised. The may work by simply overcharging the battery as shown here. It's kind of like reading marketing on a retail box of a kitchen appliance - it may mix your cookie dough adequately but it isn't because of the 'industrial motor' or the 'patented dual action mixing hook' or the 'pure copper windings for 300% more power'. Nah, it just mechanically moves dough around in a bowl.
Hello, your videos are extremely informative and THANK YOU! I have a golf cart with 6 8v batteries. How can I use the same concepts? I have the 48v charger from Club Car, but how can I deal with one battery at a time, both for charging and for a load?
That particular charger doesn't allow overcharging for extended periods of time (I know because I have one) so you will have to use a different charger if your batteries are sulfated from storage at low SOC. The best option today in my opinion is to purchase a power supply as shown in this video - it doesn't have to be this particular one, just one that can do 60+ volts to charge the full battery bank. Let it overcharge for a time and then drive the cart until it dies and repeat. If your range increases the issue was sulfation. If it doesn't your battery issue was something else this video isn't covering.
@@knurlgnar24 Hi, and thanks for your thoughtful reply. I was thinking about refurbishing them one at a time - my concern was that if I did them all, I would get them to "good enough" as a group, and one or more would still be needing work. Doing them one at a time would let me pay each one its needed attention. And I know I can use your 30v charger for them, but was wondering how to give the batteries an 8v load. My thought after I sent the original message was to get some 12v incandescent RV light bulbs and use those for a load (they would work as a load but just be dimmer than at 12v). Do you think this would be the most comprehensive approach, or am I overthinking it and that "good enough" is fine for this application?
I don't think I can stomach that nice programmable load unit price for my few batteries. And driving the cart until it dies is a little problematic since I'd have to push it back to its corral... ;-) Unless there's a way to create a 48v load???
@@knurlgnar24 I had a thought about how to load only ONE of the 8v batteries. Could I just hook up one 12v car headlamp? They are 55 watt max and at 8v that would be 7 amps if they draw that much. What do you think?
@@knurlgnar24 I purchased this power supply, so I can deal with the batteries one at a time. I hesitate on the price of the load generator you use although I'd love to have that. How can I cobble together a recommended load for one 8v battery? How many car headlamps, for instance? And in series, or parallel?
Great informative video, thanks.
Welcome back!
Thanks for sharing! What do you think about reverse charging? I'm trying to recover for fun and study some agm ups batteries that are dead because they were on float charge for some year on the ups and maybe the ups charger doesn't manage the float charge properly and after 2-3 years batteries are dead. In this situation you approach can be useful? In the past, before whatching this video, the only way to let batteries accept charge was to reverse charge them, discharge and recharge with the proper polarity. One of these accepts only reverse charge even if I put 32v on it with correct polarity... another one that I "recovered" with reverse charge and after correct charge, emits an hiss from time to time under charge even if I use less current than the maximum rated initial current printed on the battery that is a FIAMM agm battery 12ah 12v.. another one was under forced charge at 22v and 0,5 amp (it is a 4.5ah 12v ups agm battery) for 8 hours a day for 5 days but still can't hold the charge.. in short, up to now no appreciable result, unfortunately... I will appreciate every advice you will give, thank you very much!
Interesting timing on this comment as I am currently doing some practical experimentation on reverse charging. There are whitepapers out there on the subject and it is absolutely legit if used properly in the right circumstances, but it has to be the RIGHT circumstances. Most UPS units overcharge the batteries and positive plate corrosion or water loss is the precipitator of failure and desulfation or reverse charging will not help. Reverse charging can improve plate activation or help the desulfation process though. It is more aggressive than the methods I typically use but I think I may have found a common use case for it hence my current testing. I think you're on to something here... BTW the 'hiss' you hear is likely due to the battery outgassing excessively. This could be due to a multitude of reasons but there likely isn't much to do about it other than add water as necessary. Sometimes an old battery is just an old battery. None of these methods are magic as you're well aware, they just allow us to make maximum use of otherwise discarded batteries.
@@knurlgnar24 Thanks for your reply! Then, can we soon expect a new reverse charging based video? 😁
Sweet Project Cars has desulfated many batteries with a method
So if I understand correctly, best way to charge a battery is to put very high voltage with lowest current possible ?
For desulfating that is an option. For general charging I wouldn't recommend this method.
Hi
Is capacitor based chargers that many are claiming as good tool for desulfation, is that really effective (capacitor in séries with bridge rectifier and then output to battery )
No. They are not useful or effective. Simple constant current charging is the most effective way to desulfate batteries. That isn't to say such chargers do not desulfate in some capacity - I'm saying that they are inferior to simple constant current methods.
Ok thanks
But is it true that this kind of circuit will put pulses of 170v (or 310 in cas of 220 v supply) and that will cracks plates so sulfate will dissolve once again ?
Regards
@@knurlgnar24 Why would these chargers be inferior? These capacitive dropper supplies are linear circuits, essentially just constant-current supplies with high ripple. Ignoring the safety aspect of an unisolated supply, isn't this more or less equivalent to a classic dumb charger?
Good job making the video, it was very informative. What is your opinion on battery desulfators? I use a Pulse Tech PowerPulse passive desulfator, they claim to have a patented frequency they use to desulfate batteries, I have been using it on my BMW battery for the past three years and never have any issue's starting even though I only drive about 25 miles per week.
Glad to see you back! That intro music is the best, don't change it. I'm curious to see a demo of the battery capacity and output power of a recovered battery like this. What percentages can you expect? As for other properties, like self-discharge, do you have any predictions on what those could look like?
Part2 will have some, but not all, of that info. The video got long so I cut it short. Typically if a battery recovers it will have a higher internal resistance than when new and a lower capacity - the two are usually about the same percentage of new though it varies. Self-discharge is a wildcard in my experience. Most of the time you'll have no issues with it but it will almost certainly be higher by some amount than a new battery.
If a car battery charger only uses ~14-15 volts to charge and say 20-30 amps, why are the cables so heavy vs the cables on your CC CV power supply that appars to have 10 ga wire at most? Good video..
Modern car alternators can output 100A to 150A to power all the electronics cars have nowadays. Some can do over 200A. Heavy wiring is needed for such loads and the starter consumes many times more amps - though for a short time. 20 years ago there were instances of fires caused by inadequate design choices of wire gauge on vehicles. e.g. install a 'new' battery that was low on charge and it accepts the full 80A output of your 1999 ford escort and after 10 minutes straight of that current through the 10AWG wire they chose to use and you had a problem.
The real deal is back!!! Would be cool to test the dc to dc chargers compared to direct alternator to house Batts in rv use.
I actually have a video planned on converting an industrial power supply to a battery charger. I won't be comparing to an alternator setup but you can draw your own conclusions. In all honesty I'd personally recommend the dc/dc charger approach for most people. The alternator/engine approach is better for a prepper type as it's so simple, parts are easy to find, and it will last reliably for thousands of hours. On the other hand you never know when electronics will fail you.
@@knurlgnar24 Yes , agreed, the heavy duty ,upgraded alternators or dedicated secondary alternator like the #humbleroad van builder George, uses does simplify the charging system.I use a simple 150 amp breaker switch like you demonstrated ,manual off and on close to the driver's seat and a couple deep cycle batts. seem to work fine for me.After engine/ alternator is turned off the batts seem to drop from 14 to around 12.8 volts. But they power a low grade, 1000 watt so called "pure sine wave" inverter to run a cpap breathing machine all night. The voltage drops to only about 12 volts.
I was surprised it worked!
With the "Vandweller RV" craze still strong, your channel could help a lot of "do it yourselfers." Thanks for all your knowledge and tips and testing! Cheers from Vancouver BC.
hi, how can I contact with? I did same tes with AGM battery for UPS and added destiled water and tried to desulfate with High Constant Current process, and it works, I did it like 3 o 4 times round charge/discharge and now works even I measure the recover back to 100%, I want to know if AGM can be converted to wet cell
ua-cam.com/video/br6I7QAkKpY/v-deo.html
ua-cam.com/video/ITZP8dfaXuk/v-deo.html
Would the marked max initial voltage always be the driving parameter or is a general maximum of 2A recommended? I have a larger battery with about 13A initial voltage, resulting in A staggering 156W!
The initial voltage is independent of the current you would use to desulfate. If it is a 12V battery of, for example, 100Ah instead of 7 as shown in this video then 2-5A would probably be an optimal current limit depending on a host of variables.
When should water be added?
This battery is non serviceable (some people service them anyway and that is not covered in this video) but on batteries that do have removable caps water should be added before charging whenever the plates are not fully submerged, and once the battery has recovered a good amount then the water level can be normalized when at full charge. If one adds water up to the 'full' level on a sulfated discharged battery it will most likely overflow when charged/charging and make a royal mess. The important thing is to make sure the plates are never exposed to air when the battery is being charged or discharged.
Help please: I copy your settings on current say .095 then set 29.5v and it resets itself to 12.92v each time, what am i doing wrong please Tenma 72-2685 30v 3a I can not get a 30v charge no matter how I try
If you set the current limit to 0.095A then it will limit the current to 0.095A, and it does so by lowering the output voltage until current falls to 0.095A. It will always use the lowest current and voltage necessary to keep both current and voltage below the set points.
@@knurlgnar24 thanks mine is 30v 3 amp, how do I force 30v in for 10 minutes safely please
ps it locks onto cc not cv like yours Rockseed 305p 30v 5amp (ignore typo above)
@@woodwood5164 How much is the current when the voltage is 12.92? If it's 3 Amps, then it's working perfectly and your battery can start recovering. Watch Part 2 of this video.
Do you think I could do this with a 36 volt scooter charger, 1.5 amp?
Doubtful, the charger will likely refuse to charge it.
If you haven't bought a bench top power supply you are missing out,
After you own one you will wonder how you ever lived without it,
I can't say enough 😀
Great video. Thank you
do you have a link to a resistor used in prior video?
I've Really Missed Your Videos.
What a cool video!
Can I use that Digital Led charger on a 12V 105ah DEEPCYCLE Battery (VDC31M) ?
Yes, the power supply shown here would work for that battery just the same as this little one - it just might take longer.
@@knurlgnar24 Thanks for your answer!
I have one bad cell in my 12V 105ah DEEPCYCLE Battery.
I drilled holes in the top... So I can check the fluid bubbling... but one cell is not bubbling... Is there a way to repair? Maybe with one of the machines you use..??
@@knurlgnar24 And is it wise to buy a heavier KORAD power supply for my 12V 105ah DEEPCYCLE Battery?