I've done that.Good job Adam 's been sensible & fused it all, be a shame to see all the nice wiring melt. Hinged cover of wood or plastic over the bus bars might be an idea for anyone mounting the bars flat, in case a metal object fell on them.
Love your videos Adam. I love your 3D printed busbar holders. I would recommend however to fabricate a bus bar cover for the positive terminal at least in case of bridging from falling metal pieces, etc..neat set up you have 😺
Adam Welch I really like your captive nut holders for a very solid connection. I thought you might thread tap the aluminium bars, but your set up is much more secure and won't strip out the bars. Very impressive.
wow... just coincidence.. I was looking at my battery bank and thought hmmm don't like it's setup. decided 2 solid copper busbars would be better. AND fuses for each battery. nice to see your video on this.
There is no such thing as over engineered project, I'm all about wires that look neat and pretty. And that bus bar is awesome.. how i wish i also have a 3D printer to make one like that.. amazing project!
Yes that's a really useful thing about what you've done Adam. Piece of cake to isolate each battery & check it with a conductance tester or whateve. You've got a super system for a lowish current draw set up now, worth all your effort.
For that ‘tight’ positive lead on the right, you could just loosen and rotate the bus bar end of it anti-clockwise, so it is pointing towards the battery - that should give you a little slack and less strain on the terminal crimp too. I’m really enjoying this series of videos- keep them coming 😊
Cheers Graham. Since making this video I have replaced this cable to give more slack. Still getting positive results with this setup too. Thanks for the nice comments and the suggestion.
Hope you also have main breaker/fuse or 50 amps so you don't blow all the small fuses if a large motors surge puts out 100 amps for 2 seconds systematically blowing all the fuses.
Hi Adam, i like the fusing individual batteries idea. Always good to have fuses. Worthwhile for people to put an LED + feed resistor in parallel with each fuse to show if a fuse blows, so it doesn't go unnoticed & just leave 1 battery not contributing to the bank.Ideal for a low current set up without massive thick cables like yours. I didn't fuse each individual heavy cable to each battery for my 3000 watt inverter. As you know (but others may not) each terminal crimp,connector & fuse adds a small voltage drop. The Smartgauge website has some interesting stuff on this. It surprised me just how bad this chap found the losses could be at heavy currents, when the total is maybe 200 or more amps for batteries wired in parallel.The losses on my set up are low, but over time with corrosion in the crimp terminals etc it could be a problem. I 've fixed quite a few Dragon rechargeable searchlights, like the police use. These can draw up to 8 amps (100W) & have push on crimp terminals to the cut-out circuit board. After years of use it was possible to lose up to nearly 0.1 v at every crimp.With wiring, the fuse/holder, relay, battery connector & loads of crimps you could end up wit 12v at the battery but less than 11 v at the bulb.Fitting new crimp terminals etc. improved this a lot. Thanks for an interesting video, regards.
Meant to add , always best to solder the crimps like you've done to avoid poor contacts inside, as years go by. Commercial products often don't bother for manufacturing speed. I've noticed that the pre- crimped heavy cables people buy for car starter motors etc. often aren't soldered. You can sometimes only easily tell by removing the heat shrink on them & looking, Fuse indicator wise, I was thinking of a separate mounted little box with LED's in a row connected across each fuse with a resistor. More work , but if someone was starting from scratch, the thin wires to the LED box could go in the same crimp connectors .Should indicate if a dud battery blew a fuse with a shorted cell. Enough voltage difference to light an LED. I don't think shorted cells are that common for lead acid batteries, but it does happen. A 10v or so faulty battery with the higher 12V + ( 14 v+ on charging,) common line, should light an LED.Your 3 D printing is great . I wish I had one.
I don't think it is over Ingineered at all. In fact I love it, you did a really great job. I think you should start making and selling them. LOL. Seriously though I do think that would be something to think about. I would buy one or two for sure!
+charles howard Cheers - not sure I want to start manufacturing them really, the time it takes means a low return. You'll have to get yourself a 3D printer. Once you do you find there's all kinds of things you want to improve! :-)
Nicely done, Adam. You might find that the batteries are taking/delivering slightly different currents because of various factors. There will also be some current flow from one battery to another. These things are inevitable, but you've done what you reasonably can to minimise future problems. As for the tight spacing, maybe Aluminium plates between batteries, a radiator, and even a cooling fan could be used when under high load or high ambient temperatures. If you're not pushing them hard, the batteries should be fine as-is. They have far harder lives in cars!
A very good point - engine bay temps can get quite high (and pretty low too)! Aluminium plates is a nice idea - I'd just need to make sure they were clear of the terminals. My batteries tend not to be under very high loads at all and you must remember, I live in England - high temperatures aren't all that frequent either! Cheers
Hi Adam i know it's a old video but perfect work. Current flow between batteries would be ideal hence balancing. Plans for my future powerwall thinking of going lipo4 100amp cells. Just starting now on building 18650 mppt 100w solar for shed power so your video's have been brilliant thanks. In progres of building ebike aswell. Any mppt solar chargers that will work with a dc wind turbin 120w 10 amp. Cheers thanks
+Arnþór Gíslason Its typical for a fuse the get hot and the surrounding metal will always serve as a heat sink (that's why fuses always blow in the centre) but I'm running these at fairly low currents. My battery bank breaker is 63 amps and that's to accommodate an over current situation on my inverter (it can handle twice it's rating for a few seconds) but if I draw much more than 40 amps for a while it will cut out. I expect these fuses will never see their full rating for more than a couple of seconds. Thanks though - i'I'll keep an eye on them when I'm pushing my inverter.
Great one I like it I did something similar to the 24-volt bank I got in the house but this is great I'll do that in the garage since I had 4 12-volt batteries in parallel and the middle one died and drained the outer to
Koodos! Now ya just need to make another 3D printed part: a cap to cover the whole strip so nothing "accidentally" touches both bars at once. Which would only happen when you're in there doing some kind of maintenance. Unless you wanna do like Pete did and make sparkles :P And, of course, it's sunny when you can't use it, and raining when you need the sun :)
Neat. I see many battery banks (videos) of guys fusing each string and/or battery in their respective banks. When I re-did mine (a few months ago) I added one ANL fuse (200-amp) for the cable going to the busbar (Blue Sea Systems) and then up to the main DC disconnect. I did a recent video on this. I am wondering if I should fuse each string? Fusing each battery would get awfully expensive. Thanks...your shed system looks good.
Cheers Chris. The worry is if one string fails for some reason or if you create a short across one string the other strings can also deliver current in that direction if the strings aren't individually protected. My system is quite a bit smaller than yours - and it has considerably less current to deal with so individual battery fuses isn't so much of a cost issue for me. For your setup I think it is worth considering a fuse on each string (I think you have three?) for piece of mind.
Hi Chris, Adam's done a terrific job fusing 17 AH batteries. I have over 35 large (around 100 AH) batteries feeding inverters up to 3 kilowatts. I thought about lots of fuses, but decided against it. The trouble is, at high currents the fuses/ holders, cable & crimp terminals, all cause voltage drops & imbalance. This only gets worse with age, as the contacts tarnish etc. Switch contacts, circuit breakers, they all suffer from it , plus of course the bolts can loosen with time. Even without the vibration you get in a vehicle, terminal bolts somehow still can sometimes need re- tightening, even on a static battery system. I personally wouldn't individually fuse the batteries on a 200 amp or so system. It's just more to give trouble. Smartgauge on the Net has interesting stuff on parallel battery Imbalance.Even with cable of 30mm sq or thicker , his results are surprizing. Cheers.
hey adam you can drop the gauge wire down as well because of load share tie your batteries in pairs instead of singles but do the same and keep the cables the same length. Keep in mind as well path of least resistance the point where the batteries as closer to the inverter those batteries will be drained first and the farthest will play alot of catch up under high loads. Also the first to get drained is the first to get charged and also the first to fail.
I use flattened legnths of copper plumbing for my buss bars. Make friends with your local plumber and you can probably get more 1'+/- cast offs than you could ever use. If you really wanted to be finicky about it one end of the lead could be soldered right into holes you drilled.
Hi Adam, I am a new subscriber looking into your old videos. The wiring seems to be small if you have an inverter but is that because each battery is now going through the busbar?
Yeah, with the batteries in parallel each one was delivering only a small amount of current which adds up to to a much larger current on the bus bar and the main positive and negative cables. Each battery was fused at 10amps if I remember correctly giving around 80amps available for an inverter.
I am trying to build a lead acid balancing circuit using a dedicated SMD chip. Might be over kill for this, but I will try and find the info on the chip and post. We are using it to try and extend the life of a 36v battery setup 6x6v golf cart batteries
Oww, and did you sand the surface of the bar before screwing the terminals on? Allu likes to form a nice oxidation layer :s Or if you want to make it real fancy (and have a new project :D ) copper plate the bars with electroplating :D
tengelgeer sanding and then using an anti-oxidant compound may be another option. Good thinking. May not be a huge deal on the smaller lead, but the main lead yes.
+tengelgeer, Bare Aluminium, when exposed in a Nitrogen atmosphere, has a beautiful pale yellow colour. When Oxygen contacts it, an oxide layer forms instantly, giving it the greyish-silver colour we are familiar with. Roughing the surface just gives more surface area on which that oxide will form. A good pressure contact will cut through most of the layer, and allow a decent electrical connection as the metal partly welds to it's connector. Aluminium is a very strange metal, which has a continuously moving surface when viewed under an electron microscope. And it also migrates when current flows through it. In one of my jobs, in the 1970's, we used ultrasound to weld Aluminium wires to transistor surfaces. NASA are using the same phenomenon on a macro scale for what they now call 'friction stir welding'.
The issue with this new configuration is that each battery will never have identical impedances, therefore during high load discharge it is possible for more current to be supplied by one of the batteries than the others, additional this may also cause the fuse from the battery to fail.
I wonder if you could compensate for this - the difference is going to be a fraction of an ohm. If you get all the batteries to an equal full charge you can measure the internal resistance of each and make up a length of wire per battery to compensate.
The trouble with Aluminium is that contrary to popular belief, it is actually really quite reactive and quickly forms an air tight, insulating oxide layer within seconds and your connection will deteriorate over time unless it is correctly sealed (i.e soldered or electroplated). That's why copper coated aluminium cable is such a problem. Squashed 15mm copper plumbing pipe would be a better option than that Al bar.
Adam, please see my response to tengelgeer. A good tight screw terminal will partly weld Aluminium to other metals. As long as the connection is kept dry and salt or acid-free, you should not have too much trouble for a long time. Once you encounter moisture, coupled with a salt or acid (or metals such as Mercury or Gallium), the contact will deteriorate rapidly.
Where do you get your bolts from? i've tried a few local diy places and couldn't find any. I built a wind turbine recently which needed lots of different sizes/lengths and it was a chew on buying bolts so had to get a kit from Amazon although not the cheapest. Like the design and kudos for designing your own kit!
Cheers Colin. The bolts were m5 16mm Cap Screws from Toolstation (item 29995) and I used their m5 nuts too. I've one not too far form me but it's free delivery if you spend £10 anyway. I'm accumulating a decent biscuit tin of various sizes and lengths of bolt now from various projects and using the why buy one, buy many philosophy!
Hi Colin, yes Toolstation is great. Another good place for all sorts from connectors to hardware & semiconductors etc. is CPC Plc (Preston). You only have to spend £5 (ex VAT) online for free postage . I have one of their catalogues & it's A4 about 2 inches thick!
I had the idea of giving each battery a chunky MOSFET or several on the negative, gate pulled down with a high-value resistor, and pulled up by a piece of thin wire running taut around the battery. Why? Because lead-acid batteries do fail, and when they fail they often fail in such a way as to swell slightly. Swelling that would snap the wire wrap, turning off the MOSFET and effectively isolating the battery so that its demise cannot damage any other batteries.
Hey Adam, can you please make a Fade-in Fade-out LED (Strip) Dimmer and sell the kit on your site or put an affiliate link so we can buy the parts? THANKS!!!
+Zen Zen That's a good point. A few ways I can think of. Open the fuse holders up and try to look from the top - might be a little tricky to see. Grab my multimeter and check continuity between the negative bus bar and each battery negative terminal. Or finally run a load and use my dc clamp meter around each batteries wire to check that each battery is delivering some current. There might be some improvement to make here - thanks.
Would be nice if you could somehow rig up a resistor/LED arrangement across each fuse as an indicator to show if it has blown. I've seen this on equipment many moons ago so I'll do some digging :)
Various circuits around for this on a Google search, some better than others, but the easiest thing I've found are blade fuses with a built in LED that lights up when the fuse has blown :) You would then just need to drill a little hole in the fuse cover so that you can see it easily. www.autoelectricsupplies.co.uk/product/854/category/157
Yes , that's what I was thinking & suggested before I noticed your comment. Sometimes you get a faulty fuse or holder. Be a shame to damage a good battery by not realizing that it was not being charged & got sulphated, just for a fuse.
I wonder if the resistor in the lighting up blade fuses would be low enough to make it light in this set up? There'd only be the voltage difference between the bad battery /good battery line. Probably only 2-4 volts in most cases, a bit different to most applications where the fuses are connected to just one 12v battery.
Decent video at all... Adam did you wonder about temperature sensor to each battery and INA219 sensor to each negative battery connection? I think that it could be interesting for few pounds... :-) don't you think?
Adam Welch - and also you can add a relay to each battery to switch off battery that is working somehow strange automatically... :-) and next idea - I would recommend to use copper bars, aluminium is going to sneak away from compressed connection over time. And the last one - I would consider to make a battery box out of Fermacell boards. This material is fire resistant and quite cheap...
Yea, short Bus Bar is the means. Utilizing Aluminum somewhat defeated the purpose. LOL I use Aluminum Bar like that with little to NO ISSUES. Not quite as conductive as Copper but using over size corrects that issue. CHEAP ! Employ Conductive Adhesive used for Auto Window Heater Elements insures electrical Bond for years.
I have golf cart batts. in series. for 24v. it helps the inverter efficiency. but now I need buck converters for my 12v led lights. any advice for a good cheap buck converter that will last. I have about 10 16' led tape strips. and 4 are RGB. so I need about 30-40amps at 12v. I would like the most efficient design. or I may as well use my inverter. I also have a low voltage relay on mind. at 30 amps 24v. to shut off at 22v. use this with a 30 amp or multiple 10amp units. what ever is most efficient . power consumption wise. great videos very inspiring. makes me want to finish my off grid home. and move.
I pretty much tested this exact thing a little while ago - although not to the level of current you are thinking about. If you use a load output of a solar charge controller that should give you the low voltage disconnect you require. ua-cam.com/video/dZHuj3R-g9A/v-deo.html
Thank you. The quick answer is yes, but probably relatively small. You take the main positive and negative at opposite ends of the string to even out the load. If you took both from the same end the first battery would deliver the most current, with the second delivering the second most etc. etc. The last battery in the string would in theory remain the least discharged, but also the least charged - so ultimately lowest cycles. Now in reality, it will probably feed its current into the next battery up, as will that one - so left to sit for a while they'll all become pretty even again. Although for current to flow there has to be a potential difference - so one battery must be higher than another. As I said ideally you connect all batteries to the same bolt to reduce the increased resistance between each leg in the ladder. Sadly that's really messy and not always possible, so I went for the second most ideal option I could come up with.
Hi Philip,it won't make much difference with smaller batteries like Adams .According to Smargauge, this sort of thing makes a huge difference with several large (N.B. say,100 A.H batteries) wired in parallel for big inverters. In one instance one battery delivered twice the current to another according to this guy for one (bad) method of wiring. I still find it hard to believe that It's THAT bad, but Smartgauge say they've done proper tests & it really is, even with thick cable etc. cheers.
As much as I like your setup and I really do, I would at least change the nuts, washers, fuses and bolts to copper because the current is only as good as the weakest link, which in this case would be the connectors at the end of each wire and the nuts and bolts... Why worry about all of this copper if the connections is of inferior metals? I have the same setup as you showed when you had them stacked where you thought you were running out of space... I have 2 holes drilled thru a piece of wood long and thick copper bolt, my buss bars and I added copper washers between the copper connectors with a copper washer and a copper nut at the end. The copper washers between each of the incoming wires spaces it just enough so there's no issues of overlapping each connector. My fuses are even copper and connect to copper holders. I have batteries on each side with my copper bolt "buss bars" in the middle of the of the two sets of batteries. I repair computers so I'm not perfect, but it boils down to common sense. I have people that bring in electronics with various connections like USB and 3.5mm headphone jacks and they have cables coated with gold and I explain the USB and most 3.5mm jack are almost just regular metal and a magnet sticks to the connectors most of the time so the quality ends there, I know the connectors you're using here is not magnetically conductive, but of cheap metal and does no justice to your hard work.
MrBrymstond as an industrial electrician I have built systems that carry thousands of amps, and the bolts (specced by engineers) are always mild steel, as copper or brass do not have enough tensile strength. the important part of an electrical connection, as in this setup, is the connector to the bus bar. The bolt should carry no current. Here in Australia, it is in breach of the wiring wiring rules for a connecting device (I.e. a bolt) to form part of a current carrying system. Your comments regarding computers/audio is totally different. You are talking about signal level (Or radio frequency transmission) and connectors are always the weakest link, therefore should be of the highest quality.
Cheap tin does not carry the amperage as well as copper, nickel, lead, silver or gold or why would you worry so much about the bus bar and the nickel strips on lithium batteries? The quality stops at the weakest point, tin.
i just did a very similar setup using the next size down in batteries, I have 2 banks so far both containing 6 batteries each. I have the charging off a solar panel in conjunction with a car battery that is charged from a separate panel. I have only just finished the setup and only visit the property occasionally so im yet to test. Is the idea that this will hold greater power than a single car battery? I did this because the batteries were free so I wouldn't have thought to do this otherwise. Is there a benefit to separate cells in this format or would the ideal setup be a deep cell truck battery or li-Po battery?
Note - Old alarm systems are a great place to get the small lead 12V batteries cheap or for free if your lucky. they are always kept charged and only the highest quality is used, however replaced in the new system so alarm companies have tones of them.
I have been given 2 batteries built from 84 LG Chem 60 amp hour pouches configured as 14s3p I want to keep them in tip top condition until they get connected as a household powerwall. Something like this would slowly charge them, but should I take them to say 70% charged and every so often check them, or charge them to say 47 volts and have them discharging through a small load down to say 42 volts then repeat, and how big a load should I use? I was thinking a couple of 24volt bulbs in series. I also have some configured as 3s4p that need looking after. I need a bigger shed
We all need bigger sheds Roger! If you are storing your lithium cells for long periods it’s best to charge them to a mid cycle storage voltage (for example I’d go for about 3.8 volts for lithium ion). That’s how most new electronics are delivered and stored. This will also allow you to see after a few months of any of the cells are self discharging more than any other. Cycling your cells, even only lightly will reduce their service life. It’s a chemical reaction after all and the process can’t go on forever.
I'm not sure that is true if you think about the resistance. Battery one is close to the main positive so has a low resistance with respect to it's neighbors, but the highest resistance on the negative with respect to its neighbors. Moving down the string that ratio changes , but overall the total resistance per battery should be roughly the same. Corner to corner connecting is pretty standard and generally seen as the easiest method to ensure even drain.
Adam Welch I thought that an even length between each battery and the main negative and positive leads would ensure same amount of distance between each battery and the main lug... Kind of like a Hammock between two trees the negative and positive leads fan out into the middle of the Hamic with multiple lines so that the batteries are along those lines and even length. My opinion...
Nice! Looks really good! But is it just my OCD that finds it ridiculous annoying the spacing of the holes is different... Especially because it would have been an easy fix by just drilling the holes of both bars at the same time by stacking them....
+tengelgeer Thanks. They were drilled offset to try and space the positives and negatives a little and to give the space required for the larger main crimp. Not sure it worked though.
Uhm.. that's not how batteries works. If you have 6 batteries in parallel, no mater what point you connect the load, the load across the batteries will be equal/the same. Same goes with charging, if they are in parallel, all the batteries will receive the same amount of charge, and they will equalize given a little time. No amount of fusing will change that. If you connect 1 low battery in a bank of 6, the other 5 will discharge into the 1 low one until all reach the same voltage/level of charge. If you have a shorted out battery in your pack.. all 6 will drain to the same level as that one. That's why you should only use 1 type of battery in a pack, never mix batteries of different type or age. You can mix batteries of varying capacity with no issues. But they have to be the same type.
Hallo adam i like your video but in this case this is not save suppose there is a Mouse don 't dak where she com from but belief me she going touch your two bars and then bang You have a dead Mouse make between the two bars 50 cm and put direct after the fuse a switch That can break the red and the black wire now You can change one battery safely
That really isn't an issue for a 12v dc system. I can touch both buss bars at the same time without getting any type of shock. I don't believe a mouse is anymore conductive than my finger.
The batteries being right up against each other is absolutely fine. if your having trouble with high battery temp you have charger issues or bad cells in one or several batteries. the biggest problem i see is your wire is way to small and too long. your losing efficiancy ...
+Flo I did consider this but my tapping set seems to be absolutely rubbish. The nut brackets are a bit silly but I was very pleased they worked so well. Cheers
I think it's insanely over engineered. If some bloke ask you to use a BMS tell him to piss off. Your setup was fine the way it was. Now, if we were talking 18650's ? Well, I might agree as they can explode!
if you want to make like adam you should to pay 10.000 USD just for 3D printer and 300 USD for the battery and many thing why you don`t call the super hero to make a Miracle battery bank for you !!
I learnt the interesting way to keep bus bars at least spanners width apart.
Haha! I'm using a screw driver or allen key to do mine but yes - perhaps I should have thought of that!
I've done that.Good job Adam 's been sensible & fused it all, be a shame to see all the nice wiring melt. Hinged cover of wood or plastic over the bus bars might be an idea for anyone mounting the bars flat, in case a metal object fell on them.
Love your videos Adam. I love your 3D printed busbar holders. I would recommend however to fabricate a bus bar cover for the positive terminal at least in case of bridging from falling metal pieces, etc..neat set up you have 😺
+threeparots1 Cheers. Yeah, let me have a think about that - it's a good idea.
Adam Welch I really like your captive nut holders for a very solid connection. I thought you might thread tap the aluminium bars, but your set up is much more secure and won't strip out the bars. Very impressive.
+threeparots1 Thanks :-)
wow... just coincidence.. I was looking at my battery bank and thought hmmm don't like it's setup. decided 2 solid copper busbars would be better. AND fuses for each battery. nice to see your video on this.
Great minds!
There is no such thing as over engineered project, I'm all about wires that look neat and pretty. And that bus bar is awesome.. how i wish i also have a 3D printer to make one like that.. amazing project!
Great idea. Can remove a single battery without breaking the whole chain 😊
+Big Bill Indeed yes. Hopefully this won't ever be needed but it may well come in handy.
Yes that's a really useful thing about what you've done Adam. Piece of cake to isolate each battery & check it with a conductance tester or whateve. You've got a super system for a lowish current draw set up now, worth all your effort.
For that ‘tight’ positive lead on the right, you could just loosen and rotate the bus bar end of it anti-clockwise, so it is pointing towards the battery - that should give you a little slack and less strain on the terminal crimp too.
I’m really enjoying this series of videos- keep them coming 😊
Cheers Graham. Since making this video I have replaced this cable to give more slack. Still getting positive results with this setup too. Thanks for the nice comments and the suggestion.
Nice work Adam, I want to build a solar shed myself now using some of your great ideas.
Thanks, keep the videos coming.
+Richard Boyce Cheers Richard and good luck.
VERY nice design. I love it. Good job on the 3D printer and of course your custom design.
Thanks Mr. Addict! Glad you liked it.
I like this idea for connecting the batteries. Thank you for the video.
Still working well for me. Thanks.
Hope you also have main breaker/fuse or 50 amps so you don't blow all the small fuses if a large motors surge puts out 100 amps for 2 seconds systematically blowing all the fuses.
+pirucreek Yeah I showed the breaker near the end of this video. It's 63 amps - less than the total of the individual fuses.
Hi Adam, i like the fusing individual batteries idea. Always good to have fuses. Worthwhile for people to put an LED + feed resistor in parallel with each fuse to show if a fuse blows, so it doesn't go unnoticed & just leave 1 battery not contributing to the bank.Ideal for a low current set up without massive thick cables like yours.
I didn't fuse each individual heavy cable to each battery for my 3000 watt inverter. As you know (but others may not) each terminal crimp,connector & fuse adds a small voltage drop. The Smartgauge website has some interesting stuff on this. It surprised me just how bad this chap found the losses could be at heavy currents, when the total is maybe 200 or more amps for batteries wired in parallel.The losses on my set up are low, but over time with corrosion in the crimp terminals etc it could be a problem.
I 've fixed quite a few Dragon rechargeable searchlights, like the police use. These can draw up to 8 amps (100W) & have push on crimp terminals to the cut-out circuit board. After years of use it was possible to lose up to nearly 0.1 v at every crimp.With wiring, the fuse/holder, relay, battery connector & loads of crimps you could end up wit 12v at the battery but less than 11 v at the bulb.Fitting new crimp terminals etc. improved this a lot.
Thanks for an interesting video, regards.
Meant to add , always best to solder the crimps like you've done to avoid poor contacts inside, as years go by. Commercial products often don't bother for manufacturing speed. I've noticed that the pre- crimped heavy cables people buy for car starter motors etc. often aren't soldered. You can sometimes only easily tell by removing the heat shrink on them & looking, Fuse indicator wise, I was thinking of a separate mounted little box with LED's in a row connected across each fuse with a resistor. More work , but if someone was starting from scratch, the thin wires to the LED box could go in the same crimp connectors .Should indicate if a dud battery blew a fuse with a shorted cell. Enough voltage difference to light an LED. I don't think shorted cells are that common for lead acid batteries, but it does happen. A 10v or so faulty battery with the higher 12V + ( 14 v+ on charging,) common line, should light an LED.Your 3 D printing is great . I wish I had one.
That looks a lot better.
+Spikey DaPikey Thank you.
I don't think it is over Ingineered at all. In fact I love it, you did a really great job.
I think you should start making and selling them. LOL. Seriously though I do think that would be something to think about. I would buy one or two for sure!
+charles howard Cheers - not sure I want to start manufacturing them really, the time it takes means a low return. You'll have to get yourself a 3D printer. Once you do you find there's all kinds of things you want to improve! :-)
Thanks I didn't think of that part of it. Oh well good Job anyway.
Nicely done, Adam. You might find that the batteries are taking/delivering slightly different currents because of various factors. There will also be some current flow from one battery to another. These things are inevitable, but you've done what you reasonably can to minimise future problems. As for the tight spacing, maybe Aluminium plates between batteries, a radiator, and even a cooling fan could be used when under high load or high ambient temperatures. If you're not pushing them hard, the batteries should be fine as-is. They have far harder lives in cars!
A very good point - engine bay temps can get quite high (and pretty low too)!
Aluminium plates is a nice idea - I'd just need to make sure they were clear of the terminals. My batteries tend not to be under very high loads at all and you must remember, I live in England - high temperatures aren't all that frequent either! Cheers
Hi Adam i know it's a old video but perfect work. Current flow between batteries would be ideal hence balancing. Plans for my future powerwall thinking of going lipo4 100amp cells. Just starting now on building 18650 mppt 100w solar for shed power so your video's have been brilliant thanks. In progres of building ebike aswell.
Any mppt solar chargers that will work with a dc wind turbin 120w 10 amp.
Cheers thanks
excellent!
Cheers!
I saw once on youtube that these blade fuses can melt if the current drawn through them is close to their rated current.
+Arnþór Gíslason Its typical for a fuse the get hot and the surrounding metal will always serve as a heat sink (that's why fuses always blow in the centre) but I'm running these at fairly low currents. My battery bank breaker is 63 amps and that's to accommodate an over current situation on my inverter (it can handle twice it's rating for a few seconds) but if I draw much more than 40 amps for a while it will cut out. I expect these fuses will never see their full rating for more than a couple of seconds.
Thanks though - i'I'll keep an eye on them when I'm pushing my inverter.
Great one I like it I did something similar to the 24-volt bank I got in the house but this is great I'll do that in the garage since I had 4 12-volt batteries in parallel and the middle one died and drained the outer to
Wow perfect build on that , Looks great
Thanks Mike.
@@AdamWelchUK on a mt 50 tracker is there a way to change the date of the the boost and equalization ???
Really neat setup, great video, thank you sir.
I enjoy your videos, Adam. You are subtly hilarious.
Good rebuild! Thanks.
WE LIKE THE SET UP!! NEVER TOO MUCH, JUST SAYING OLD ONE LEGGED JOSEPH T RETIRED NAVY
Nice one. I like that setup!
Hi Adam. Thank you for your very Informative video's. It has been a Grait help..
Koodos! Now ya just need to make another 3D printed part: a cap to cover the whole strip so nothing "accidentally" touches both bars at once. Which would only happen when you're in there doing some kind of maintenance. Unless you wanna do like Pete did and make sparkles :P
And, of course, it's sunny when you can't use it, and raining when you need the sun :)
Neat. I see many battery banks (videos) of guys fusing each string and/or battery in their respective banks. When I re-did mine (a few months ago) I added one ANL fuse (200-amp) for the cable going to the busbar (Blue Sea Systems) and then up to the main DC disconnect. I did a recent video on this. I am wondering if I should fuse each string? Fusing each battery would get awfully expensive. Thanks...your shed system looks good.
Cheers Chris. The worry is if one string fails for some reason or if you create a short across one string the other strings can also deliver current in that direction if the strings aren't individually protected. My system is quite a bit smaller than yours - and it has considerably less current to deal with so individual battery fuses isn't so much of a cost issue for me. For your setup I think it is worth considering a fuse on each string (I think you have three?) for piece of mind.
Hi Chris, Adam's done a terrific job fusing 17 AH batteries. I have over 35 large (around 100 AH) batteries feeding inverters up to 3 kilowatts. I thought about lots of fuses, but decided against it. The trouble is, at high currents the fuses/ holders, cable & crimp terminals, all cause voltage drops & imbalance. This only gets worse with age, as the contacts tarnish etc. Switch contacts, circuit breakers, they all suffer from it , plus of course the bolts can loosen with time. Even without the vibration you get in a vehicle, terminal bolts somehow still can sometimes need re- tightening, even on a static battery system. I personally wouldn't individually fuse the batteries on a 200 amp or so system. It's just more to give trouble. Smartgauge on the Net has interesting stuff on parallel battery Imbalance.Even with cable of 30mm sq or thicker , his results are surprizing. Cheers.
hey adam you can drop the gauge wire down as well because of load share tie your batteries in pairs instead of singles but do the same and keep the cables the same length. Keep in mind as well path of least resistance the point where the batteries as closer to the inverter those batteries will be drained first and the farthest will play alot of catch up under high loads. Also the first to get drained is the first to get charged and also the first to fail.
Thank you ADAM
It isn't fun unless it's massively overly engineered.
I use flattened legnths of copper plumbing for my buss bars. Make friends with your local plumber and you can probably get more 1'+/- cast offs than you could ever use. If you really wanted to be finicky about it one end of the lead could be soldered right into holes you drilled.
Great work Adam!
Nice update.
Thanks for sharing your information. Joe
Hi Adam, I am a new subscriber looking into your old videos. The wiring seems to be small if you have an inverter but is that because each battery is now going through the busbar?
Yeah, with the batteries in parallel each one was delivering only a small amount of current which adds up to to a much larger current on the bus bar and the main positive and negative cables. Each battery was fused at 10amps if I remember correctly giving around 80amps available for an inverter.
Thanks, has it panned out well over the years doing it that way. Clearly it would be cheaper to start from scratch that way.
I am trying to build a lead acid balancing circuit using a dedicated SMD chip. Might be over kill for this, but I will try and find the info on the chip and post. We are using it to try and extend the life of a 36v battery setup 6x6v golf cart batteries
Sounds like an interesting project - cheers.
Oww, and did you sand the surface of the bar before screwing the terminals on? Allu likes to form a nice oxidation layer :s Or if you want to make it real fancy (and have a new project :D ) copper plate the bars with electroplating :D
+tengelgeer I did yes - forgot to mention that didn't I?
tengelgeer sanding and then using an anti-oxidant compound may be another option. Good thinking. May not be a huge deal on the smaller lead, but the main lead yes.
+tengelgeer, Bare Aluminium, when exposed in a Nitrogen atmosphere, has a beautiful pale yellow colour. When Oxygen contacts it, an oxide layer forms instantly, giving it the greyish-silver colour we are familiar with. Roughing the surface just gives more surface area on which that oxide will form. A good pressure contact will cut through most of the layer, and allow a decent electrical connection as the metal partly welds to it's connector. Aluminium is a very strange metal, which has a continuously moving surface when viewed under an electron microscope. And it also migrates when current flows through it. In one of my jobs, in the 1970's, we used ultrasound to weld Aluminium wires to transistor surfaces. NASA are using the same phenomenon on a macro scale for what they now call 'friction stir welding'.
+RWBHere You're right, better to use some sort of anti-oxudation layer :)
@Adam, time to copper plate? :D :D :D
The issue with this new configuration is that each battery will never have identical impedances, therefore during high load discharge it is possible for more current to be supplied by one of the batteries than the others, additional this may also cause the fuse from the battery to fail.
Thanks - I'll watch out for this.
I wonder if you could compensate for this - the difference is going to be a fraction of an ohm. If you get all the batteries to an equal full charge you can measure the internal resistance of each and make up a length of wire per battery to compensate.
The trouble with Aluminium is that contrary to popular belief, it is actually really quite reactive and quickly forms an air tight, insulating oxide layer within seconds and your connection will deteriorate over time unless it is correctly sealed (i.e soldered or electroplated). That's why copper coated aluminium cable is such a problem. Squashed 15mm copper plumbing pipe would be a better option than that Al bar.
+ben hunter I'll keep an eye on it. Wouldn't be the be of the world if I need to replace it with some copper. Perhaps I shouldn't have been so cheap.
Kudos on making it look so neat though. Very nice.
+ben hunter Cheers
Adam, please see my response to tengelgeer. A good tight screw terminal will partly weld Aluminium to other metals. As long as the connection is kept dry and salt or acid-free, you should not have too much trouble for a long time. Once you encounter moisture, coupled with a salt or acid (or metals such as Mercury or Gallium), the contact will deteriorate rapidly.
That sounds plausible, as long as you get enough torque , and therefore mounting pressure on your fastener.
Where do you get your bolts from? i've tried a few local diy places and couldn't find any. I built a wind turbine recently which needed lots of different sizes/lengths and it was a chew on buying bolts so had to get a kit from Amazon although not the cheapest. Like the design and kudos for designing your own kit!
Cheers Colin. The bolts were m5 16mm Cap Screws from Toolstation (item 29995) and I used their m5 nuts too. I've one not too far form me but it's free delivery if you spend £10 anyway. I'm accumulating a decent biscuit tin of various sizes and lengths of bolt now from various projects and using the why buy one, buy many philosophy!
Hi Colin, yes Toolstation is great. Another good place for all sorts from connectors to hardware & semiconductors etc. is CPC Plc (Preston). You only have to spend £5 (ex VAT) online for free postage . I have one of their catalogues & it's A4 about 2 inches thick!
nice build but the smaller wires is not a good idea for higher amp drains.
I had the idea of giving each battery a chunky MOSFET or several on the negative, gate pulled down with a high-value resistor, and pulled up by a piece of thin wire running taut around the battery.
Why? Because lead-acid batteries do fail, and when they fail they often fail in such a way as to swell slightly. Swelling that would snap the wire wrap, turning off the MOSFET and effectively isolating the battery so that its demise cannot damage any other batteries.
Neat trick but would a small amount of swelling be enough to snap the wire?
***** If you used a single small strand of copper, or if you only clipped it at one end so it would pull loose easily, I imagine so.
Very neat Adam! :)
Is a power inverter just for lights . It could have just as easily use 12 volt LEDs
Hey Adam, can you please make a Fade-in Fade-out LED (Strip) Dimmer and sell the kit on your site or put an affiliate link so we can buy the parts? THANKS!!!
Great project :) One thing, as all the batteries are in parallel how will you know if a fuse has blown ?
+Zen Zen That's a good point. A few ways I can think of. Open the fuse holders up and try to look from the top - might be a little tricky to see. Grab my multimeter and check continuity between the negative bus bar and each battery negative terminal. Or finally run a load and use my dc clamp meter around each batteries wire to check that each battery is delivering some current. There might be some improvement to make here - thanks.
Would be nice if you could somehow rig up a resistor/LED arrangement across each fuse as an indicator to show if it has blown. I've seen this on equipment many moons ago so I'll do some digging :)
Various circuits around for this on a Google search, some better than others, but the easiest thing I've found are blade fuses with a built in LED that lights up when the fuse has blown :) You would then just need to drill a little hole in the fuse cover so that you can see it easily. www.autoelectricsupplies.co.uk/product/854/category/157
Yes , that's what I was thinking & suggested before I noticed your comment. Sometimes you get a faulty fuse or holder. Be a shame to damage a good battery by not realizing that it was not being charged & got sulphated, just for a fuse.
I wonder if the resistor in the lighting up blade fuses would be low enough to make it light in this set up? There'd only be the voltage difference between the bad battery /good battery line. Probably only 2-4 volts in most cases, a bit different to most applications where the fuses are connected to just one 12v battery.
Oh, was it based on my comment about star configuration i use?
Decent video at all... Adam did you wonder about temperature sensor to each battery and INA219 sensor to each negative battery connection? I think that it could be interesting for few pounds... :-) don't you think?
+LWQ LWQ Yeah - that is an interesting idea... ;-)
Adam Welch - and also you can add a relay to each battery to switch off battery that is working somehow strange automatically... :-) and next idea - I would recommend to use copper bars, aluminium is going to sneak away from compressed connection over time. And the last one - I would consider to make a battery box out of Fermacell boards. This material is fire resistant and quite cheap...
+LWQ LWQ Thanks again. Yes - a battery box is on the list.
Yea, short Bus Bar is the means. Utilizing Aluminum somewhat defeated the purpose. LOL I use Aluminum Bar like that with little to NO ISSUES. Not quite as conductive as Copper but using over size corrects that issue. CHEAP ! Employ Conductive Adhesive used for Auto Window Heater Elements insures electrical Bond for years.
I have golf cart batts. in series. for 24v. it helps the inverter efficiency. but now I need buck converters for my 12v led lights. any advice for a good cheap buck converter that will last. I have about 10 16' led tape strips. and 4 are RGB. so I need about 30-40amps at 12v. I would like the most efficient design. or I may as well use my inverter. I also have a low voltage relay on mind. at 30 amps 24v. to shut off at 22v. use this with a 30 amp or multiple 10amp units. what ever is most efficient . power consumption wise. great videos very inspiring. makes me want to finish my off grid home. and move.
I pretty much tested this exact thing a little while ago - although not to the level of current you are thinking about. If you use a load output of a solar charge controller that should give you the low voltage disconnect you require. ua-cam.com/video/dZHuj3R-g9A/v-deo.html
Looks like you have enough room to put a cable on each end, of each buss bar, and combine them at inverter(?)
I did leave room for expansion, but my inverter does come off the main cable. It’s protected by a breaker - or two.
the buss bars look store bought. and looks great. if you only had brass or copper. but what ever works.
Thanks - they are holding up well so far.
where did you get your batteries from I have two the same but would like to get more without pay lots of money
+mark smith They were taken from UPS's which were undergoing routine maintenance. They were due to be scrapped until I saved them.
I got mine out of car booster packs but waiting for more to come along so I can increase on amps aa there are only 20 amps each
That's awesome, would you care to share your 3D printer files for those items?
I guess I could - I thought they were a bit bespoke and people might find it easy enough to make their own. Guess I should - hang on.
Your wish is my command... admw.uk/jG :-)
THANKS!! These are great!
Hi, enjoyed the vid a lot. Just a question, does having the main output wires at opposite ends of a busbar make any difference?
Thank you. The quick answer is yes, but probably relatively small. You take the main positive and negative at opposite ends of the string to even out the load. If you took both from the same end the first battery would deliver the most current, with the second delivering the second most etc. etc. The last battery in the string would in theory remain the least discharged, but also the least charged - so ultimately lowest cycles. Now in reality, it will probably feed its current into the next battery up, as will that one - so left to sit for a while they'll all become pretty even again. Although for current to flow there has to be a potential difference - so one battery must be higher than another.
As I said ideally you connect all batteries to the same bolt to reduce the increased resistance between each leg in the ladder. Sadly that's really messy and not always possible, so I went for the second most ideal option I could come up with.
Hi Philip,it won't make much difference with smaller batteries like Adams .According to Smargauge, this sort of thing makes a huge difference with several large (N.B. say,100 A.H batteries) wired in parallel for big inverters. In one instance one battery delivered twice the current to another according to this guy for one (bad) method of wiring. I still find it hard to believe that It's THAT bad, but Smartgauge say they've done proper tests & it really is, even with thick cable etc. cheers.
As much as I like your setup and I really do, I would at least change the nuts, washers, fuses and bolts to copper because the current is only as good as the weakest link, which in this case would be the connectors at the end of each wire and the nuts and bolts... Why worry about all of this copper if the connections is of inferior metals? I have the same setup as you showed when you had them stacked where you thought you were running out of space... I have 2 holes drilled thru a piece of wood long and thick copper bolt, my buss bars and I added copper washers between the copper connectors with a copper washer and a copper nut at the end. The copper washers between each of the incoming wires spaces it just enough so there's no issues of overlapping each connector. My fuses are even copper and connect to copper holders. I have batteries on each side with my copper bolt "buss bars" in the middle of the of the two sets of batteries. I repair computers so I'm not perfect, but it boils down to common sense. I have people that bring in electronics with various connections like USB and 3.5mm headphone jacks and they have cables coated with gold and I explain the USB and most 3.5mm jack are almost just regular metal and a magnet sticks to the connectors most of the time so the quality ends there, I know the connectors you're using here is not magnetically conductive, but of cheap metal and does no justice to your hard work.
MrBrymstond as an industrial electrician I have built systems that carry thousands of amps, and the bolts (specced by engineers) are always mild steel, as copper or brass do not have enough tensile strength. the important part of an electrical connection, as in this setup, is the connector to the bus bar. The bolt should carry no current.
Here in Australia, it is in breach of the wiring wiring rules for a connecting device (I.e. a bolt) to form part of a current carrying system.
Your comments regarding computers/audio is totally different. You are talking about signal level (Or radio frequency transmission) and connectors are always the weakest link, therefore should be of the highest quality.
Cheap tin does not carry the amperage as well as copper, nickel, lead, silver or gold or why would you worry so much about the bus bar and the nickel strips on lithium batteries? The quality stops at the weakest point, tin.
Interesting video. What size cable did you use for the new battery connections?
Thanks. It's AWG14.
So about about 2.0mm2
+urbanimage Yeah. Pretty much.
i just did a very similar setup using the next size down in batteries, I have 2 banks so far both containing 6 batteries each. I have the charging off a solar panel in conjunction with a car battery that is charged from a separate panel. I have only just finished the setup and only visit the property occasionally so im yet to test. Is the idea that this will hold greater power than a single car battery? I did this because the batteries were free so I wouldn't have thought to do this otherwise. Is there a benefit to separate cells in this format or would the ideal setup be a deep cell truck battery or li-Po battery?
Note - Old alarm systems are a great place to get the small lead 12V batteries cheap or for free if your lucky. they are always kept charged and only the highest quality is used, however replaced in the new system so alarm companies have tones of them.
I have been given 2 batteries built from 84 LG Chem 60 amp hour pouches configured as 14s3p
I want to keep them in tip top condition until they get connected as a household powerwall.
Something like this would slowly charge them, but should I take them to say 70% charged and every so often check them, or charge them to say 47 volts and have them discharging through a small load down to say 42 volts then repeat, and how big a load should I use? I was thinking a couple of 24volt bulbs in series.
I also have some configured as 3s4p that need looking after.
I need a bigger shed
We all need bigger sheds Roger! If you are storing your lithium cells for long periods it’s best to charge them to a mid cycle storage voltage (for example I’d go for about 3.8 volts for lithium ion). That’s how most new electronics are delivered and stored. This will also allow you to see after a few months of any of the cells are self discharging more than any other.
Cycling your cells, even only lightly will reduce their service life. It’s a chemical reaction after all and the process can’t go on forever.
The negative and the positive main leads should be in the middle of each corresponding bus bar, instead of at either end.
So that the batteries will charge evenly.
I'm not sure that is true if you think about the resistance. Battery one is close to the main positive so has a low resistance with respect to it's neighbors, but the highest resistance on the negative with respect to its neighbors. Moving down the string that ratio changes , but overall the total resistance per battery should be roughly the same. Corner to corner connecting is pretty standard and generally seen as the easiest method to ensure even drain.
Adam Welch I thought that an even length between each battery and the main negative and positive leads would ensure same amount of distance between each battery and the main lug...
Kind of like a Hammock between two trees the negative and positive leads fan out into the middle of the Hamic with multiple lines so that the batteries are along those lines and even length.
My opinion...
are those smf vrla batteries?? what is the capacity of a single battery??
Yeah they are 17Ah a piece. Recycled UPS batteries all of the same age and use.
I'm i right in assuming you have approx. 800W usable wattage?
Nice! Looks really good! But is it just my OCD that finds it ridiculous annoying the spacing of the holes is different... Especially because it would have been an easy fix by just drilling the holes of both bars at the same time by stacking them....
+tengelgeer Thanks. They were drilled offset to try and space the positives and negatives a little and to give the space required for the larger main crimp. Not sure it worked though.
Ahh, then it's just me :p
awesome!
Uhm.. that's not how batteries works. If you have 6 batteries in parallel, no mater what point you connect the load, the load across the batteries will be equal/the same. Same goes with charging, if they are in parallel, all the batteries will receive the same amount of charge, and they will equalize given a little time. No amount of fusing will change that. If you connect 1 low battery in a bank of 6, the other 5 will discharge into the 1 low one until all reach the same voltage/level of charge. If you have a shorted out battery in your pack.. all 6 will drain to the same level as that one. That's why you should only use 1 type of battery in a pack, never mix batteries of different type or age. You can mix batteries of varying capacity with no issues. But they have to be the same type.
Hallo adam i like your video but in this case this is not save suppose there is a Mouse don 't dak where she com from but belief me she going touch your two bars and then bang You have a dead Mouse make between the two bars 50 cm and put direct after the fuse a switch That can break the red and the black wire now You can change one battery safely
That really isn't an issue for a 12v dc system. I can touch both buss bars at the same time without getting any type of shock. I don't believe a mouse is anymore conductive than my finger.
The batteries being right up against each other is absolutely fine. if your having trouble with high battery temp you have charger issues or bad cells in one or several batteries. the biggest problem i see is your wire is way to small and too long. your losing efficiancy ...
300A/H battery 6
Tell us, how many fuses you need over the year ;-)
+CaroMan I will. Running count is eight :-)
Yes over engineered but better to be safe then sorry. Of coarse it will most likely change again lol.
+old time engineer True. We like to change and improve don't we :-)
could have threaded the bus bar instead of the nut brackets :D
+Flo I did consider this but my tapping set seems to be absolutely rubbish. The nut brackets are a bit silly but I was very pleased they worked so well. Cheers
But allu isn't that strong... Easy to strip the thread if you over tight them.
I feel like you could have just taped those holes
Quite possibly, but I haven’t done that before with any success!
For aluminum and thin steel I have been using those drill bit and tap in one they break on thick steel but softer metals are fine
Cheers. I might get myself some.
Try again. That parallel way you re-did Is still not the best way to balance your batt.
I think it's insanely over engineered. If some bloke ask you to use a BMS tell him to piss off. Your setup was fine the way it was. Now, if we were talking 18650's ? Well, I might agree as they can explode!
I quite enjoyed putting it together actually :-)
Over done and unnecessary, semi trucks have 4 really large batteries wired the way you had them at first. We don't have many, if any problems.
Copper pipe
your red looks like orange.
if you want to make like adam you should to pay 10.000 USD just for 3D printer
and 300 USD for the battery and many thing
why you don`t call the super hero to make a Miracle battery bank for you !!