i rebuild battery packs as a hobby. usually when the charger says it's full but it isnt is a very unbalanced cell. it needs opened up and each cell charged to an equal voltage, then put on charger. any set that wont go above 3v is not a good cell(s) and needs replaced with an equal capacity/internal resistance of the existing cells. for tool batteries i usually salvage from another dead battery to keep the brand and usage roughly the same if i can.
whats your take on these small buissness that are rebuilding car batteries at a fraction of a price? will they last as long as new ones? or you get what you paid for ?
@@mikeallen3646. It's hard to be the first customer but a reputable remanufacturing company is correct about the concept. Electric Cars should ALSO have swappable batteries (pull into a single car wash size building, robot swap the battery in the same amount of time as filling up a gasoline car) but they weren't interested in the maintenance, cost, etc.
@@arcanondrum6543 Tesla prior to its initial release actually had that as an option, swapping out the whole battery pack. For whatever reason it never came to fruition.
There’s one Chinese company which is doing that - it requires building the net of these service-points ofcourse which takes cost and time. I heard They’re trying this also in Europe, probably United Kingdom and also there was something similar in Sweden/netherlands I believe.
Good information. I have this issue after putting one of my batteries in my kids 4wheeler. It ran great for a while but won’t change. I tried to manually charge it but that didn’t work. It makes sense that Jerry rigging it into the four wheeler may have discharged one of the cells lower than the rest. I use to build battery packs when I raced RC cars, I’ll pull this one open and check the cells. I still have a bunch of hobby grade chargers, and one that will do lithium. Are these usually 18650’s
Here's my method. Send the thing into MW using e-service. They provide a prepaid label. Then in about a week they'll send you a new one in the blister pack and everything. If you don't have proof of purchase they'll go by the manufacture date however in my exp, even if it's out of warranty, you're getting a new one.
Wow ! Please read up on lithium batteries and how there made , this is fooling no one yourself. That bms shut down that battery for a reason an most of the time but not always the cells are out balance, all it takes is one parallel cell or group to drop under 2.5volts to trigger the shutdown you can have all the other cells full at 4.2v but one group to low shuts it off because the charger will keep charging till top voltage is met that means some cells will over charge and that my friend is where lithium fires come from . So read more on how and why before you burn down your home or shop
Elegant answer. Have had the same issue with a Greenworks battery and using what was at hand did it this way: Put a paper clip in the positive and one in the negative battery ports. Then using two low-voltage wires with alligator clips on each end attached a 12V battery tender to the Greenworks battery. This time connecting positive to positive and negative to negative. Plugged in the tender and let it run for 15-20 minutes and voilà the Greenworks battery charger will now recharge your battery. Best to avoid this situation by not running your battery so low before recharging.
All you are doing is circumventing the testing circuit the charger does that would indicate to it that a cell may be bad or shorted. It is set up to not charge a pack under a certain threshold. Using any dc supply equivalent to the battery's output will achieve what you did. I worked for Snap-on Tools in the repair center here in Harrisburg for 20 years, and this is how the chargers work and this was the method we used for our shop batteries. lithium Ion packs use balance charging, so each cell has to charge and discharge at the same rate. One bad cell can drop the entire pack.
Nice hack! But I would have cleaned the contacts first then try the charger again before "marrying" them with the utility knife blades, just a thought.
@@diyhvacguy I did watch the whole video, but you didn't indicate if you tried to charge the battery again AFTER cleaning the contacts and BEFORE the knife blade trick, as you know, sometimes that's all it needs
If you just used the battery and ran it for a long period sometimes the battery may be too hot internally to accept a charge, most all have a thermistor for overheat/low temp protection. After using a bettery its a good idea to set it out and let it cool or maybe even place it where it is a dry and cool place for 30 minutes to an hour and then try again to recharge it.
Similar to tricking any BMS type battery and also Inverters that won’t charge a system if it’s below 10.5v For auto batteries and the like that a charger says is dead, just use jumper cables to a good battery with a trickle charger. Use another set of cables from the good battery to the bad battery. Twenty minutes and remove all cables. Attach the charger to the bad battery and viola. The razor blade trick is cool. One note, the “bad” batteries will revive but eventually you will have to recycle them.
This is a problem only if you allow your battery to discharge completely under load or leave it sit too long. I have used this solution on AA rechargeables using paper clips. Most rechargeable batteries slowly self discharge so top them off occasionally.
My question is would you get the same effect if you cleaned off the bad battery and put it back on the charger as opposed to syncing up with another battery?
While cleaning the contacts is important I'd be concerned about using sand paper. It's very aggressive and will likely remove the plating. Works short term but eventually will result in corrosion.
I'd splurge and buy a sheet of 3M Wet-or-Dry sandpaper. Instead of using cheap sand grit, the grit is bonded to the paper. If you get 800-2000 grit, that's so smooth you are just polishing, not scratching. You can get small assortments up to 3000 grit in auto body repair shops or aisles.
Hmm I seen dewalt videos with the same trick bit they only connected the two for like 10 seconds. And when I did it the battery got worse lol. It would only charge one bar before and now won't charge at all.
It's my experience that Lithium Polymer (LiPo) batts have a default nominal voltage of 3.7V/cell and the typical batteries used in tools use Lithium Ion (Lion) at a nominal voltage of 3.6V/cell.
This works…….sometimes. I’ve had that work and I’ve had it not work. I had one battery that you could do that for long enough that it would show two bars just from being hooked to another battery. It would run a tool. But if you put it on a charger it would not charge. Red and green light would blink back and forth.
One of my M18 batteries will only charge up to 3 bars on the battery, but NOT to the 4th red bar! Does anybody know how to fix that issue, please? Thanks for this video!
While this CAN work, there is a reason the battery management system won't allow the battery to charge. Usually you have a bad cell in your pack. This will not address that. You may find that it charges but can't handle high loads, or dies in a fraction of the time it used to run a tool. Not sure how robust the safety circuitry is on these packs, but lithium cells do NOT handle over charging well AT ALL, with fiery, explosive results in some cases. Don't ask me how I know this...... You would be wise to send the pack in for replacement or to a battery shop for repair. A bad cell can be replaced with on of identical capacity, internal resistance and voltage for a permanent, proper repair.
I wonder if there’s a time charging circuit in these batteries meaning after so many cycles it just says yeah no we’re done and then force you to go buy a new one
I have a Variable output DC power supply and patch cables. So should I put around 20VDC into my dead 18 volt Milwaukee battery? At what amperage rating?
The problem is the internal Battery Management System (BMS) of the battery shutting down and not allowing the charger to charge the battery because the total voltage of the battery is Below a Safe level due to 1or more cells being low. By jumping the battery with a 2nd fully charged battery for a while... the low cells will be slightly high enough for the BMS to allow the charger to work,
@@theapocilip BMSs are there to protect against Lithium (Li-Po, Li-Ion) battery Overcharge and Under Discharge to protect the batteries. I have a $4K quadcopter that has BMS protected Li-Po Smart Batteries that discharge over a too long time.. When the batts discharge too low for the charger to recharge them, I force charge them to bring the batts back over the Minimum so the Balance Charger works properly. Discharging Li-Po batteries below or above their safe level can damage the batteries over time. Goggle is your friend....😉
Why isn't the BMS designed to allow the most-depleted cell(s) to recharge first... postponing the charging of any cells that have a higher voltage than the minimum cells have?
So, would any "dumb" source of low DC voltage work, if we don't have a healthy identical model battery? What's the range of voltages that could be used to "kick" the dead battery?
I've actually used a 12V car battery charger before to "jump" a dead drill battery and get it to start charging normally on its own charger. Wouldn't suggest anyone try this, but I did, and it worked.
Yes. Dumb DC voltage at or under the batteries rated voltage. Don't over volt them. Just enough to get the BMS over its low threshold should do it. It's not advertised what that low threshold is so this method is good. If you do use another source, just make sure you don't leave for an extended period.
@@zjan4me True. I should have clarified, in my statement above, that I only used that method by having one cable connected to the battery terminal, via a wire, and very quickly tapping the other clamp on the wire connected to the other battery terminal a few times. The idea that this was not a good idea and could possibly end badly was going thru my mind the entire time! LoL. Luckily, it didn't.
Just so it's under 20 volts it will work. Kinda depends on how long you want to sit there. I think with the method shown in this video, it doesn't matter too much if you leave it on for hours. There's not enough power in the other battery to "overcharge" the "dead" battery.
This is great but be aware that the brains of the charger are in the charging base, not inside the bat pack. Your explanation that the charger might be a "little confused" could be true, or it might be protecting you from a more serious issue with one of the cells. Just be mindful of the fact that without the charging circuitry there is a risk of thermal runaway. These aren't your grandpa's NiCd cells.
ya, i had gotten a set of drills and 2 batteries, but it never had the charger, and i couldn't find them for sale anywhere!, you can get whole set of drills batts and charger, you can get just batts (at absolutely insane $costs), so for years i had to manually charge them, worked for a long time, but eventually they got 'unhappy' and wouldn't work anymore, no matter if charged and at full voltage or not, g0d dam safety cut off, .. so i ended up modding both the packs and the drills, they both need it. to just always work NO MATTER WHAT. they can be on fire now spewing juices all over, and it will still run, under no circumstances what so ever will they EVER stop. i can run them down to 2 volts total per pack if i want to. of course i dont want to cuz that's not good for them, but in a emergency, i can. i hate it when there's still much charge left in any lion pack but the thing shuts off anyway. ya i know, them batts dont like going below a certain volt, what is it? 3.2-3.5v per cell, considered dead? with 3.7 normal, and i think 4-..1 full? either way, its my tool, and i wanna be able to use it how i want. i wouldn't do this to a new battery, but these pretty much stopped working cuz 'they' consider them dead and not to be used anymore anyway. so me doing ?able things to them to make them still work for any amount of time more is only a + in my book, so ya, everything is good now and I'm 95% happy with it. only downside i have is no more charge meter. but that's ok, i can tell by how it feels enough.
I'm no pro contractor and rely on channels like yours for help in a lot areas.. But I do know more than most about lithium ion and have built batteries 10x the size and power of these power tool packs.. And letting you know "reviving" batteries is a bad idea. In this scenario, one of the cells has lost more voltage than allowed by the bms. This type of thing happens all the time because not all cells age the same way. When that happens the low cell can react unpredictabily and begin to discharge by itself when the others in the pack are fine. That low cell can get even lower and with a little bad luck can go into thermal runaway and catch fire even if you just leave it on a shelf undisturbed.. If you hack a pack and revive it... You're only abusing one or more bad cells more and increasing the odds of things from going from bad to much worse.
I've been watching you channel for some time now but really recommending folks to "jump " their batteries? NO WAY! One little spark and now you could have a handful of flaming lithium battery with knife blades sticking out and no way to extinguish it? There's a reason the charger is not allowing the battery to charge! Possibly a bad (shorted) cell or unbalanced cells, possibly there was some moister intrusion and a damaged circuit board. Cell balance can be checked with a Milwaukee scan tool (not available to the public). Also there are a couple versions of Milwaukee chargers similar to the one you are using, some of the older chargers will not charge the newer batteries. And if you want to play "mad scientist" with the batteries at the very least wear safety glasses and gloves, and never ever leave the batteries and charger unattended and never on a flammable surface! By the way if in fact there is a shorted cell in one and you "plug" a good battery into the shorted battery it you can burn the fusible link up in the good battery! Is it really worth the chance?
You're saying that when you using a grinder throwing a shower of sparks I could blow up my battery. NOT! Your premise is that a spark caused by jumping the batteries in their factory enclosed covers would somehow ignite the cells inside that cover or some sort of mystery gas that doesn't occur on Lithium Cells. The only real danger might be if you shunt them backwards (short) or use an outside power source of much higher voltage. If you're uncomfortable don't do it. If you are, great way to save lots of money. In today's economy, every but counts.
One thing that I have experienced with my Milwaukee batteries from time to time I can put them on the charger and they will charge normally. Then again sometimes I can put one of them on the charger but for a second or two it’ll stay red like it’s charging and I go to walk away and it’ll start flashing red and green, like what does that mean?
Will you need to do this method with that same battery each time it drains? Why don't the chargers have a feature that revives them? Is this a scam to sell more batteries? Hmmm.
yeah buddy. you will learn through the years all of this stuff is thrown away when it comes right down to it. next thing you know the tool brand you invested all your hard earned money into will change the battery design and your old stuff will become obsolete. after all the goal of every corporation is to make as much money as they possibly can. your experience may vary. as long as you can keep making an income with use of your power tools I think thats what really matters. so you can afford the new stuff when the old stuff becomes obsolete.
Really. With a low voltage DC power source? You clearly don't know how this works. You can get burnt if you are touching the razor blades and they touch each other. But that is a burn, completely different than a shock.
I remember other comments on this guy’s channel from you ‘Chicago Cu-t’. I got you pegged as an a-hole! The question is: Why do you keep watching dude’s excellent channel if all you can do is be negative? Go douche somewhere else.
This procedure is extremely dangerous! It may (and mostly will) work well but you're playing with fire. You can easily burn down your shed, garage or house. I've seen close calls because of battery failures (including a laptop at my own house). This is nothing like jumpstarting a car! For lithium batteries connecting a full battery to an empty battery introduces a risk of fire or explosion because lithium batteries have a low internal resistance and can provide hundreds of amperes. If there's a significant imbalance you can easily overvolt a cell and cause a thermal event because you bypass the BMS (it does not control power but only communicates to the charger to tell it to shut off). I have revived dead or bad performing batteries but I open the case and connect a balance charger to the cells. This way there's no chance of overvolting a single cell and it properly balances the whole pack. This procedure still isn't considered safe by any means because you're tampering with a lithium battery but it's very useful to resurrect a bad performing battery. There might be an even better solution: Try to warranty the battery because you still might have warranty on your battery even if you think you don't.
you need to change the title of the video and take out the word ANY....this method did not work on my ridgid octane battery that was doing the same thing...its dead and will not recharge after trying this
Sorry, this won't revive a truly "dead" battery. What's actually happening is that the discharged battery isn't putting out enough voltage for the "smart" charger to think a battery has been plugged in. When the "dead" battery is connected to a "good" battery for a short period of time like this, and then put on the charger, it has the required voltage to put the charger in charge mode. If this doesn't work, then your battery is truly dead--recycle it, and buy a replacement.
There are numerous videos on YT with this info. It will only work with a good Li-Ion battery pack that has become discharged below the acceptable voltage determined by the battery management circuit board. Since around 2016 it seems the quality of these batteries has fallen off a cliff. An 18650 battery in good condition will read about 4.2 vdc. Being they are wired 2 in parallel and then in series, any issue will most likely involve 1 or more sets of batteries. I have had to replace as many as 6 out of 10 in one battery pack. They must be replaced with preferrably the same brand and amperage rating. Some of the batteries will fail "open" with No continuity and will never function properly until they have been replaced. Walk On ! ☺♥†♪♫ 11-16-24
This crap is why I do not own a single battery powered tool. My Grandpa's old drill is still working great, after several replacements of brushes and bearings. He bought it new during WW2 while he was building bombers for Boeing. My uncle uses it almost every day for something or another because he just loves the feel of that hefty metal drill in his hand and knows it won't stop until he reaches the end of his extension cord. These battery powered tools give up too easily. The batteries go all metric and that's just an added expense as long as you can till buy the same battery. Then after 10 r 15 years that battery gets obsoleted and the drill is useless. I would rather have a tool that will last 80 years and keep on going. Yeah I will be long dead by then but my grandkids will think I was a friggin hero for leaving behind a legacy of tools that don't end up in landfills. That's not to say that the average corded tool will last, but some will. Look for lots of steel and aluminum, not a lot of zymak and plastic. Look for "Made in USA" and not made in China. Costs more, worth more.
i rebuild battery packs as a hobby. usually when the charger says it's full but it isnt is a very unbalanced cell. it needs opened up and each cell charged to an equal voltage, then put on charger.
any set that wont go above 3v is not a good cell(s) and needs replaced with an equal capacity/internal resistance of the existing cells. for tool batteries i usually salvage from another dead battery to keep the brand and usage roughly the same if i can.
whats your take on these small buissness that are rebuilding car batteries at a fraction of a price? will they last as long as new ones? or you get what you paid for ?
@@mikeallen3646. It's hard to be the first customer but a reputable remanufacturing company is correct about the concept. Electric Cars should ALSO have swappable batteries (pull into a single car wash size building, robot swap the battery in the same amount of time as filling up a gasoline car) but they weren't interested in the maintenance, cost, etc.
@@arcanondrum6543 Tesla prior to its initial release actually had that as an option, swapping out the whole battery pack. For whatever reason it never came to fruition.
There’s one Chinese company which is doing that - it requires building the net of these service-points ofcourse which takes cost and time. I heard They’re trying this also in Europe, probably United Kingdom and also there was something similar in Sweden/netherlands I believe.
Good information. I have this issue after putting one of my batteries in my kids 4wheeler. It ran great for a while but won’t change. I tried to manually charge it but that didn’t work. It makes sense that Jerry rigging it into the four wheeler may have discharged one of the cells lower than the rest. I use to build battery packs when I raced RC cars, I’ll pull this one open and check the cells. I still have a bunch of hobby grade chargers, and one that will do lithium. Are these usually 18650’s
"Amazing trick! Reviving dead power tool batteries this quickly is a game-changer. Thanks for sharing this valuable tip!"
Here's my method. Send the thing into MW using e-service. They provide a prepaid label. Then in about a week they'll send you a new one in the blister pack and everything. If you don't have proof of purchase they'll go by the manufacture date however in my exp, even if it's out of warranty, you're getting a new one.
Just what I needed tonight
Damn, I wish I knew this as well.
Wow ! Please read up on lithium batteries and how there made , this is fooling no one yourself. That bms shut down that battery for a reason an most of the time but not always the cells are out balance, all it takes is one parallel cell or group to drop under 2.5volts to trigger the shutdown you can have all the other cells full at 4.2v but one group to low shuts it off because the charger will keep charging till top voltage is met that means some cells will over charge and that my friend is where lithium fires come from . So read more on how and why before you burn down your home or shop
Elegant answer. Have had the same issue with a Greenworks battery and using what was at hand did it this way: Put a paper clip in the positive and one in the negative battery ports. Then using two low-voltage wires with alligator clips on each end attached a 12V battery tender to the Greenworks battery. This time connecting positive to positive and negative to negative. Plugged in the tender and let it run for 15-20 minutes and voilà the Greenworks battery charger will now recharge your battery. Best to avoid this situation by not running your battery so low before recharging.
This is basically doing the same thing.
Yes, absolutely the same idea. Shared it in case someone doesn’t have a second battery and that paper clips can be used instead of scraper blades.
Yep contractor razor blades is the way I have been doing for a while, works great after few mins then to charger!! 🎉
All you are doing is circumventing the testing circuit the charger does that would indicate to it that a cell may be bad or shorted. It is set up to not charge a pack under a certain threshold. Using any dc supply equivalent to the battery's output will achieve what you did. I worked for Snap-on Tools in the repair center here in Harrisburg for 20 years, and this is how the chargers work and this was the method we used for our shop batteries. lithium Ion packs use balance charging, so each cell has to charge and discharge at the same rate. One bad cell can drop the entire pack.
This is a definite bookmark. Thanks.
How crazy my Dewalt battery happen to be like this 4hrs ago! I’ll try this in a few days! 🤞🙏Thank you!
Let us know either way please.
I love ❤ the razor blades idea for this. Thank you man 👍👍
I will try this as i have 3 scrap batteries many thanks
Did it work?
Nice hack! But I would have cleaned the contacts first then try the charger again before "marrying" them with the utility knife blades, just a thought.
You must have not watched the whole video haha we showed how to clean the contacts :)
@@diyhvacguy I did watch the whole video, but you didn't indicate if you tried to charge the battery again AFTER cleaning the contacts and BEFORE the knife blade trick, as you know, sometimes that's all it needs
@@GreyRockOne I understood your first comment.
@@canucanoe2861 uh..ok
If you just used the battery and ran it for a long period sometimes the battery may be too hot internally to accept a charge, most all have a thermistor for overheat/low temp protection. After using a bettery its a good idea to set it out and let it cool or maybe even place it where it is a dry and cool place for 30 minutes to an hour and then try again to recharge it.
Great pro tip👍
Similar to tricking any BMS type battery and also Inverters that won’t charge a system if it’s below 10.5v
For auto batteries and the like that a charger says is dead, just use jumper cables to a good battery with a trickle charger. Use another set of cables from the good battery to the bad battery.
Twenty minutes and remove all cables. Attach the charger to the bad battery and viola.
The razor blade trick is cool.
One note, the “bad” batteries will revive but eventually you will have to recycle them.
Cool 90-second video 😊
This is a problem only if you allow your battery to discharge completely under load or leave it sit too long. I have used this solution on AA rechargeables using paper clips. Most rechargeable batteries slowly self discharge so top them off occasionally.
My question is would you get the same effect if you cleaned off the bad battery and put it back on the charger as opposed to syncing up with another battery?
So you got 3 bars charged: does that mean it won't charge up to 4 bars? Or did you put it back on the charger and get it up to 4 bars?
While cleaning the contacts is important I'd be concerned about using sand paper. It's very aggressive and will likely remove the plating. Works short term but eventually will result in corrosion.
A Dollar bill will clean the contacts as well.
I'd splurge and buy a sheet of 3M Wet-or-Dry sandpaper. Instead of using cheap sand grit, the grit is bonded to the paper. If you get 800-2000 grit, that's so smooth you are just polishing, not scratching. You can get small assortments up to 3000 grit in auto body repair shops or aisles.
AWESOME IDEA !!! THANK YOU.
What are the other methods you speak of if this doesn't work?
I have a little battery like the pistol mag one that want even take a charge . Like the little battery in your video for any ideas
Thanks !
Hmm I seen dewalt videos with the same trick bit they only connected the two for like 10 seconds. And when I did it the battery got worse lol. It would only charge one bar before and now won't charge at all.
Aren't those battery packs full of the 3.7 volt batteries and is it usually a couple of those batteries that have low cells?
It's my experience that Lithium Polymer (LiPo) batts have a default nominal voltage of 3.7V/cell and the typical batteries used in tools use Lithium Ion (Lion) at a nominal voltage of 3.6V/cell.
I’m going to check my batteries now, thanks.
You never use abrasive on terminal contact points, that ruins them.
The burning question, is will it go on to function normally after that, or is it on its last legs?
Thanks
This works…….sometimes. I’ve had that work and I’ve had it not work. I had one battery that you could do that for long enough that it would show two bars just from being hooked to another battery. It would run a tool. But if you put it on a charger it would not charge. Red and green light would blink back and forth.
I. wonder if the idea works with blood transfusions.
Very cool
Remove the loose sandpaper grit from the contacts after cleaning them.
Would this same process be followed for a 60 volt battery?
One of my M18 batteries will only charge up to 3 bars on the battery, but NOT to the 4th red bar! Does anybody know how to fix that issue, please? Thanks for this video!
While this CAN work, there is a reason the battery management system won't allow the battery to charge. Usually you have a bad cell in your pack. This will not address that. You may find that it charges but can't handle high loads, or dies in a fraction of the time it used to run a tool. Not sure how robust the safety circuitry is on these packs, but lithium cells do NOT handle over charging well AT ALL, with fiery, explosive results in some cases. Don't ask me how I know this...... You would be wise to send the pack in for replacement or to a battery shop for repair. A bad cell can be replaced with on of identical capacity, internal resistance and voltage for a permanent, proper repair.
I wonder if there’s a time charging circuit in these batteries meaning after so many cycles it just says yeah no we’re done and then force you to go buy a new one
I have a Variable output DC power supply and patch cables. So should I put around 20VDC into my dead 18 volt Milwaukee battery? At what amperage rating?
Thank you! 👍
The problem is the internal Battery Management System (BMS) of the battery shutting down and not allowing the charger to charge the battery because the total voltage of the battery is Below a Safe level due to 1or more cells being low. By jumping the battery with a 2nd fully charged battery for a while... the low cells will be slightly high enough for the BMS to allow the charger to work,
Interesting I did not know that. but what makes a low cell so not safe that they need this BMS safety system in place. Or is it just for more profit?
@@theapocilip BMSs are there to protect against Lithium (Li-Po, Li-Ion) battery Overcharge and Under Discharge to protect the batteries.
I have a $4K quadcopter that has BMS protected Li-Po Smart Batteries that discharge over a too long time.. When the batts discharge too low for the charger to recharge them, I force charge them to bring the batts back over the Minimum so the Balance Charger works properly. Discharging Li-Po batteries below or above their safe level can damage the batteries over time.
Goggle is your friend....😉
Why isn't the BMS designed to allow the most-depleted cell(s) to recharge first... postponing the charging of any cells that have a higher voltage than the minimum cells have?
@@brothermine2292 better ones have cell balancers to keep them all equal.
@@theapocilip
Lithium ion batteries are very dangerous without a BMS to control voltage.
That's NOT A RAZOR BLADE. It is a utility knife blade, often called a Stanley knife blade.
Cool story
So, would any "dumb" source of low DC voltage work, if we don't have a healthy identical model battery? What's the range of voltages that could be used to "kick" the dead battery?
Was thinking the same thing. ie, some 18V DC power adapter
I've actually used a 12V car battery charger before to "jump" a dead drill battery and get it to start charging normally on its own charger. Wouldn't suggest anyone try this, but I did, and it worked.
Yes. Dumb DC voltage at or under the batteries rated voltage. Don't over volt them. Just enough to get the BMS over its low threshold should do it. It's not advertised what that low threshold is so this method is good. If you do use another source, just make sure you don't leave for an extended period.
@@zjan4me True. I should have clarified, in my statement above, that I only used that method by having one cable connected to the battery terminal, via a wire, and very quickly tapping the other clamp on the wire connected to the other battery terminal a few times. The idea that this was not a good idea and could possibly end badly was going thru my mind the entire time! LoL. Luckily, it didn't.
Just so it's under 20 volts it will work. Kinda depends on how long you want to sit there. I think with the method shown in this video, it doesn't matter too much if you leave it on for hours. There's not enough power in the other battery to "overcharge" the "dead" battery.
Planned Obsolescence at work
This is great but be aware that the brains of the charger are in the charging base, not inside the bat pack. Your explanation that the charger might be a "little confused" could be true, or it might be protecting you from a more serious issue with one of the cells. Just be mindful of the fact that without the charging circuitry there is a risk of thermal runaway. These aren't your grandpa's NiCd cells.
1:40 *Info starts here.*
The Milwaukee 9ah batteries were problematic.
Martial law that will never end, just like the TSA
This doesn't always work. I tried this method and it failed. I opened up the battery and noticed that one of the cells had leaked.
If i only had two !
ya, i had gotten a set of drills and 2 batteries, but it never had the charger, and i couldn't find them for sale anywhere!, you can get whole set of drills batts and charger, you can get just batts (at absolutely insane $costs), so for years i had to manually charge them, worked for a long time, but eventually they got 'unhappy' and wouldn't work anymore, no matter if charged and at full voltage or not, g0d dam safety cut off, .. so i ended up modding both the packs and the drills, they both need it. to just always work NO MATTER WHAT. they can be on fire now spewing juices all over, and it will still run, under no circumstances what so ever will they EVER stop. i can run them down to 2 volts total per pack if i want to. of course i dont want to cuz that's not good for them, but in a emergency, i can. i hate it when there's still much charge left in any lion pack but the thing shuts off anyway. ya i know, them batts dont like going below a certain volt, what is it? 3.2-3.5v per cell, considered dead? with 3.7 normal, and i think 4-..1 full? either way, its my tool, and i wanna be able to use it how i want. i wouldn't do this to a new battery, but these pretty much stopped working cuz 'they' consider them dead and not to be used anymore anyway. so me doing ?able things to them to make them still work for any amount of time more is only a + in my book, so ya, everything is good now and I'm 95% happy with it. only downside i have is no more charge meter. but that's ok, i can tell by how it feels enough.
You cleaned the contacts very carefully. Wouldn't that alone help it to recharge properly?
I'm no pro contractor and rely on channels like yours for help in a lot areas.. But I do know more than most about lithium ion and have built batteries 10x the size and power of these power tool packs.. And letting you know "reviving" batteries is a bad idea. In this scenario, one of the cells has lost more voltage than allowed by the bms. This type of thing happens all the time because not all cells age the same way. When that happens the low cell can react unpredictabily and begin to discharge by itself when the others in the pack are fine. That low cell can get even lower and with a little bad luck can go into thermal runaway and catch fire even if you just leave it on a shelf undisturbed.. If you hack a pack and revive it... You're only abusing one or more bad cells more and increasing the odds of things from going from bad to much worse.
Same hacks as most YT videos, never work in our batteries, cell voltage were too low for it BMS to recognize the transfer
I have my charger setting in a metal cookie sheet, just incase 😢
I've been watching you channel for some time now but really recommending folks to "jump " their batteries? NO WAY! One little spark and now you could have a handful of flaming lithium battery with knife blades sticking out and no way to extinguish it? There's a reason the charger is not allowing the battery to charge! Possibly a bad (shorted) cell or unbalanced cells, possibly there was some moister intrusion and a damaged circuit board. Cell balance can be checked with a Milwaukee scan tool (not available to the public). Also there are a couple versions of Milwaukee chargers similar to the one you are using, some of the older chargers will not charge the newer batteries. And if you want to play "mad scientist" with the batteries at the very least wear safety glasses and gloves, and never ever leave the batteries and charger unattended and never on a flammable surface! By the way if in fact there is a shorted cell in one and you "plug" a good battery into the shorted battery it you can burn the fusible link up in the good battery! Is it really worth the chance?
You're saying that when you using a grinder throwing a shower of sparks I could blow up my battery. NOT! Your premise is that a spark caused by jumping the batteries in their factory enclosed covers would somehow ignite the cells inside that cover or some sort of mystery gas that doesn't occur on Lithium Cells.
The only real danger might be if you shunt them backwards (short) or use an outside power source of much higher voltage.
If you're uncomfortable don't do it. If you are, great way to save lots of money. In today's economy, every but counts.
Fine! Don't do it! Go bash another page!
Yes, it’s worth it. And make sure you put your PFD on before leaving home today like a good boy…just in case of floods or deluge.
One thing that I have experienced with my Milwaukee batteries from time to time I can put them on the charger and they will charge normally. Then again sometimes I can put one of them on the charger but for a second or two it’ll stay red like it’s charging and I go to walk away and it’ll start flashing red and green, like what does that mean?
Bad cell.
Great Hack!!!
This is what we use to do with the old clamp shell phones
I wonder if you can do that with Ryobi batteries?
Absolutely
Awesome!!!
Damn! I threw one of these away recently.
Three bars isn't 75% charged. Read the fine print
The doggy style mounting method. Simple 😂
Missionary is not recommended and it will cause sparks, like an angry dissatisfied wife.
Will you need to do this method with that same battery each time it drains? Why don't the chargers have a feature that revives them? Is this a scam to sell more batteries? Hmmm.
I guess in a pinch, but there's no current limiter for that.
I have watched so many ways to revive a battery and not one has ever worked at all and I got about 8 of them when it dies its dead , Period .
true that
This method also works to rechage rocky relationships...
🤣🤣🤣
anyone else suspect that this is a deliberate design flaw?
What to do when 1 cell goes flat & the circuit puts it to sleep?
yeah buddy. you will learn through the years all of this stuff is thrown away when it comes right down to it. next thing you know the tool brand you invested all your hard earned money into will change the battery design and your old stuff will become obsolete. after all the goal of every corporation is to make as much money as they possibly can. your experience may vary. as long as you can keep making an income with use of your power tools I think thats what really matters. so you can afford the new stuff when the old stuff becomes obsolete.
This "trick" is how you get around all that silly safety stuff (BMS) and turn your old, dying power tool battery into a bona fide fire hazard.
You think just cleaning the terminals is what fixed it, not the stupid pairing?
Good stuff
You can definitely get shocked. I wouldn't leave those blades just hanging out like that
Really. With a low voltage DC power source? You clearly don't know how this works. You can get burnt if you are touching the razor blades and they touch each other. But that is a burn, completely different than a shock.
While you are cleaning contacts, why not clean all of them? The ones in the middle have an important function too, or they wouldn't be there.
This is a perfect example of someone to NEVER listen to...
now show us how to revive m12 batteries!
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I have stream light battery something and a Computer battery
You look like Fred Flintstone
WILLLLLLMA!
I remember other comments on this guy’s channel from you ‘Chicago Cu-t’. I got you pegged as an a-hole! The question is: Why do you keep watching dude’s excellent channel if all you can do is be negative? Go douche somewhere else.
They just fail again though as they discharge, it's not a permanent fix by no means, it's more a fudge than a fix
smart
This procedure is extremely dangerous!
It may (and mostly will) work well but you're playing with fire. You can easily burn down your shed, garage or house.
I've seen close calls because of battery failures (including a laptop at my own house).
This is nothing like jumpstarting a car!
For lithium batteries connecting a full battery to an empty battery introduces a risk of fire or explosion because lithium batteries have a low internal resistance and can provide hundreds of amperes.
If there's a significant imbalance you can easily overvolt a cell and cause a thermal event because you bypass the BMS (it does not control power but only communicates to the charger to tell it to shut off).
I have revived dead or bad performing batteries but I open the case and connect a balance charger to the cells.
This way there's no chance of overvolting a single cell and it properly balances the whole pack.
This procedure still isn't considered safe by any means because you're tampering with a lithium battery but it's very useful to resurrect a bad performing battery.
There might be an even better solution:
Try to warranty the battery because you still might have warranty on your battery even if you think you don't.
This is an old NiMh battery trick. If you're doing this with lithium cells you are risking a fire.
you need to change the title of the video and take out the word ANY....this method did not work on my ridgid octane battery that was doing the same thing...its dead and will not recharge after trying this
It will work on any brand, but not ALL batteries. But it’s worth trying before buying a new one!
The battery has a bad/failing cell. It'll never be near full power again.
What is this joke. Why would you cut the scene of putting the battery back on the charger when you literally had the battery right next to it
I tried all this. None of it works.
Your battery is ready for the land fill broski.
Sorry, this won't revive a truly "dead" battery. What's actually happening is that the discharged battery isn't putting out enough voltage for the "smart" charger to think a battery has been plugged in. When the "dead" battery is connected to a "good" battery for a short period of time like this, and then put on the charger, it has the required voltage to put the charger in charge mode. If this doesn't work, then your battery is truly dead--recycle it, and buy a replacement.
Worked for me. I’ve been using that battery for several weeks now
This don’t work for makita
Well’ool
That just shows how crap those makes are, Makita would show a fault on the charger.
makita does not have this problem!
Haha nice one
There are numerous videos on YT with this info. It will only work with a good Li-Ion battery pack that has become discharged below the acceptable voltage determined by the battery management circuit board. Since around 2016 it seems the quality of these batteries has fallen off a cliff. An 18650 battery in good condition will read about 4.2 vdc. Being they are wired 2 in parallel and then in series, any issue will most likely involve 1 or more sets of batteries. I have had to replace as many as 6 out of 10 in one battery pack. They must be replaced with preferrably the same brand and amperage rating. Some of the batteries will fail "open" with No continuity and will never function properly until they have been replaced. Walk On ! ☺♥†♪♫ 11-16-24
Your contacts are very dirty. Blow them with an air compressor and then swap them with Q-Tips and Isopropyl alcohol.
Stick to HVAC. Please.
This crap is why I do not own a single battery powered tool. My Grandpa's old drill is still working great, after several replacements of brushes and bearings. He bought it new during WW2 while he was building bombers for Boeing. My uncle uses it almost every day for something or another because he just loves the feel of that hefty metal drill in his hand and knows it won't stop until he reaches the end of his extension cord. These battery powered tools give up too easily. The batteries go all metric and that's just an added expense as long as you can till buy the same battery. Then after 10 r 15 years that battery gets obsoleted and the drill is useless. I would rather have a tool that will last 80 years and keep on going. Yeah I will be long dead by then but my grandkids will think I was a friggin hero for leaving behind a legacy of tools that don't end up in landfills. That's not to say that the average corded tool will last, but some will. Look for lots of steel and aluminum, not a lot of zymak and plastic. Look for "Made in USA" and not made in China. Costs more, worth more.
2 minute vid, my man.
Just buy Makita and batteries 🔋 last forever . So far mine 8 yrs and still kicking . Ryobi the worse 2-4yrs
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