I have made a detailed video on this. There's a lot more information on this new video: kzfaq.info/get/bejne/r9t8l8xl1LqbqH0.html

The lesson of the clip for me is: the use of the little magnets!

This is the simplest method that most videos describe, but I prefer a safer method. This way can make the battery heat up and explode. I use a bench power supply where I can dial in the voltage and the current. I limit the current to about 50 milliamps, and then I gradually raise the voltage to the point where it starts to take current. Sometimes this can be as high as 30 volts. Once it starts to charge, I reduce the voltage to about 4V, and I turn up the current to about 100 mA, and let it charge for a few minutes. At this point I transfer it to a proper charger, because it monitors temperature and controls the current, shutting off when the charging is complete. It's particularly useful for older cameras which have dead batteries which no longer take a charge, and the new battery is either very expensive or hard to find.

Great video, something else you can do to revive the cells is to set your RC charger to NiMh mode which does not have Low Voltage protection and set it at 0.1 amps, this will trickle charge the battery to get it above 3.0V and then you can switch it to LiPo mode :)

I've seen this method mentioned in other places, but I particularly appreciate the description explaining the _reason._ 👍 Far too many people just "give a man a fish" instead of teaching. 🤦

Using magnets to hold the leads is very clever!

I just did this and it worked great. I folded a strip of aluminum foil until it was about 1/4" and then tore it in half, I stood the 2 batteries beside each other on one of the foil strips, I laid the other across the top terminals and counted to 20, I put the battery in the charger and it worked! Thanks for the tip!!!

the charger will not charge the battery because if the voltage is below 2.8v the battery became unsafe, good that you are teaching people how to overpass the safety feature

Very helpful thank you. I didn't gave any good 18650's so I used 2 AA Alkaline batteries in series and connected them to the dead 18650 in the same way you showed. Worked surprisingly effectively and only took a few seconds to bring the 18650 up to a chargeable voltage.

For Anyone out there, I used this method with a dead AA NiMH rechargeable battery, and it worked as described.

I'm so glad i stumbled on this! Didn't know you it was a voltage drainage issue, I left my batteries plugged in my gimbal once discharging so I messed up 2 batteries. I didn't know it was a voltage drainage issue with these types of batteries. I didn't have the right tools like a volt meter but fortunately 2 18650 batteries where charging so I charged one. The working 18650 connected to the dead battery through simple soldering wire i had laying around..When i saw the spark i thought it probably fried it..I got paranoid so i only did it for like 10 seconds or less. Just like jump starting a car it instead the battery came back to at least 1 volt and the charger no longer displayed an error and begun charging the dead battery! this works wonders! You saved me having to spend 20 something dollars on new batteries and having to wait for shipping and cancel a video shoot! Thank you!

I tried. It worked. I had 3 expensive and near new 18650 batteries. All VERY flat from a big flashlight. All now charged. I tried 2 different chargers. Thank you.

I am terrible when it comes to anything electrical but I bought the cables & alligator clips shown above, followed the directions to the letter and boom! My left-for-dead 18650's are charging in a wall charger ... something they refused to do for 2 weeks! THANK YOU!!!

A lot of the RC chargers have a power supply or 'smart charge' mode that will allow you to put any current you want through the leads. Super useful.

I love your accent / voice it is so soothing to listen to in a tutorial like this

After watching this, I used an old 5v 1amp charger lying around, cut the end, and attached them (one to +/-) on the 18650 battery and plugged it in. After about 15minutes, pulled it off, and...the battery WORKED! Charged as usual! Thanks!

Your videos are gold...literally...watched your drone vid which gave me the guts to try what i had wondered would work...take my old ecig batteries and replace the weak lipo in it....works great using certain brands of batteries and waaay cheaper and safer than expensive over priced lipos.

That's exactly how I did it and with a very similar charger. It doesn't work long if the battery is too dead but depending on what you need the battery for that's not a big deal. For batteries between 1.5-2.5v they can usually come back to almost perfect health. The older and longer the battery was discharging, the less likely they are to come back to normal.

You are on the correct path to solving the problem. A LiPo battery that reads a very low voltage to the point a charger will not accept it for charging is due to developing a high internal resistance because of a chemical reaction that occurred when it was either discharged too low and/or at a rate higher than safe. This can be fixed by applying a voltage higher than the nominal 4.2 Vmax ( and up to about double that) of what a LiPo should be charged to, and by keeping the current as low as possible (~ at 1/10C of what it is rated) so the chemical imbalance is reversed, internal resistance goes back to a normal low level, thus the battery becomes more ..."accepting" to an incoming charge. As an example connect any ...misbehaving LiPo to a wall wart with about 9 - 12 Volts and a current of as low as possible (ie 100 - 300 mA) and monitor the battery voltage level: It will start to rise slowly. The key is to let it rise very SLOWLY , like ~ 0.1 volts per minute. The slower the better, it depends on your patience just keep an eye on the battery temperature, but if you use a low current it will not warm up, guaranteed. Let the battery reach a little over 4.2 volts (not higher than 4.3 V is recommended) and disconnect it from the wall wart while observing your multimeter display. If the battery settles anywhere above 4 V it is still usable (the higher the better) although it is probably no longer as efficient like when being new. If the voltage is slowing dropping most likely it will go all the way back to an unusable level so at least you know the battery has lived its useful life and recycle it properly. Nice video, I hope I was also of some help too!

I had purchased a new battery after realizing the aftermarket deck I put in my VW Wagon was draining it but was time anyways 2 replace. So it killed the new one. My 20+ year old charger had an issue with power cable eventually fraying so I picked up a new digital smart charger (EverStart Maxx 50A,15A,3A trickle). Hooked it up and pressed recalibrate and nothing. I was confused, passed, and gutted. But then I took a step back and thought to myself alright, so I got to work. I replaced the power cable in the old school direct current charger. Tested it and made sure there where no issues. Threw it on the dead battery for a small period of time and once I got it to a quarter to half way of it being charged I tried the digital and it started charging and doing its job. So yes this is a very, very helpful way to get more life out of batteries like these that are believed to be dead. I have a 10 year old 18650 battery from an old original vape pen which broke in my Tactical flashlight and still to this day I use it almost daily taking the dog out. Lasts as long as it did back then and same current too as every 6months I throw the 18650 that came with the flashlight in and double check so I know how it's doing and to re-topoff the stored one to keep it freshly charged while stored.

I cannot believe it works😂 I had an awt 18650 that's been dead for a while, did this whole process in literally 30 seconds and the battery charges! You sir, are a legend.😎😎

Cool trick, man. Just a tip: if you put electricity thought a magnet, with time, this one will be demagnetized. And the magnets also add resistance to the circuit, so it's better if you don't use magnets while charging your batteries. Peace, bro. 👍

Love the magnet idea 😉, that alone is a thumbs up 👍

Using the magnet for contact for charging ...... BRILLIANT....somehow I missed that one all these years......ty sir

Great tips. The magnet trick to conveniently attach leads is also clever. I didn't have a charged lipo battery, but this also works if you have a variable power supply. I just set mine to 3.2V and connected it in parallel to my battery for 30 seconds, and the battery was ready to charge!

Thank you, saved 4 batteries that had been in a flashlight that was left on. My Opus charger would not charge them before I tried this.

you are the boss! i had one 18650 that had only 0.18v charge and its now back at 3.7v and working again thanks alot

Thanks had a brand new item with inbuilt battery, accidentally left on and ran flat over a couple of weeks. Would not light up the LED panel or charge. Pulled the battery out, kick started as explained in this video, put the battery back in and it is now charging as normal. Don't know yet if I have done permanent damage, but looking good so far. Was a life saver because we could not get another 3.7V the same size as the one built into the item.

I have watched this video two times now. I have saved around $120 with your technique! Thank you

Oh my goodness! I followed your instructions and it WORKED like a charm!!! I have a 14650 Li-Ion inside of a plastic case and protector circuit (known as the LIP-8) for an old Sony Mini Disc. I had purchased that battery as an extra backup and failed to actually charge or use it back in the day. The battery was so dead it would not recognize. You got me going my friend - thank you!!!!

Worked for me, thank you so much, some of the comments about corroding insides of the batteries have me worried, I will keep a close eye on them, besides that, my charger wouldn't charge them, now it does! A++

I figured this out myself, too. The electrically conducting magnet trick is the cat's meow. Thank you! Good stuff.

An excellent job. You saved me 4 batteries of 6000 mAh. Thanks a lot.

Thank you so much! I have an 18650 battery that won't charge so was trying to figure out how to zap it without ruining it. Your video is awesome and the tip about using magnets is brilliant! Now I can fix several different things I have that won't charge.

Thanking you for this trick! But, I did my a face palm when you used the magnets on the clips! I love magnets but never thought of that. An age-old problem solved!

Legend, just resuscitated an expensive battery pack. Suspected this battery may have been heavily discharged and left flat. All the cells tested (in small bunches) were ~1.2v (not consistent with cell failure). Carefully adding a little charge by jumping a full 18650 in a holder onto the multimeter probes worked great (maybe building a more permanent rig with a push to close switch may be handy if you do lots of this). De how this battery goes now the charger and controller were happy to charge it.

u just need a high current charger to shock what is inside the battery. And after that u can charge it back to a normal charger. just like ur making a jumper from ur car to a dead battery. thank u sir u refresh my memory. keep going & God bless!

love the magnet trick - never seen that one before! Thanks!

Worked on a 18650!! Only needed 3 seconds and they became really HOT. Be carefull!! Thanks!!!

My friend with the best accent ever ! So happy to stumble upon you again. As always great stuff thanks

Using magnets instead of soldering for a short term connection. -Great idea!!

This is what's called bump charging, i have done this before to my cell's and it does work as long as the cell has not reached it's end life cycle.

Much love! This totally worked for me. Was at 0.15V, placed in parallel for ~10 sec to 1.8V, which was enough for my charger. Good looking out!

I took 2 pieces of twisted tin foil and held it across the ends and counted slowly to 15 and it worked. Thanks!!!

what you can also do is use a Turnigy or imax b6 charger to raise the voltage to get them to charge. all you have to do it swap it to NiMH mode and charge it for a couple seconds until the voltage on the 18560 is 2.25-3v and then you can swap it back to lithium mode and continue charging like normal. it will work for any lithium cells.

For those curious as to why this cell discharged so low and why doing this is risky, here's some quick info: That 18650 cell is a "protected" cell. See the little extra ridge towards the positive side of the battery just before the button top? That's a small circuit board that contains the "protection" circuitry. Something has failed in that circuit, allowing the battery to continue draining past the safe point. By applying voltage directly to the battery like he did here, you're forcing it in through the protection circuit. Sometimes the protection circuit will continue working per normal after this and sometimes it won't. Depends on what happened that cause it to fail, being either a hiccup or something physically damaged. Typically, if the battery pack or device that you're installing this battery into has overheating protection on its own, you'll be ok. But if that device or battery pack doesn't already have that safety measure, you risk the battery blowing up. Be careful when doing this! I've also revived "bad" cells in this manor & those batteries are still working well after years of use. Fortunately, I haven't had one explode yet. Be mindful that if your device gets really warm after doing a revival such as this, that the battery might blow & I would highly advise against using it any further!

This worked well! Thank you! I will say I held the multimeter on the old battery after disconnecting from the new one and the voltage was not holding- but is expected from a battery that was left dead for so long.

There are many ways to "wake up" those cells, the principal being to apply a large enough voltage to them for a brief period of time. That Turnigy charger of yours will do just fine. It looks like it uses the same firmware as the original SkyRC, so just change the battery type to NiMh, max charge current to, say 1 or 2A, and charge it up to about 3V (takes couple of minutes). Then switch over to Li-ion. One advantage is that for weak cells, you can observe that the voltage keeps dropping (i.e., almost impossible to bring them up to 3V). Also it will refuse to charge real dead cells (internally shorted). Three things you should have mentioned playing with these: 1. dead/weak cells can get real hot, so if a cell gets hot during charge, throw it away; 2. perhaps they're really not good -- after charging them up, wait for a few days to see if they can hold the charge. If not, it's time for them to go; 3. don't ever put them in parallel with good cells.

The magnet to hold the leads made the vid..thx..the battery revival was old knowledge

The reason why charging at unlimited current is a bad idea is that when a lithium cell is discharged too low there is nothing formed on the plates, charging at a low current (sub 100mA) will reform the chemistry on the plates if you charge too fast it will cause uneven forming of the plates and WILL cause dendrites which are shorts inside the cell, that do not happen right away and if it is put in a pack it will short out and cause a major chain reaction

Thanks man it works! I had a dead AA very new battery only used it 3 times. Wouldn't charge, when I measure no voltage. I actually used a 9v to give it a jump for only 5 seconds. Then measured 0.8v and now its charging.

At first I was skeptical but deeeeym, this works like a charm! Keep in mind though you need to follow what the guy said to charge it for no more than 30secs cuz in my case the battery got warm 20secs mark and I immediately removed it.

No shit the magnet is both a lightbulb moment and palm to forehead in that order. Thank You for enlightening and keeping me humble friend. Hope you are having a good day.

I came back here to hear you say cells again. If I could thumb it up again I would.

🤟 Worked great for restoring my HS510 drone battery! Was about to tear the battery apart but I just did the jumper wire trick for a few seconds from one of the other HS510 drone batteries and it came back to life and is now charging on the Holy Stone charger. Thx for the great vid!

You should really have some amount of resistance (like a 3V light bulb) in series between the two batteries to limit charge currently (even though it will take longer), as you likely over currenting the battery for a time with possible damage. Even more so if you try to charge a smaller capacity battery from a bigger charged cell, when it could potentially even cause a fire or battery rupture (in the smaller cell). I have an electronics engineering background and having seen lithium battery fires, I recommend treating lithium batteries with great care!

This technique you did with a good discharged only battery. If you try it with a bad quality dead battery, it never ever will bring that back to life. Best regards,

Not usual for me to leave coments. But you rock dude! You have fixed my battery! Thank you so so so much for the good help! You are the best! Thanks heaps!!!!!

I recommend using a resistor in series with the alligator clips to avoid massive current surge into the dead cell :)

I used this technique today to revive a 2.5AH Ryobi 18V ONE+ Battery with great success.

I've enjoyed your accent while watching your various battery videos.

Thanks a lot. Funny cuz the charger and voltage scenario down to the charger indicator lights and color of cell...Got my dead cell up in under 30 seconds!

Cannot believe this worked. No fancy equipment here either. Just a standard battery and tinfoil instead of wire. Thanks!

I tried your method on NI-MH batteries and it worked. Thank you very much for sharing this!

I discharged my battery to far and the charger wouldn't charge it. I tried your suggestion and it worked. Thanks

However the batteries “recovered” in this way will never hold a charge long under load. Over discharging an Li-Ion battery permanently damaging the cell.

Thanks man! Took less than 5 minutes to bring 3 dead Samsung INR back to life.

Uncle Roger shows us how to revive dead cells.

it may show you a good voltage, but i dont think it could work as a regular battery, it wont give you enough current, and will drop voltage so fast.

I think the magnet s on the alligator clips was the coolest and most handy thing I've seen all day. Did you just glue small magnets to them or are they actually magnetic?

Thank you for making a video on how to revive / rejuvenate a battery that is dead or no longer active.

When this works, it works, and it usually will. When it burns, it burns, and it is a very hot and nasty fire. If you add some current limiting and monitoring, you can make the process pretty safe.

I never thought of just using another battery to recharge up a battery enough for a recharging, some great advise, thank you, I needed that. Also the magnets are such a great idea as well, I've already purchased some new small magnets just for doing this technique now. Again thanks a lot, Tom.

Put your turnigy in NiMh-mode and watch you voltage manually, when it reaches about 4v, stop it and charge in LiPo-mode again. In that way, you can force charge into the battery with current limit.

Thanks for this, saved the 18650 battery on my screwdriver!

Thanks for a very clear description of the process as well as the 30 second max charge warning.

@1:53 YOU DIDN'T DISconnect the parallel wires BEFORE testing the lame battery. So you were getting the sum of the whole circuit. Not the actual reading of the lame battery alone. Though this method does work, i would've liked to have seen the actual voltage of the lame battery solo at each test point.

That was really cool!! I thought you would jump the dead battery with a live one with perhaps twice the voltage!! but you did it a lot safer!! and those magnets!!!

Wow magnet as pole connector is brilliant! That can be a way to make a DIY large cell really easily! You can use ferromagnetic material that you just de-magnetize after

I tried this and it works! My mother’s electric wheelchair’s battery was dead because of unused by time. Battery voltage is 24v 20a in normal. But after waiting without charging it descened to 0.0 voltage. There was no energy inside of it. And then i saw this video and i thought to use this trick in a bigger scale. I used to car battery jumper to increase the voltage and i used this methot until the battery increases to 12v. It takes a 10-20 seconds from 0 to 12v. That was the half capasity of it. And then i saw the voltage is discharging so fast as much as jumping to 12v. But it was enough for a moment to charge the battery by normal way with 29.4 v adaptor. Until 15v it was going fast too because the chemistry was deformed but i made it stayed in charge position for 24 hours in max capasity and then finished the battery totally and then i charged for 24 hours again. I did this routine for a few times. Now my battery is healthy as much as it can be. In normal way, wheelchair was taking 30-40 km in full charge with a mix with normal and agressive using and now it s taking 20-25 km in the same using. I dont know how long time it will keep this performans stats but it s better than nothing. For sure it cannot be perfect like the first time but it s a good way if you wanna use the dead batteries. Thank you very much for this trick man. I saved extra good money in my pocket because of you. God bless you.

In most cases its not worth reanimating cells that are discharged far too low (lets say below 1,5 V). You can bring their voltage up, but they won't hold it for very long. Mostly the capacity is gone (90% of it) and they wont work well afterwards. And you take the risk of creating an internal shorts (by dentrits) which can cause severe fires! In some cases you can repair cells that are still above 1,5 V and below 2,5.

It's been my experience that a recharged dead battery cell, by any method I've seen, produces a battery that may have the voltage reading, but the amps are cut dramatically. Which, in turn, makes them run out of charge when used very quickly. The only success I've had is replacing the sulfuric acid in a lead acid battery with magnesium sulfate, which you can buy to take a relaxing hot bath. The car battery lasted for about six months. So, even this is has its limits.

But does it holds charge??

You can do this with your turnigy charger as well, just set it to NiMH and keep an eye on the voltage, since all you're really doing is bringing the voltage back up, the best part is chargers like your turnigy will let you trickle a small amount of charge to give it the best chance of revival without too much heat.

How to keep your multimeter in place-put it in an old cell phone case-brilliant!

Just be careful as the cell can get hot with the rush charge! Charge it up to what it stops charging at and do a discharge test at the cells rated discharge rate for an accurate mAh reading. I typically discharge at .3 A. I rarely have good cells that were very low in voltage or they don't last long.

The US power strip looks like 6 shocked faces in a row.

Oh you have a good power sentry distributor with overvoltage protection! Keep it safe! There are only a few manufacturers are so very good components in it. A good thing!

No matter how you revive them they are good as dead, they won't hold charge for long

Just woke up my 25r's, we will see if they hold charge. Thanks man👍 There was no way I was sticking something under positive to reset cid button 😢

You, good sir, have just saved me the cost of a new battery. Thank you!

Thank you for showing this. I just had a pair of good cells, but unloaded to dead due not use. I made an assumption, that it would work if I put Elektrons in it until the voltage is reached. You proofed me right. Ok ok, few years ago. Doesnt matter. Thank you

that's brilliant. I usually just shock them with 12v from car battery. But this is a lot safer. lol

This method will most likely cause additional degradation to the battery. For really dead cells you should perform a process called "pre-charging" which charges the battery at a very low current. Here's a video by EEvblog that explains it: kzfaq.info/get/bejne/d5ydfsdmxJPFkp8.html

I'd like to observe that while this was successful in reviving my batteries, one of them was charging 2-3x faster than the others, and so it's best to have a 33Ohm resistor handy to place between the contacts so the plastic cover doesn't melt itself by charging too quickly.

You can also switch your computer charger to Nicd charge mode and select 3 cells(3.6v) and maybe like 2amp and let it charge for 30sec or a min(monitor the heat) and it will bring up the voltage enough. Then you can switch over to normal charge mode.

Yes but, once charged how long do those dead cells last compared to a good battery?

Cool trick with the magnets, I will definitely remember that! Would be cool if you can check the capacity of a cell brought back to life like that and maybe try it with an old dead cell as well. BTW, what accent is that? Sounds cool.

I'm sure it's been covered, but on the Turnigy you want to set it to charge NIMH for a short amount of time then as Liion.

Why I never thought of using magnets? Good job!