Back from the DEAD! Lithium Batteries!

*** USE CAUTION!!! ***

Lithium Batteries can & will catch on fire or explode if overheated! Do not attempt to revive completely drained, damaged, or unknown batteries --- only attempt to revive them IF they are still holding a significant charge! (as shown in the video)

MOST "dead" batteries are beyond repair --- meaning you never want to disassemble them or replace parts. If this trick does not work, return the dead pack to the manufacturer or recycling center!! DO NOT OPEN THE PACK UP!

Do NOT attempt this indoors!

Do NOT attempt this near flammable items!

ONLY attempt this outside in a driveway or parking lot in case of fire!

If you are not comfortable, do not attempt ---- contact the manufacturer for a replacement and/or bring the battery to your local recycling center for disposal.

[jameshalleron]

Thankyou for explaining how to charge a dead battery without alot of unnecessary chatter. Your warnings are warranted and much appreciated.

[ocdtechtalk]

Excellent video I've watched several being an electrical engineer you're the only person who covered gauge of wire. The only other thing I would recommend is to put in a inline fuse. Thanks for sharing.

[patcotsman]

This is a spot on video. I have done a similar thing by using a variable power supply and adjusting it's output to limit current to less than one amp. You didn't need background music or gloves----congrats!

[cactassdupree]

I like the jumpers you built. And the explanation is spot on.

[robsdeviceunknown]

So I bought a lot of about 11 batteries, and some other misc milwaukee tools. for like $350. I think the seller was trying to pull a fast one on me. All batteries were so low that one light wouldn't light up. After watching this I charged them ALL. Jokes on him now. 1x M12 with that 1H saw, 2 M18 Circular saws, 11x2AH Batteries, 1x60V DeWalt and 1x6AH DeWalt oh and a DeWalt abrasive cutoff saw(needed 9 dollar brushes, why on a new saw I dunno) all of it was brand new. All works now. Boy I owe you guys one for sure.

[jhm]

Appreciate the video! I did this with a porter cable battery that only registered 4 volts and wouldn’t charge. Now I’m able to use the impact driver the battery was connected to. Thanks!

[juanr]

Thanks for sharing your expertise. I would like to highlight your “beyond excellent” verbal skills.

[kennethdalebristow]

Thank you for being so thorough on your procedure and safety.

[deanlevett]

Excellent advice had a nearly new battery, that wouldn't charge from the charger. Tried your jump start. Gave it 5mins, and now it is charging from the charger. Thank you for your video, saved me £50. 👍👍👍

[freedomseeker]

Great content. Also great delivery. You've got the right voice for it, tempo is good, diction is great. Thanks for doing this.

[TheZigwah]

Wow you are truly an Exceptional Educator
Great explanation of and clear warnings
Thorough without excess
Ive done this technique before, I just was so happy to see a YouTuber give the complete correct information

[mySelf-yxhw]

Did the same thing myself
bought an 18 volt Hitachi drill with 2 dead batteries
got the batteries going again using the same method and it's still going strong more than 2 years later

good advice about doing this outdoors, friend of mine was swapping old Nicad batteries and fitting Lion
we did warn him about the charging issues, he later sold it on and had to pay the money back when the batteries caught fire and almost burned down the guys kitchen

[alnavajo]

Love it! I did the same setup to charge my 10 year old stream light battery and it brought it back to life. I started off with 0.159 millivolts when I last checked it it was at 2.9 volts. I had to my new battery to trick the charger into sensing the battery voltage from my new battery to charge my old battery once it started sensing 2 volts I started charging my old battery directly with the charger.

[exgenica]

KEEP DRY SAND NEARBY FOR LITHIUM BATTERY FIRE CONTROL
Do NOT use water to try to put out any lithium battery fire that occurs. That includes some fire extinguishers. Water can in fact make lithium-based fires much worse and/or cause explosive projection of flammable material to nearby objects/people/pets.
Keep a fairly large amount of sand or dirt on hand to smother any lithium battery that starts to smoke or is on fire, or that you hear start to "crackle", or if you see it start to discolor/blacken.

Also, I would keep a separate appropriate fire extinguishing method on hand to help control/put out any secondary fire(s) that are not adjacent to the battery itself (e.g. if fire spreads to grass, trash, clothing, or other objects). Because lithium battery fires can be VERY fast, explosive, and quickly spread and "jump" over small areas of cleared ground into nearby brush, furniture, etc...I'd personally keep handy an extinguisher rated at a MINIMUM of "10A".

I'd also make sure I wasn't testing things near sources of flammable liquids, other electrical equipment, and people or animals and over-hanging tree and bush leaves and branches.

I realize this is boring stuff, but sometimes we just forget to think of these things when in "debug" mode.

[nkuutujeremiahbrianchoosen]

Thank I will try out and see if it helps

[jackkohanim]

Great info. I have two DeWALT 40v batteries. One of them stopped charging last year and I didn't want to spend the $192 to replace it. For some reason I held on to it thinking I would be able to take it apart and replace the guts of it. Well, now with this video, I followed your instructions and wired it up initially for 5 seconds and it pushed it up from 36.9 to 38.1 and now it's charging.
Thanks for the detailed explanation of what happened and why it wasn't working.
Hope all is good with you.

[jJimmyBGreat]

I'm glad you could get back to drilling random holes in scrap 2x4 in a machine vise. Thanks for the info. I'm gonna go try this.

[mark]

Mark Munro. The DC motor is also a DC generator turn your drill with another drill with the switch held down. That puppy should take a charge.

[timsemerdjian]

Awsome mate, I'll follow your suggestion and see how it goes .
A very comprehensive explanation, well done .

[mrstanskaggs]

The cells on this unit are Samsung INR18650 cells (5 of them). They are 3.6V cells which comes out at 18 volts. The packs are labeled as 20 volts in that 20 volts is the charging voltage for these cells (4.2V charging X5=20V). If the cells get imbalanced in terms of standing voltage, it reports as a bad battery. The multiple connectors on the battery pack reach in between the cells.


Looking at the connectors on the battery, you should see roughly 20V from right side (+) related to each of the other three connectors... but no reading from the left connector to either of the middle connectors in any combination.


Opening the battery shell, you can specifically measure across any individual battery. Each battery unloaded should show 4.1 volts charged. The key is not to look for 4.1 volts though, but a difference between each cell individually. The circuit board has a comparator circuit which makes sure each cell is within 0.1V difference (charger is a balancing charger in other words).


These cells are the same as people put in those nasty vape machines, so you should not be too scared of them.. I find it best to charge each cell alone and watching the resulting voltage on each cell until they level out to the point that the comparator allows them to charge on the charger once again.


... sounds a little complicated, but it is simple actually.. The packs are not glued together thankfully, and the sides of the batteries are easy to access once the case is opened...