Reviving Lithium Ion Batteries in a PEV (Personal Electric Vehicle) 

Some notes: I'm sorry, but this video does not contain spectacular explosions or fires resulting from mistreatment of lithium-ion batteries. That kind of content is reserved for an upcoming piece on a controlled test of a piece of safety equipment. This video is meant as a discussion around a general safety practice regarding the ownership and use of lithium-ion batteries, specifically those made of the commonly available chemistries that are most commonly used in current day light personal electric vehicles. Onewheels, electric skateboards, electric unicycles, ebikes, scooters, etc. While this may not be the most visually exciting video, the topic has come up often in both my shop, and on some online platforms. Thank you for your viewership, and my apologies in advance for any oversights in the information I discuss.

Great video Mario! I don't know how I missed this in my feed. Looking forward to the suppression bag video. Keep the content rolling.

Super informative video Mario! Thanks for your content !!!

I learned so much from this, thanks Mario!

Enjoying your vids...thank you for the education.

Love you Mr Garage ❤

Learned a lot! Thank you!

Wonderful video, thank you!

Man, thanks for explaining the physical issues arising from the chemistry breaking down. I have a 2nd hand XR I was trying to recover after previous owner had water damage in the battery box. I did a very low rate, lowered voltage direct-charge to see if I could kick it back to life (after seeing some people get success with cells which had only recently been over-discharged)- it didn’t take much charge, so I’m definitely writing off the battery now as I’ve no idea how long it’s been that low - not sure if the BMS is still alive either, but it’s (at least not directly) going to try to set me on fire.

Great explanation

the cells can be recovered even with dendrite state, it takes special attention and 1 cell at a time - so it is timely and costly to do. Typically you take the cell and over-volt it for a second to break up the dendrites. The issue is - they are still inside, just not connected. So they are more likely to form again. For low-use applications, this is fine. Recover the cells from battery packs, and use them in a flash light or what not, then when the battery "flats" again - its time to recycle it. Good practice to not re-package a cell that has been over-discharged into another pack of any size, as it's not a question of "if" it will fail, but "when" it will fail again. I would not recommend any more than 2 'was once flat' Li-ion batteries in the same circuit, for similar danger concerns. I recovered a bunch of 'flat' cells and individually charged them until they held an actual charge. Over the years, 2 of the 7 (that I have in use still today) have re-flatted, but they got lots of recharges into their lifespan again. Those 2, got marked with "F" for "flat" once, and "FX" for "Flat, Dead" - FX cells for my system, are time to recycle. No matter 'if' i could recover it or not and get it to hold a charge, it has gone well past it's normal expected time (since once flatted in a pack) so I feel much better about recycling them. What do I use the currently 5 of the 'once flatted' cells in? Small load applications like flashlights and fans. Things that aren't above typically 2 cells of Voltage, nor with high amp drawn use. I refuse to use more than 2 "F" cells together, due to the fact I know they both had flatted before, and this just seems like it would be prone to re-flat faster. Overall... generally speaking - if i didn't have to pay to have my cells recycled. (yes... it's a stupid sytem.) I wouldn't take this effort to get 'extra life' out of them. But as I do have to pay per pound to recycle my batteries, I try to get as much 'safe use' out of them as possible. From battery packs, to individual cells, finally to the recycle bin, that extra little step seems to help a ton in the long run.

Just tossed out 28 recovered Samsung cells from an Ego battery after watching this. They were all at 0.11-0.23v when I disassembled the pack and all took ~90% of their capacity, but the lose voltage pretty quickly. Charger brings them up to 4.2v and they self-discharge to 4.11-4.13v within about 30m. Was hoping to use them for a low-amperage draw application, but no... not worth the risk. I'm out $25, but better than my house, OW, motorcycles, etc... catching on fire.

Solid video dude, glad to hear someone talking about this and having proper discussion around cell/battery safety. It's often a lot of just "someone say no, someone says yes" without the knowledge of WHY.

You should NEVER bulk charge lithium ion cells without a BMS, as shown in the video. This is because the cells will become unbalanced, leading to risk of some cells being overcharged. Having said that, "reviving" cells like this, almost never works (the cell usually works poorly afterwards), but even if one is going to do this, it needs to be done per parallel bank eg balance charging and obviously at very low current. The internal impedance needs to be tested during charge-discharge afterwards to see if it is still in spec - this is how you know if there is significant dendrite formation or not. If you have no idea how to test the impedance during the charge-discharge cycle, then you need to hand the pack over to a battery recycler.

I have heard that usually the issue with doing this is because when a battery gets discharged this far, almost always one of the cells has been reverse charged which almost instantly kills it. The first cell to reach 0 capacity, and with how fast the voltage drops at such a low level, even just 50mah of difference, can make it so that the first dead cell drops and gets charged reverse to -2v. Suffice to say, that's bad. That's what takes the copper right off the plate. The only safe way to recover a battery is to.. not, you can only recover the cells and find out which ones got damaged and to what extent. The best way to tell is to charge and then discharge them and see which ones quickly drop from 2.5-3v to 2, etc. It only takes milliwatts of drain to pull that down.

Hey Mario, have you ever measured temperarure of a lithium battery fire?

Can you make a video that talks about the component costs vs prices of replacement batteries on the market? If i remember correctly, you mentioned that the pint battery you made cost about $100 in parts but the chi battery sells fro 325. is there $225 in labor involved in producing a battery?

Can you use the dead 9v battery for a low powered LED lighting and still draw low current and recharge back to 9v again?

I’ve had my board sitting since December at 1 1/2 bars of energy left of 4 bars of energy. Is it safe to recharge it now?

Good stuff. The battery could be disassembled and each cell tested individually. If my understanding is correct, sometimes just a couple of cells will fail while others in the pack are fine. You can charge the cells individually to a predetermined state and observe their power loss over time to find the bad batteries. Obviously that’s added danger, tools, and know-how

Hey Mario, I think I need some help. My friend build me CBXR battery, but when I plug all in it seems that board is always on and power button flashing 4 times. I know what that flashing means, but it don’t know why my board is always on.

Years ago i tried recovering a small helicopter battery that was about the size of a cracker. I knew it was suspect so i stayed in the room while i made the attempt. A couple of minutes later i heard a "pssss." I looked, it was about the size of an apple. Next, BOOM! Scared the sht out of me. Blew up, and fell to the carpet floor. It took about 5 ceareal size bowls of water to get it to stop smoldering. Due to the location i dont think it would have burned the house down but it would have melted a lot more carpet. A cracker sized 2s battery!! Scared me for life. I simple don't deal with suspect batteries anymore.

Hi Mario I am an original GT40 owner. My gt40 battery has sat for a year. Is it just junk now?

hi i just have a question should i try to revive a dead lithium ion battery lol jk awesome video and very interesting, i use these things all the time but barely know anything about the science behind it so this video was very informative and useful

Hello, I see this video has been done about a year ago. It sounds like I have my answer though. I have a scooter lithium ion battery with 18650s inside. The battery is a 67.2 volt,16S-12P that reads 0.441 with my DVOM at either of the 2 yellow XT60 plugs. Not the smaller guage wires on the tamiya style or look alike plug. The voltage is 0.441 I rode the scooter a few months ago and it was fine. I hooked it up to the Scooters' factory charger and forgot about it. I disconnected the charger. Turned power on. It lit up. Showed 66.7 volts then immediately fell and to 20.1 and cut off. Would not turn back on. Replacement battery is ridiculous at $1300. But sounds like the recommendation is to don't bother with it. Just recycle it and replace it. Yes?

I have a 21 Ah 36 V battery and it has 20 V and it is died. What can I do?

Is there a way to tell if your battery has been recovered before? My XRs were bought used and anyone wanting an XR now will have to buy it used and will not know the conditions the previous owner left it in. Great informational video by the way.

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Can you fix mine i left for 1 month or maybe a little bit more time and know charger dont want charge bms stoped i dint want try charging the battety my self so if tou can i pay you thank you

Hey, I don't mind staring at a power supply charging a dead battery. There hasn't been a video of yours that isn't quality content.

Where Are you located

I wouldn't do it like this. I'd open the case of the battery and charge the low cell only. If a cell is bad in there you will make the voltage go above 4.2 on a cell and also cause electroplating destroying the good cells

I sending to you its 72v 40ah battery

Risky, yet you charge it on a wooden board in your workshop