0 Volts Batteries

Hi. Im new in the project.

I founded a lot of battery at 0 volts or less than 1.5 volts.
These batteries can be restored.

i yes, please provide methods and/or instructions.

Guillermo

Batteries at 0.9V or higher I usually just throw in the Opus and monitor them carefully. Anything less than that goes in the recycle bin.

Here's an image from the Facebook group of someone who tried to "bump charge" recover low voltage cells.

I dont bother with 0v cells, recycle them.

1v and over I would apply 3v at 50mA using a bench power supply and them move them over to a regular charger after the voltage rises. Monitor temperature closely.

Trying to recover 0V cells is a bit tricky. The first question is to find out why it's 0V. If its the CID that popped, tossed it (this is tested by doing an IR reading; if it's infinite, it's disconnected). The second question is is it really 0V, or about .01V. That can be a difference in being able to recover it or not. If there is some voltage in it, it must be charged very carefully. <50mA charge would be recommended until it reaches 2V or more. Then you can ramp up the current to about 150mA and charge normally. But, keep a watchful eye on it in case it gets hot or starts to bulge like mike showed above.
If the voltage truly is 0V, do not bump charge it. Toss it. It's not worth the risk. Btw, if you don't know, bump charge is taking another cell that 2V or more and parallel connecting it to the 0V cell. The 2V cell will dump voltage in to the other cell in the attempt to equal the voltage between them. This can be very dangerous.

I have recovered cells in the past that have had 0V for about 5 years and returned to 1100mAh, ok low but they were around new 2500mAh to start with as they were in very old laptop battery packs from 1999.... Connect 4V at 1A for 2-4 seconds and then quickly put them into a charger at a very LOW charge rate. The reason for the quick 4V is to give a surface charge internally so the terminals do not register 0V in the charger, more current will just gas the cell and damage it.

As per Korishan the charger needs to be slow.

CrimpDaddy said:

I dont bother with 0v cells, recycle them.

1v and over I would apply 3v at 50mA using a bench power supply and them move them over to a regular charger after the voltage rises. Monitor temperature closely.

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I have had plenty of failures recovering 0v cells. Most have issues with self discharge, or their capacity is too degraded.

However when I have time I charge them up. Notmany come out healthy. But I have certainly have had some excellent results from some. Most recently some LG batteries came out at 2600mah, with no self discharge after a month.

If you have time it is worth the effort. It really does depend on how the battery got to 0v and how long it stayed there.

It is critical that 0v batteries get recharged very slowly. 100ma, max.I charge them in large quantities inparallel at 50ma per cell or less until they reach 2.8v or so. Sometimes you will have to hunt down the odd self discharging cell so it does not drag down the others.

Once they reach 2.8v I charge them at approx 250ma per cell, until they reach approximately storage charge - 2.7v. I leave them sit for a week. If they do not self discharge, I continue to test as normal. About half of the cells I get at 0v show signs of self discharge within a few hours.

So far I have about 20 cells that have fully recovered from 0v with capacities above 2000mah. I have lots that are below 1000mah. And countless that I have discarded.

Many people do not bother with 0v batteries, as it does take time revive them, and I will say the results are probably not worth the effort. But it sure is satisfying when you do recover a good battery.

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Korishan said:

If the voltage truly is 0V, do not bump charge it. Toss it. It's not worth the risk. Btw, if you don't know, bump charge is taking another cell that 2V or more and parallel connecting it to the 0V cell. The 2V cell will dump voltage in to the other cell in the attempt to equal the voltage between them. This can be very dangerous.

Click to expand...

I use a very discharged NiMh battery connected in series to get my charger to deliver a charge to 0v batteries. The trick is start very slowly at 10ma per cell the voltage will rise to 1v very quickly.

I have tried bump starting batteries. This is dangerous, and does not work.

Cells over 1v are easy. Just connect to an RC charger an use the NiMh program. I usually set the safety timer to 30 mins and charge at 50ma per cell. That way there is no possibility of overcharging the batteries if I get distracted.

I need to stay caught up on the forum posts, I missed the pic of my pregnant cells ;-) Recovering 0 volt cells is a waste of time but every once in a while I find a good cell that was just dragged down by a failing mate, so it is sort of addictive like cracking open a laptop battery and finding it full of good Panasonic greys. Ive charged hundreds of bumped cells (and processed thousands now) but always in 200-300mA trickle chargers and never run into issues (other than them mostly being garbage). Only when I got lazy and threw some fresh bumped straight into an Opus did I get an overheater that blew up the shrink with hot electrolyte. I also dont pre-charge cells in TP-4056s, I think that unless a cell is 3+ volts it puts too much load on the cell too fast, lower voltage cells need trickle charging as the first step.