Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers

LPF Donation via Stripe | LPF Donation - Other Methods

Links below open in new window

ArcticMyst Security by Avery

revive dead lithium battery?

Joined
Dec 31, 2012
Messages
904
Points
0
I found a lost and forgotten lithium battery to my Ryobi cordless drill that looks like the attached photo.

It has zero volts and the smart charger won't charge it and it blinks the error lights.

I've been wondering, if I could just get a little current into to the battery, perhaps the smart charger will take it from there, and I can get some use out of it.

I recognize it will likely have diminished capacity. but hey, if it works for a time to drive a few screws while my others are charging, I am cool with that.

How do we resurrect a completely drained lithium ion battery? is there a trick? Can I use my bench PSU to push some juice into it?
 

Attachments

  • image.jpg
    image.jpg
    22.4 KB · Views: 560





Joined
Sep 25, 2012
Messages
87
Points
0
I have read where people have done this many times. Some people use a NiMh charger to get just enough voltage in them for the Li-ion charger to see them. I would think the PSU would be perfect because you could match the output of the original charger.
You could open the the pack and check voltage on each cell a few times along the way, to be sure no one cell was being over-charged.
 
Joined
Dec 29, 2009
Messages
3,136
Points
63
If the cells read 0V, then that's a sign that there is an internal short in the 0V cell.

More than likely though, the pack has circuitry in it to prevent charging if the cells are overdischarged. If you can crack it open, you will probably find some IMR 18650s in thar, and can measure the individual cells to verify if they are still at a salvageable voltage. Be careful, though, because they are often welded together with strips of metal, and they are easy to short against each-other if you attempt to disassemble it further, i.e. breaking the cells out to individual cells.

protection circuits like what we use on protected single 18650 cells are very simple to reset, you just apply a small charging voltage to unbreak the "breaker." You might consider just applying a charging voltage, or even a few volts under, for a second or two and then reading if the voltage is the cell voltages instead of 0V.
 
Last edited:
Joined
Sep 12, 2007
Messages
9,399
Points
113
Yeah, there's almost certainly going to be one or more totally dead cells in there. You'll need to take it apart and deal with each cell individually. Even if you replace the bad ones, the remaining ones will have reduced capacity and will die soon afterwards because of the unbalanced charging and discharging. It'd be best to either replace all the cells or just buy a new battery.
 




Top