I have a pair of Ultrafire ICR123A 800mAH 3V rechargeable lithium batteries that have only seen 4 cycles and have loss their capacity to hold a charge. I have stowed them for about a year with a charge of around 2.8-3V but when I took them out recently I noticed that they rapidly discharge within a minute or two at low to medium loads of 350-500mA. I tried charging them and notice that their voltage climbs back to 3.6V in less than an hour but lose the charge as rapidly. I know that these are cheap but the frugal side of me wants to try to save them somehow.
I have read of a technique of applying 5V pulse to rejuvenate lithium batteries in https://budgetlightforum.com/t/-/5590 but need more details. How long should the 5V pulse be, etc? I have a lab grade 5A 0-35V adjustable power supply that I can use to deliver the pulse but need more info and advice.
Since you are able to charge it, it's not the protection circuit's fault, so the 5V-pulse trick won't work.
I'm afraid your cells are bad and need to be discarded of. They might even be dangerous to use.
Are these really 3V ICR? ICR usually stands for Lithium-Cobalt chemistry, which means 3.7V nominal voltage. In that case, 2.8-3V is clearly to low and probably has damaged your cell.
Thank you for the info Dr Jones. These are 3V ICRs, the green Ultrafires. Specs indicate 3.6V fully charged and 2.0V minimum. I use a separate 3.6V charger for them, was able to use them for 4 cycles and they worked fine. Maybe they ought to be cycle used to maintain them. Maybe I'm better off with primary CR123s as I hardly use these.