I have two of four Tenergy 18650 3.7v Li-Ion batteries that won't begin to recharge using my OPUS BT-C3100. In fact the charger doesn't even recognize the batteries are in the charging slots.
Are these batteries dead beyond being brought back?
This charger has a discharge function. But it looks like they are already discharged beyond recognition.
Thoughts?
Try a different charger. If the batteries still won't behave properly when on the other charger, replace those batteries and dispose of them properly, as well as immediately! I don't take any chances with those types of rechargeable batteries. Not worth it. Made a thread awhile back regarding a beloved Klarus light that burned out its own LED but somehow kept putting out light. Just with an ugly black donut hole in the center. Also noticed that the light heated up on Turbo mode
far faster than normal. Immediately turned off the light. Yanked that battery out of there! Got it far away from me. Properly disposed of it later.
I'm not looking for any sort of
vent with flame incident. Those types of rechargeable batteries are supposed to behave a certain way when they are on a charger. A certain way when being used in a flashlight. A certain way when sitting idle in a flashlight.
Any sort of deviation in expected behavior should be dealt with, immediately! Quickly check and analyze the situation, determine the problem, implement the proper solution.
Can't determine the problem? Get rid of them! Done! Not worth trying to recondition them or do anything else with them but properly dispose of them. They're not dangerous.... But they are potentially dangerous when they start acting up. When they behave in any sort of way that is out of normal behavior for them. Yes, I know just how expensive these types of cells are. I definitely know. But if they vent with flame or explode, and you accidentally breath in the toxic fumes they give off.... It's going to cost you a helluva lot more than just the cost of replacing those two cells. I'm sure others will disagree with me. But I watch my cells like a hawk for even the tiniest bit of abnormal behavior. And, take a zero tolerance approach to such cells when they do behave differently than they are supposed to.