I bought 4 Panasonic 3400mah 18650 cells from a chinese based dealer and when I put them in the charger (Nitecore intellicharger I4 about 3 years old) they all charged up no problem, I used them in my Fenix TK75 for about a week (probably about 15 minutes every night) then took them out to recharge, 3 charged up to 3 lights on the charger no problem but one will not charge any more then one light on the Nitecore no mater which position it is in in the charger. Is this just a dud cell or could there be another problem?
18650 wont charge
- Thread starter tonym1
- Start date
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That seems a little disconcerting.
Do you have a multimeter or voltmeter to check the voltage?
I assume you've changed the charging slot on the 1 bar battery to make sure it's not the charger?
Do you have a multimeter or voltmeter to check the voltage?
I assume you've changed the charging slot on the 1 bar battery to make sure it's not the charger?
its the same in any slot, will have to check the voltage.
samgab
Flashlight Enthusiast
They're probably protected, and most likely you need to reset the protection circuit on that one. A little zap of 3-4V from one of the good batteries should do it. Some chargers have a built in protection circuit reset feature, but maybe your I4 doesn't have that.
If this is the case, and they are protected cells, there won't be any harm to the cell, it will have just gone into protected mode which disconnects the cell from the end terminal electronically to prevent overdischarge.
If they aren't protected cells, then it's another story.
If this is the case, and they are protected cells, there won't be any harm to the cell, it will have just gone into protected mode which disconnects the cell from the end terminal electronically to prevent overdischarge.
If they aren't protected cells, then it's another story.
samgab
Flashlight Enthusiast
Okay, so as I mentioned above, your cell will be fine, it just needs a small quick voltage zap to reset it, and it will be okay.
In future, try not to discharge your cells low enough to trigger the protection circuit, as it's really only there as a last resort safety feature.
In future, try not to discharge your cells low enough to trigger the protection circuit, as it's really only there as a last resort safety feature.
samgab
Flashlight Enthusiast
Excuse me, as I only have the TK70, not the TK75, but doesn't the manual have some info about a low voltage warning, and a battery level indicator mode for the TK75? Something like; when off, double-click the master switch to enter power state display mode, and the number and brightness of the LEDs will let you know the battery state?
https://www.fenixtactical.com/manuals/fenix-tk75-3-user-manual.pdf
samgab
Flashlight Enthusiast
Those voltage readings sound weird. If zapping it and then charging it doesn't work, there's a possibility that it may be a dud cell, or dud protection circuit on that cell... Let us know what happens.
bella-headlight
Newly Enlightened
If the protection circuit had been tripped the cell would have read 0v & not "The cell was 3.3v before it went in the charger and 3.5v when taken out "
ChrisGarrett
Flashlight Enthusiast
Yep.
Rule out the charger by using another known 'good' charger.
Try charging up other cells/batteries and see what you see.
Always try and rule things out ONE VARIABLE AT A TIME.
Chris
