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TESTING 18650 BATTERIES

gsc1ugs

New Member
I have a lot of 18650 batteries out of makita batteries i need testing because the makita charger doesnt like them, need to test if the cells are dead because most will charge up individually using a cheaper device and read around 4 volts each but when together the makita charger said its bad. I do know if one goes down the whole 18v battery wont work
 

audioguru

Well-Known Member
Most Helpful Member
An older Li-Ion or Li-PO is dangerous to charge if it has been discharged to less than 3V. Most Chinese protection circuits disconnect the load too low at 2.5V.
A charger should attempt charging with a very low current and if the voltage does not slowly rise then the battery is disconnected, and an error flag is set.
 

Nigel Goodwin

Super Moderator
Most Helpful Member
I am salvaging 18650 batteries too. My charger will not charge a 18650 if voltage is less than 3v. Anything 3v and up I can charge. Batteries less than 3v I put in parallel with a 4v battery to charge it above 3v. Once battery is above 3v the charger will charge it. I charge 40 batteries then return a month later to test them. Batteries 4v I keep. Batteries less than 3v I trash. If batteries is a bit low like 3.7v I charge it 1 more time to see what happens after 1 month. If battery is low again I trash it.
Buy an XTAR VC8, as well as charging batteries it will test them for you as well (grad mode).
 

gary350

Well-Known Member
This is my battery charger. It charges at 1000ma and tests the battery as it charges. If there is a problem charger stops charging. It charges batteries up to 4.2v.
100_6458 - Copy.JPG
 

Nigel Goodwin

Super Moderator
Most Helpful Member
This is my battery charger. It charges at 1000ma and tests the battery as it charges. If there is a problem charger stops charging. It charges batteries up to 4.2v.

If it's so great why are asking questions? - and from your post it isn't so great, it's not 'testing' the batteries - only charging them. The only 'testing' is to make sure they are suitable for charging - not if they are any good.

The one I mentioned does full capacity testing, as well as just charging.
 

gary350

Well-Known Member
If it's so great why are asking questions? - and from your post it isn't so great, it's not 'testing' the batteries - only charging them. The only 'testing' is to make sure they are suitable for charging - not if they are any good.

The one I mentioned does full capacity testing, as well as just charging.

I am not asking questions, this is not my thread. I only said, this is my battery charger it works for me.
 

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