18650 batteries not charging

[camilozk]

Hi!

I bought some 18650 batteries in ebay (http://www.ebay.com/itm/4x-6000mAh-...569397?hash=item3d00366335:g:ndwAAOSwgQ9VxTXR). They are probably not good quality, but it is so difficult to know when you are buying good batteries and when you are buying crap...

The thing is that I havent used them so much, just a couple of times, and now I was using one until total exhaustion. When trying to charge it again, it doesnt charge it. The charger displays immediately its green light, which is supposed to mean that the battery is now full.

Is there something to do to force the charge?

How does the charger operates? When does it charge and when does it stop charging?

If the battery is faulty, what does this exactly mean?

thanks in advance for your patience and ideas

 

[cjdelphi]

I've read stories of 18650 cells simply being removed from dead laptops repackaged and sold on ebay!

Lithiums are easily destroyed by completely discharging it... to "revive" it enough to charge you need to supply it a few hundred ma of current at 4.2v until the voltage is high enough for the smart charger to continue charging it...

Resistor/current limiting

 

[camilozk]

got it.

I used this kind of charger to pull the voltage up (http://www.ebay.com/itm/12136766635...49&var=420310765089&ssPageName=STRK:MEBIDX:IT) and apparently now it is charging correctly, measuring 3.6 already.

if the battery was fully discharged, this means that it has no protection right? If protected, the circuit would have prevented the discharged if I understood correctly, right?

 

[cjdelphi]

Either no protection or the cells are really bad, a true 2600mah battery costs around $20