battery testing

[Narcisith]

Okay so here's a super noob question. I have a protected 18650 cell with the wire leads (Canadian Panasonic 3400mah) and I don't know if it's still good. After finishing my install I have no power and I think my charger is defective but I don't know for sure. How can I check to see if the battery is good? Can you just simply connect the leads to a multimeter? Is that any different than just connecting the battery leads to each other and essentially activating the PCB protection?

[Jenny]

Connecting the leads to a multimeter is the right way to do that. Shorting the battery is the wrong way to do it, particularly with a Li-ion battery. You run the risk of exothermic reaction.

[Silver Serpent]

Note: "exothermic reaction" is the scientific way to say it will catch on fire and/or explode. Definitely don't touch the + and - terminals together on a li-ion.

[Narcisith]

Thanks guys!

Bear in mind I had no intention of touching the battery leads together...I just wanted to make sure connecting them to the multimeter leads was not going to have the same effect. Thanks again!

[Warlock]

A meter will tell you if s battery has voltage output but technically you need a battery tester in order to put a load on the battery. Thou for smaller batteries you should be ok just checking g for voltage.

[Narcisith]

So after trying to get a voltage reading yesterday I came up zeros. Would that be indicative of the PCB being tripped or would the battery still produce voltage? I'm going to replace both my charger and recharge port as I'm pretty certain at least 1 of them was a dud. I just thought of this but could I take my LED (+) and (-) leads and connect them to the battery as another test? Would an 18650 Li-ion battery tester work both on cells with and without leads? Sorry for all of the questions, I've never worked with these kinds of batteries before and there are just some crazy horror stories out there!

[Jay-gon Jinn]

If there is no voltage from the cell, the PCB may be tripped. Usually putting it in the charger for a few seconds will reset that and you should get a reading from the battery somewhere between 3.4-4.2 volts.