How to tell if L-ion batt is protected

Hello,
I have several 18560 batts from laptop packs. I am not sure how to tell
if they are protected or not? Is there a way to tell without trying to run
one down and then trying to put the DMM on it ....potentially ruining the
cell? I attached a pic...after removing the green plastic liner so I could
read the codes printed on it:
SF US18650GR
T G5145MCO2W

I'll move your thread to the Batteries section...

Please be extremely careful with that cell with the insulation gone - you shouldn't have taken it off and it needs to be properly replaced, although if the cell reads below 2.5V it probably won't be worth persevering with it.

It is an unprotected cell, btw.

Thats a sony 18650, Not protected.

The protection PCB would have fallen off when you removed the shrink wrap.
You can not use the cell without the green shrink wrap. 2+ cells will short to the battery tube , and I am not exactly sure what will happen if this occurs. 1 cell will remain constant-ON, since the metal will be touching the battery tube.

I would just toss it in the recycle bin... it should look like this:



there needs to be a black washer/insulator around the +B, this along with the shrink wrap isolate the -B from +B and prevent accidental shorting.

Batteries from packs does not have the protection pcb, because thatis a pcb in the pack that is common for all the cells used in the pack.
The batteries probably has the PTC protection.

You can see some more about protection here: The anatomy of a protected battery

as has already been typed:
with just the bare cell, there is no protection driver attached, so no protection at all.

Get some shrink wrap and put it over the cells, so they can be used, but are not protected.

or, get some protection drivers and try to put them onto the cell and put the shrink wrap over then
(but, to be honest, I do not dare to try that)

yellow said:

or, get some protection drivers and try to put them onto the cell and put the shrink wrap over then
(but, to be honest, I do not dare to try that)

Click to expand...

I have heard about others doing this... I have never tried though. it hardly seems like its worth the risk.

thanks for the replies folks. i only removed the wrap on the one in the pick to check it out. The others charge/ discharge fine and work well in both of my lights. Its not worth the cost/time to add a circuit board as I would rather just purchase some protected cells if i dedide to go that route.

Thanks again for all the help