i have an emachines e725 laptop that the battery just recently died, keep showing a ” red X” over the battery on the laptop. is it worth stripping for the 18650? are the cells basically dead too? how do i know if a cell is still good? i only know how to read voltage on the dmm. thanks for any helps BLF
battery pack is 10.8v and 4400mah
wouldnt hurt. check voltages of each cell after you strip it, any too low, toss. monitor while charging, if they get hot, toss. let them sit for a while to check for self discharge, if they drain quick, toss.
ok so i just found on my attic an old acer latop that i’ve been there for years, stripped the battery pack, got 6 green cells, checked out voltage on 6 and got 0 reading on all 
, should i try to recharge or just toss?
i would toss them
A voltage of 0 on all makes me wonder….Did you have the Meter on the correct setting? Sorry I ask but just making sure.
Should they truly be 0v….ABSOLUTE TRASH. I wouldnt revive a pack pull that was below 2.8ish volts.
I was thinking the same thing...
ok those 6 cells are gone, just stripped the one on the emachines, got 2.07 reading on all 6, worth keeping?
yes they were all 0, because the second patch, i got 2.06 - 2.08 on all cells. did i do something wrong? i have a cheap cen-tech dmm pickedup at harborfreigh, and set at DCV 20
Any time you drain a Li-ion below ~2.5v your going to do irreversible damage, at 2.0v personally I would toss them but if they’re your only batteries they probably will take a charge, its unlikely they’ll hold their original capacity anymore tho and unless you have a battery tester that’ll show mAh just reading the voltage won’t tell you their health.
I get old laptop/tool battery packs a lot and if the batteries dont come out above 3V I dont even try to charge them, just toss them. To me its absolutely not worth it but you might get some use out of them, if they take a charge they’re better than nothing.
thank you very much, do you happen to know any good affordable mAh reader on the market? also 6 of the batteries i stripped took charge but took nearly 10hrs to fully charge at 4.21 Volt, i measured this morning and the discharged is .01-.02v for about 12hrs, i wonder if that’s ok? i’m using one in e-cigarette and seems like it’s working pretty darn good.
I wouldn’t use unprotected laptop pull cells starting below 2.5V in an e-cigarette for certain! To state the obvious: an explosion/fire on your face is not generally a good idea…
Yes its possible to “revive” some lithium cells but thats just too much risk, especially right on your face…
Didnt you say you bought a few packs of new Acer cells on the other thread? Those should be better cells (test first of course).
yes i ordered panasonic cells from wallbuys, takes forever to get here. and plus i’m just trying to find something. so all the batteries from laptop pack are all unprotected?
I have revived cells from below 2.0 volts and use them in smaller single cell lights with low current demands. That said, I would not use them in high current lights, and I sure as H*** wouldn't use them in anything near my face.
It this is your dmm it can be used as a mAh "reader". It has a DCA section for Amperes and multiple mA ranges. It won't be terribly accurate but it has to be better than nothing. Even meters costing 10 times as much are not very accurate in the lower ranges - mine sure isn't. So unless you're measuring something very important it may be enough for you.
I am curious though. How much current does one of those Ecig devices draw when you take a drag on it? Am I correct in assuming that it only uses power when you are inhaling?
Edit: Yes, cells from a laptop pack are unprotected once you remove them from the pack. The pack itself contains the protection circuitry when used with a laptop.
I would not ever use anything other than good protected cells in an ecig if I used one. Yes, laptop pulls are ALL NOT protected, and the danger is much worse because those cells were drained to below 2.8 or 2.5 (whatever their manufacturer stated safe working range was). So, they are now much higher risk than average 18650s. Wait for the protected Panasonics!
I hear some Ecigs can draw 4.5A or more?
thanks Photon, that is the dmm that i have, but i couldn’t figure out how to test mah, about the ecig i have no idea how much current is drawn per drag ( should of paid attention in chem class in school) but it is power manually everytime u wanna take a hit.
thank you sir, i just threw them away.
Cool, not worth the risk. Maybe this guy can help you with E-cig questions, he says they can pull 5A off a battery (I dont smoke) Thank you "Vaping!"
Just to answer the question a little further, ALL battery pack cells are unprotected, be it tool or laptop or whatever, it’s impossible for them to be protected actually, most packs will have a protection circuit for the whole pack but the individual cells must be unprotected.