Laptop 18650 battery question

Eh, I’ve done a bunch of pack pulls, maybe 5? 4 Panasonic (IBM Thinkpads) and a Sony pack. Accidentally shorted 2 batteries with shears (sparks flew!), but tossed those out, the rest were all fine.

pretty much what willie said. If you’re careful with charging the cells after each use and not running them all the way down, them being unprotected isn’t a big deal. If you’re really worried about it you can get single cell PCBs from DX for $1-2, although you’d have to check to make sure the over current trip level is high enough.

I’ve done quite a lot of laptop battery packs (including Macbook pros :laughing: and it’s just the luck of the draw what you get. Of the 2 most recent packs (in the recycling bucket, woohoo!), 1 was completely toast with none of the cells holding more than 500mAh and the 2nd was awesome, with just one duff pair (0V) and 2 pairs that yielded between 1800 and 2000mAh. One of them is now in a rear bike light and the other 2 or 3 are about to go into a camping light :slight_smile:

I personally wouldn't use unprotected cells in multiple set ups ..i'ma big fan of unprotected cells and have ripped open about 10 laptop battery packs.Snce i don't have a hobby charger to fully test batteries for me it's sort of seat of the pants ..I recharge and have had good success with cells under 3 volts ...more than I would have thought ..i also have had very good luck with very old battery packs too .the only real tests I use is how much a battery drops after being charged up and left sitting and how well they handle a pretty serious draw against them ...A littl bit subjective but when mixed in to results with very strong new batteries things become very obvious and since they cost next to nothing or ..nothing they are easy to pitch (recycle) ..and when i recycle i often find more cells ..an endless cycle with the best cells floating to the top .

In multiple configurations I run LMR batteries

Ditto this, Willie Nails it pretty much. The only other thing I do is charge-cycle them a few times and let them sit for a 6-7 weeks on a shelf come back and test for LSD characteristics. Any cells that drop to less than 4.15V, I recycle them. This is a difficult test for most used cells to pass. I probably end up throwing out ~70% of the Sony, Samsung and Sanyo cells because they cant hold a charge.

I have found any cell that can meet all these criteria, will have sufficiently low internal resistance and is good for a tough 1-1.5C draw.

My best cell harvests always seem to be Panasonic CGR cells. Whenever I crack open a pack, peer inside and see them… Oooohh!! For whatever reason they hold a charge best, and really deliver on the current draw too.

Yeah, my 2 best pulls are lime and green CGR variants, still had very good capacity after a few years.

Yeah purple CGR18650E cells are the best I have pulled. I also have teal CGR18650D cells that test very well, but are a slightly lower capacity.

ooh, you lucky gits getting Panasonic cells in laptop packs! I usually strike Samsungs and only really the last pack has yielded any with decent capacity (>1500mAh). Most of the cells I’ve harvested I’ve given away as backup cells for bike lights that I’ve made.

What brand’s packs do you find Panasonics in?

I took apart Samsung battery pack recently, and there were Sanyo cells inside, not Samsung… shocked me quite a bit :stuck_out_tongue:

IBM Thinkpads, found the Lime CGR18650CE in a really old laptop, and really good green CGR 18650 AF in a pretty new one.

Sanyos and panasonics have been the best for me ..all the colors of the rainbow on the panisonics .orange purple,lt blue, lime green.

lest success with moli's (sorry canadians)...lg and sonys.. but i've seen very few LG cells

i have no idea what packs they came from...since you can't affect what packs are being recycled i stopped trying to care what cells came from what manufacture ...i think they also change companies as well .The last Dell packs were moli's i think and i expected them to be ....Sony ??

it's like christmas ...you never know what you'll get .:P

+1000! :slight_smile:

unfortunately the recycling centres around here won’t let me strip down batteries to test the cells, so the ones I get either come from request emails to my work listserv or ones dumped in the battery recycling bucket next to the recycling bins outside my lab. Still, it always feels good to give something another lease of life and prevent it ending up in landfill or wherever else li-ion batteries end up!

I found the teal CGR18650D in IBM thinkpad packs, and the purple CGR18650E Lenovo thinkpads. Its very rare though, almost all the cells I have pulled from Lenovo packs are red Sanyos.

Panasonic makes the best 18650 cells by far. I have used mine up to ~4A draw (almost 2C) and they don’t bat an eye to that. Their CGR cells test every bit as good as AW IMR branded cells.

You mean in a trust fire 4000 mah? :stuck_out_tongue:

interesting. I’ve only taken apart one IBM pack and it had something pink or red and not very good in it. I agree wholeheartedly about how good Panasonic cells are though - I bought a bunch of the CGR ones off Rev.Jim and use them in bike light packs, plus I’ve built a couple of NCR18650As into a helmet light pack for a friend.

Ha! I thought they only used those rinky dink li-po packs that you find in bluetooth earpieces :smiley: Those posts were one hell of an eye opener. I’m half tempted to break apart one of my (refunded) eBay 18650s - 500mAh capacity and the internal resistance of a large piece of glass.

500mAh sounds like it’s a wrapped 16340.

I always assume those pics are fake just for fun ..i don't want to know what's in a lithium ion that has no capacity .putting a hacksaw to a battery is low on my list of things to do . a junk cell is just a reason for me to go and recycle and see what's new in the recycling bin ...

I have 8 sanyo lmrs from 2 hitachi drill packs .they came flat as a pancake with very low low low voltage and almost killed my tr001 charger ... it heated up and buzzed and didn't like the amperage these empty cell s were trying to steal from it ..so much so i stopped and gave everyone a short break and let them cool down ...batteries weren't affected or hot the charger was freaked out by them .. once they hit over 3 volts everything chilled out . They are the best batteries I've ever seen.. red sanyo Lmr with hexagon shaped tops /with a blue colored ring around the top

I have been on the lookout for used laptop batteries but can’t seem to find any. I pulled my battery off my Toshiba laptop that I didn’t use anymore and got 6 red 18650s. 2 would only charge to 4.06v and I think were the ones making the pack drain so fast when I did use it. The other four are charge to 4.13+\0.01v. I think they are good and have been using them in my one cell 18650 with no issues. They hold a charge and recharge to same levels.

see this post

Just finished stage 2 of testing cells from 5 packs (3 old Macbook 18650 packs, 2 no name). Total of 32 cells, 6 or 8 got kicked at <3V. The rest charged up fine although 4 of the pink Panasonics I was doubtful about (turns out they were ~300mAh). Then I left them a week and all bar 7 went below 4.1V Recharge testing on individual cells (I did pairs originally to save time) showed that all of the remaining pink Panasonics had lost >10% in a week (boohoo :(), as had half the green Panasonics (both were from Macbook packs). Now I’m left with 3 green Panasonics (~2Ah) and 4 no names (~1.9Ah).

A lot of work and time, but I’m pretty confident in what’s left. It’s interesting to see the different ways in which the packs die - one of the Macbook packs was due to half the cells losing their capacity and the rest self discharging, the other was fine capacity wise but all the cells self discharged and one of the no name packs was the classic “1 pair gone” problem where the other 2 pairs were fine.