normally I have a fairly decent hit rate with my salvages, perhaps 40-50%, but the last one I did was terrible. Found 5 packs in one go, 4 with 18650 and another with those funky rectangular li-ions. One whole pack was junk (0V) and 3 had a single duff pair, which is pretty common. Even found some nice looking Sanyos.
Anyway, the 1st two pairs discharged and charged up fine, with ~4.5Ah per pair. The next two pairs had perhaps 1Ah per pair, so they got tossed (recycled). Then the single sanyos started heating up (never had that before) inside my safety bag, which was a bit scary, so they got tossed. Then one of the flat li-ions heated up and got tossed, but the other 2 seemed ok.
Overall, out of 26 I got 4 useful 18650s and 2 possibly useful flat li-ions. Such is the luck of the draw, but I think the excitement of finding 5 in one go made the disappointment worse!
Sorry to hear about that. I had a friend that used to say, “Some days you gets chickens, some days you gets feathers.” For some reason remembering that usually makes me feel better about days like you just had.
thanks. The 2 packs I pulled apart before that were great, 4 cells each at either 2600mAh or 2300mAh, so I can’t complain (well, I can, but I shouldn’t).
The square ones are weird and rarely seen flat li-ions, usually found in camcorder and camera battery packs. These came from what must have been a slim laptop before li-pos gained widespread adoption outside of Apple. I’ll probably use them for little battery powered closet lights.
yeah, that’s true. Shouldn’t grumble, but every once in a while it’s nice to do so I did cut my finger twice on the tabs, does that count?
"Of the 240 batteries (18 Samsung ICR18650-26F; 36 LG BD318650; & 186 Sony US18650GR 8A), I decided to keep only 4. That's 1.7% of the pool. Only 18 batteries had capacities over 1000mAh. The 4 I kept have capacities just shy of 2000mAh."
last month I pulled 18 batteries from 3 HP packs. 12 LG cells and 6 sanyo cells.
All 12 LG cells have 800mAH only
All 6 Sanyo cells have 400 - 600mAH
personally I had only one time sucess in HP pack 18650 pull. That pack had two dead samsung batteries. rest of 4 give me 1800mAH
I pulled 9 MOLI batteries from 10 year old pack (german brand) and they all give me 1000mAH (1500mAH rated)
Also pulled 12 Sony 18650 batteries from two sony packs and 6 of them (same pack) give me 1500mAH (2200mAH rated)
other pack’s 6 also give me 1500mAH but they have too high self discharge issue.
holy cow Bigwood, that sure puts things into perspective Sorry to hear about all that wasted effort. A good 2/3 to 3/4 of the packs I tear down have one (or at most 2) duff parallel pairs and usually the other pairs are fine. I also now test the cells as parallel pairs, which cuts down on the initial testing time.
What a bugger though, that must have been so disappointing.
@Pavithra - I had a bunch of low capacity cells when I started doing salvages, but I’ve been luckier over the last year or so with most of the decent ones having >2Ah. I even found a bunch of 3Ah+ li-pos from Macbook Pro batteries (the positive to working at a university, academics love Macbooks), which went into a power tool pack. I’ve gotten a lot better at turfing the low capacity ones now - if the cell voltage jumps to >4V from empty with a 1/2C charge rate, I don’t even bother charging it.
Thanks for the thread guys. With all the tips & tricks shared I may revisit laptop diving this winter again when it's too cold and miserable to go outside.
I did cut my finger twice on the tabs, does that count?
Sorry to hear about all that wasted effort. A good 2/3 to 3/4 of the packs I tear down have one (or at most 2) duff parallel pairs and usually the other pairs are fine. I also now test the cells as parallel pairs, which cuts down on the initial testing time.