So after reading about all the free and near free lithium ion batteries other members were finding in various battery packs I decided I just had to take part in the fun. True to form I dove in head first and rather obsessively searched for likely sources. Home Depot and Lowes were top on my list but I learned picking can be near impossible if the nice door greeter is on duty. These folks can be real defenders of company policy. The folks at radio shack are great and incredibly accommodating, it's too bad they don't get many batteries in.
The mother lode of laptop packs came from a nice fellow making a living by buying dead laptops out of his garage. I don't suspect he makes a mint but he's got tons of battery packs. Networking with friends turned up a couple packs but the best of the best comes from touring the local transfer stations. The local townies run these facilities and can be very stingy when it comes to anything the town can make a dime on. Fortunately they know battery packs are not one of those money makers. Several of the transfer stations actually set up a box or a shelf corner to collect packs for me. Only one, up in the hills of Greenwood Maine, gave me the cold shoulder. The kindly three-toothed gentleman quoted me the town rules like scripture and no counter points were to be considered.
All told in the last six weeks I have gathered about three dozen laptop packs, twelve to eighteen tool packs and a handful of other miscellaneous battery packs. I have sorted about 250 -300 cells, mostly 18650s with a few 26700s, 18490s, and cr123 primaries mixed in. The few pleasant surprises included a couple packs containing barely used panasonic cr123s and a six pack of tenergy platinum 5000 mah sub-c nimh cells.
I charged the sub Cs and tried three of them in a BLF 17dd/triple xm-l t6 and drew and easy 12 amps. The most obvious thing to do next was to try four of them. The triple poof was so fast I never even got a dmm reading. Good cells, bad brain.
Of the 18650s only 60 or so seem like healthy cells. Some are obvious champs while others teeter on the edge of the recycle bin. I don't keep cells under 3 volts or those that get hot on the charger. Those that self discharge past 4.1 volt get tossed as do those that can't get to 5 amps on a DD triple xp-g2. I have kept a sample of lower performing cells for further examination. The opus 2.1 charger I ordered should tell the rest of the story.
I don't know why i wrote this wall of text other than it seems like some folks that might be interested in cell harvesting may be having trouble getting started. What I've learned is to just go and ask, except at home improvement box stores. And wear gloves. Just keep in mind there doesn't seem to be any sort of obvious stopping point in this quest. 18650s used to be kind of rare and precious, now they're strewn about all over the place and I chuck them on a whim. It's a good obsession.
I wouldn't put it past the overzealous biddies at home depot do do a little investigative dusting. I found moli IMR 26700s in old 3ah Milwaukee and Rigid tool packs. I got a total of 10 safe cells out of 15 but their performance was not up to their legend. Eight amps to a DD triple XM-L with a fast fall to a steady 6 amps does not impress me. Course my other 26mm cells are powerizers so I may expect too much. The Opus will tell the tale.
Deadgoat,
That's what she said.
202bimike,
I'm pretty sure the panasonic cr123 primaries came out of medical devices. The 18490s came out of a camera battery and I got three 2600mah pink samsungs out of a pack to who knows what. I just grab any pack that says lithium ion or that could hold an 18650. I use an xtar wpII and a Nitecore Intellicharger I4, both appear to be good chargers though at 375ma per cell the nitecore is a bit slow.
Otanacious,
Almost every transfer station allowed me to paw through their current pile when I asked. If you try it, be aware that they don't pull the batteries out of the laptops they receive so that's another question to ask. I have not tried an e-waste facility as yet, not sure there are any in Maine. I suppose success would depend on what organization was running the facility.
Just an update, went to a local transfer station and asked to check out the computer bins. Found a pile of laptops ready to be shipped to ...where ever they go. Tore out the batteries.
20 lithium ion packs and 7 old NIMH packs plus a NIMH duracel pack. Got some ripping to do.
I’ve used my few laptop pulls to power some USB power banks. I may even mod a few crappy ones with non-replaceable batteries that have wandered my way. Some of the crappy ones have good electronics coupled with a a “3000 mAh” battery that’s closer to 750. I’ve got some salvaged Sonys that test 2000 on my Opus, which would make those power banks suddenly useful. The wife stopped using one because it sucked, and I pulled it apart and I think I can swap out the UF or whatever cell is in there.
Very good info in that OP kyfishguy. Thank you for reporting. Lots of ideas I never thought to try in there. That haul in Post 6 is crazy. Hope you find some good stuff in there.
I opened the best looking packs first and got about 45 cells over 3 volts and rated for 2400 to 2600mah. About half were panasonics. The NIMH packs contained sanyo 4500mah 18650 cells, I believe you had a brush with them in the distant past. They're all at zero volts and my intellicharger won't take them. Maybe the opus when I get it.
I’m into modding on free time and I love doing it. I tried battery pack pulling once but did not get good cells. After reading this, I’m seriously contemplating on adding this to my list of hobbies. :bigsmile:
Nice job I’m also an addict I have scouted about every laptop repair place in my city but my mother load came from a guy that works from home doing lap top repairs. He have me 5 boxes of packs!!! About 30packs per box. The only danger is that when you pull so many cells you get clumsy and try to rush it and end up shorting something lol. Maybe it’s because I’m so excited to see what cells are in them! Happy hunting.
I gutted out some laptop packs last week. 3 packs were working and and 2 packs wouldn’t charge. How low can the charge on a cell be to be considered junk? Is 2.5 volts too low?
Working Pull. Sanyo UR18650Y L43C Red, Green tip. Toshiba PA3534U-1BRS 10.8v 4000mAh. 6 cells Test 3.53v
Working Pull. Samsung ICR18650-26C PINK, White tip. Dell Type WW116 11.1v capacity 56wh. 6 cells Test 3.99v
Working Pull. Samsung ICR18650-22F Light Green, White tip. HP 485041-002 10.8v 47wh. 6 cells Test 2.53v
Non Working Pull (Wouldn’t Charge). Samsung ICR18650-20B Light Blue, White tip. High Capacity Power Products aftermarket for Sony Vaio, 14.8v 4000mah 8 cells. 2 cells Test 0.00v DEAD! 6 cells Test 3.77v
As for how low to go before pitching a cell. My personal limit is ~2V for pack pulls. Other people pitch cells that have dropped below manufacturer discharge cut-off specs, typically ~2.8v. I think that is overly cautious for cells coming out of laptop packs.
A properly functioning laptop pack will prevent overdischarge under load, so if cells coming out of a pack have a voltage lower than 3.0v, it is probably because of slow self-discharge. The charge management in laptops/laptop packs typically allows recharging of cells below the cutoff voltage, but limit the current to a few hundred mA until cell voltage gets back to 3v. The Opus charger behaves similarly, as do, I believe, the TP4056/7 IC used in a lot of cheap power banks and charging boards. The IC used in the latest Miller ML-102 also is supposed to implement pre-charging, but I haven’t tested it.
Battery University suggests pitching cells that have been at or below 1.5V for more than a week.
