zag Posted October 17, 2017 Posted October 17, 2017 (edited) Hi all, I am currently building a Lithium Ion DIY Powerwall at home to compliment my solar panels. Looking for old laptop battery packs to break up. The basic idea is to scavenge Laptop battery packs, break them open, test the individual cells then build them back into a larger pack like this: So if anyone has any old battery packs they want to get rid of instead of recycling them please let me know. I have a special charger that will refresh low capacity or even dead packs. I can pickup around the London or Thames valley area, or can pay for full postage and maybe even something on top if good packs. Edited October 17, 2017 by zag 1
synaesthesia Posted October 17, 2017 Posted October 17, 2017 Have been working towards this myself to power my mancave Got about 60 cells so far from old laptop batteries; for those interested, typically a laptop battery will contain 4 to 6 cells and it's usually only one of them that fails. And better still, more often than not that one can be revived with a decent enough charger like the Bmax kit.
bald_pig Posted October 17, 2017 Posted October 17, 2017 Have been working towards this myself to power my mancave Got about 60 cells so far from old laptop batteries; for those interested, typically a laptop battery will contain 4 to 6 cells and it's usually only one of them that fails. And better still, more often than not that one can be revived with a decent enough charger like the Bmax kit. Damn, why didn't I think of posting here?!? I've been salvaging cells from dead batteries here, but I'm not making a powerwall yet, I'm making a portable power pack for camping, eventually it will be solar rechargeable in the field (literally!) I've also found that it's just one pair dead in each pack I've opened, apart from one particular revision of HP battery where the supporting circuitry has failed!
synaesthesia Posted October 17, 2017 Posted October 17, 2017 My project started off exactly the same, I have a 9 cell setup (3 x 3 cells in series) which I use for night fishing, and is enough to run the lights, charge 2 phones fully, portable radio and still last multiple trips.
zag Posted October 17, 2017 Author Posted October 17, 2017 I'm currently testing and reviving using the Opus BT-C3100 http://lygte-info.dk/pic/Opus/BT-C3100/DSC_4721.jpg Works quite well, i've been getting on average above 2000 mAh on most batteries Can't believe I have been giving so many packs away to our recyclers for the last 10 years!! arghh
synaesthesia Posted October 17, 2017 Posted October 17, 2017 Aye, I've been rocking one of these: https://www.rcmoment.com/p-rm2407.html?currency=GBP&Warehouse=DE&aid=rmsplagb1&gclid=Cj0KCQjw1JbPBRCrARIsAOKj2PmEFFEZLx8JjFP9bqVkHg105KWlIvg34po51LOgMANPHxrgH9IaWRcaAsgnEALw_wcB great for all lithium ion stuff although will do just about anything. Working so often with 18650 batteries these days it's been a godsend. Plus it makes you popular with vapers if they need a battery quick!
bald_pig Posted October 17, 2017 Posted October 17, 2017 I'm currently testing and reviving using the Opus BT-C3100 http://lygte-info.dk/pic/Opus/BT-C3100/DSC_4721.jpg Works quite well, i've been getting on average above 2000 mAh on most batteries Can't believe I have been giving so many packs away to our recyclers for the last 10 years!! arghh I went a little cheaper: https://www.aliexpress.com/item/5PCS-TP4056-1A-Lipo-Battery-Charging-Board-Charger-Module-lithium-battery-DIY-MICRO-Port-Mike-USB/32711377227.html?spm=2114.search0104.3.18.62xgRU&ws_ab_test=searchweb0_0,searchweb201602_5_10152_10065_10151_10130_10068_10344_10345_10342_10343_10340_10341_10190_10307_10303_10060_10155_10154_10056_10055_10054_10539_10538_10537_10059_10536_10535_10534_10533_100031_10099_10338_10103_10102_5590020_10052_10053_10107_10050_10142_10051_10324_10325_10084_10083_5370020_10080_10082_10081_5610020_10110_10111_10112_10113_10114_10179_10312_10313_10314_10184_10078_10079_10073,searchweb201603_2,ppcSwitch_5&btsid=688320fd-72ae-4fe8-9080-e2e0d32dae94&algo_expid=46e87ac3-64d3-4b0d-803d-443b39acc166-2&algo_pvid=46e87ac3-64d3-4b0d-803d-443b39acc166
mikeprice Posted October 17, 2017 Posted October 17, 2017 Hmmm I didn't think that was possible or safe for that matter I have an Ebike which uses a HUGE battery thingy that I believe is stuffed with cells - it would be imteresting to take it apart and see what is inside but I have been too scared of shorting one of the cells is there a web sit ethat has info about it?? thanks Mike
zag Posted October 17, 2017 Author Posted October 17, 2017 (edited) E-Bikes will have a bunch of 18650 cells in just soldered together in series. Same cells as a normal laptop but maybe a higher capacity. E-Bike info: https://endless-sphere.com/forums/ DIY Powerwall info: D.I.Y. Powerwalls - Building Tesla inspired 18650 Powerwalls. Both also have large facebook groups. Edited October 17, 2017 by zag
synaesthesia Posted October 17, 2017 Posted October 17, 2017 It's as safe as you make it, but when separating cells you must be sure to be careful when cutting contacts. The outside of the case just under the plastic protection is negative.
bald_pig Posted October 17, 2017 Posted October 17, 2017 It's as safe as you make it, but when separating cells you must be sure to be careful when cutting contacts. The outside of the case just under the plastic protection is negative. You'd be surprised, I accidentally shorted one, had a bright arc and a warm battery, but no thermal runaway or anything like that, you need a fully charged battery or prolonged shorting to have any real problems, wouldn't recommend it though!
synaesthesia Posted October 17, 2017 Posted October 17, 2017 It's surprising how much energy those things can both store and let out Have shorted them a few times when soldering thankfully with no ill effects - either to battery or me!
mikeprice Posted October 17, 2017 Posted October 17, 2017 It's surprising how much energy those things can both store and let out Have shorted them a few times when soldering thankfully with no ill effects - either to battery or me! That's why I am bit wary of then OH shorted out an ecig battery once by using the wrong charger - with interesting effects
rad Posted October 17, 2017 Posted October 17, 2017 @zag Are UPS batteries any good? I’m in your area so can meet if yes. Unsure if I have any laptop batteries left, got rid of some in the summer.
zag Posted October 18, 2017 Author Posted October 18, 2017 Nah UPS batteries will be Lead Acid and are no good really. Li-ion can store a magnitude more power in less space which is why they are so nice for all these kind of projects. I have a 160ah lead acid battery in my camper van hooked up to a solar panel, and its an absolute beast!! 45KG
DavR Posted February 8, 2018 Posted February 8, 2018 @zag, are you still after these? About to replace 20 Dell laptop batteries - let me know! North London pickup.
bald_pig Posted February 8, 2018 Posted February 8, 2018 If not, I'll take 2nd dibs on these, so long as I can tube and train to you! On another note, I got my new charger today, I picked up a Lii-500 charger, can be used at home or from a cig lighter socket, you can charge Ni-Mh as well as Li-ion, and you can chuck some Li-ions in and use as a power bank if you need to!
DavR Posted February 8, 2018 Posted February 8, 2018 Righto! Between the two of you it will be good to see these go to a good home
mikeprice Posted February 8, 2018 Posted February 8, 2018 How safe is it to dismantle these things - I have an old e-bike battery which would cost over £300 to replace - could be interesting to try to refurbish it
bald_pig Posted February 8, 2018 Posted February 8, 2018 Anything from this: to this: to this! https://www.youtube.com/watch?v=gz3hCqjk4yc
crc-ict Posted February 9, 2018 Posted February 9, 2018 (edited) How safe is it to dismantle these things - I have an old e-bike battery which would cost over £300 to replace - could be interesting to try to refurbish it The dismantling is reasonably safe as long as you are careful. The danger with the 18650 cells these things are made up from is that the whole outer case of the cell is the negative pole. This means that on the top, you only have a narrow gap between positive and negative, so it is very easy to short out between the case (negative) and the positive contact on the top. The bigger danger with repurposing laptop battery cells is the type of cells used - generally laptop batteries are built using 'ICR' chemistry Li-Ion cells, which have a high energy density and are cheap, but at the expense of relatively low current capability and inherent instability of their chemistry when abused, or charged/discharged at high currents. These ICR cells are the ones that get Li-Ion the 'bad name' and reputation for being dangerous. For that reason, I doubt laptop cells would be suitable for an e-bike battery as they would not be safe with the levels of discharge current required. The general laptop cells can only be safely discharged at 1C, so a 2500mAh cell can only safely discharge 2.5A for example, whereas a more dedicated high-drain cell like an IMR can sustain currents of 20-30A depending on spec. More info on types etc here: https://batterybro.com/blogs/18650-wholesale-battery-reviews/18880255-battery-chemistry-finally-explained Edited February 9, 2018 by crc-ict 1
DavR Posted May 3, 2018 Posted May 3, 2018 UPDATE - if anyone is still looking, I still have 20 old battery packs going spare. North London pickup, available until half term hols, when they'll go out with my electrical waste!
bald_pig Posted May 4, 2018 Posted May 4, 2018 UPDATE - if anyone is still looking, I still have 20 old battery packs going spare. North London pickup, available until half term hols, when they'll go out with my electrical waste! Apologies, turns out it's a bugger to get from my work in SE London to yours! I was going to see when I would be off work to head over, should've kept you in the loop.
DavR Posted May 4, 2018 Posted May 4, 2018 Apologies, turns out it's a bugger to get from my work in SE London to yours! I was going to see when I would be off work to head over, should've kept you in the loop. The North-South divide is a powerful thing! I'll PM you...
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