NicoM Posted August 21, 2018 Share Posted August 21, 2018 Good day everybody. I'm looking for old laptop battery packs in the Cape Town area. I would really appreciate some help as after some phone calls and some googling i was left empty handed. Groete Nico-Merwe Quote Link to comment Share on other sites More sharing options...
Mad Mike Posted September 2, 2018 Share Posted September 2, 2018 On 2018/08/21 at 10:00 PM, NicoM said: Good day everybody. I'm looking for old laptop battery packs in the Cape Town area. I would really appreciate some help as after some phone calls and some googling i was left empty handed. Groete Nico-Merwe @Nicom, I would suggest literally visiting any business that recycles, collects old computers (laptops). Cash in hand has proved a real motivator I have personally found. In my case I was sold the batteries per kilogram will little option on what batteries I took! So far I have collected 1400 old 18650 batteries and have only began sorting through the lot. NicoM and Chris Hobson 2 Quote Link to comment Share on other sites More sharing options...
NicoM Posted September 3, 2018 Author Share Posted September 3, 2018 @Mad Mike, that is what i started doing in the end. I Found about 4 places that are keeping all of there old batteries for me and so far i have about 160 cells that i have not had to pay for at all. Now i just have to wait for the charger so that i can start testing. Quote Link to comment Share on other sites More sharing options...
Mad Mike Posted September 3, 2018 Share Posted September 3, 2018 I wish I could find a place that would give me free batteries but alas I am paying for them. my eventual goal is a 20kVA system so there is a ways to go. I have charging units and capacity testing units ordered from China. The post office has delayed delivery over 6 weeks so I wait. I bought 2 4-cell chargers from Communica in PTA so I am "busy charging 8 batteries a day (at this rate I will be 2 months just charging the batteries...… then when the capacity, resistance testing begins I will be testing 10 batteries a day so another 140days worth of testing and marking the batteries..... Quote Link to comment Share on other sites More sharing options...
NicoM Posted September 6, 2018 Author Share Posted September 6, 2018 I have to ask why will you only be able to do 10 a day ? I have an imax b6 on the way for my charging as i will be charging 8 in parallel ? My discharge testing will be done with the 4 cell opus units so i will be looking at doing around 24 cells a day, fun part about being a student so I'm at home a lot of time and the max discharge time is about 3 hours at the normal 1 amp rate. I also have lots of the lipo pouch cells to play around with, thinking of making a small 4s pack as a mobile power source. Quote Link to comment Share on other sites More sharing options...
seant Posted September 7, 2018 Share Posted September 7, 2018 Be careful of charging 8 in parallel, if you have a bad cell in there you run the risk of things going horribly wrong. Rather do a set up where you can charge cells individually. The Opus is fine for discharge, but you don't have a way to check the internal resistance. A cheap way to seperate cells with a higher internal resistance is time. Charge the cells up do a discharge and then charge then to full 4.2v and leave then for a month. After that if the voltage drops to 4.1v or 4v(You decide an acceptable level) then I'd use them ,below that I'd put them one side. The thing is it is going to take you a long time to sort and process you cells for a 20 Kwh power wall I'd guess about 6 months. Quote Link to comment Share on other sites More sharing options...
NicoM Posted September 7, 2018 Author Share Posted September 7, 2018 I have 20 tp4056 boards on the way i will rather then wait for them to arrive. The bulk of my charging will be done outside in a small brick enclosure that is away from anything that can burn. I have out of curiosity overcharged a fairly large pouch cell just to see what would happen if a cell does go up in smoke. I have to say you get some respect for these cells when you see that thing go off, the whole enclosure was black on the inside and the wire was melted but that was all as soon as the cell had finished burning the smoke stopped as there is nothing there to burn. i have a video but it is about 1.2Gb as i had to wait for the cell to do its thing. As far as i know the Opus BT-C3100 V2.2 can check the internal resistance, i will confirm as soon as it arrives tho I may be wrong. My first pack will be small in the order of 2 or 3 kwh and then the next one will be a big boy. I have had my fair share of accidents (most painful was getting a zap from a camera flash cap ) and have learned when in doubt take it outside. Quote Link to comment Share on other sites More sharing options...
seant Posted September 7, 2018 Share Posted September 7, 2018 Keep at it . Do leave those cell sit for some time and choose the best ones, cause it sucks to have to rebuild a pack once it's in service Quote Link to comment Share on other sites More sharing options...
NicoM Posted September 7, 2018 Author Share Posted September 7, 2018 @seant Thank you very much for the advise. I just have to wait for all the toys to arrive. I will keep this thread updated. Chris Hobson 1 Quote Link to comment Share on other sites More sharing options...
Marco Posted February 14, 2020 Share Posted February 14, 2020 Any progress on this project? Quote Link to comment Share on other sites More sharing options...
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