Building Lithium-Ion Battery Packs from Re-cycled E-waste

Lately I have been scrapping laptop batteries and using the cells to build 4S8P battery packs (approx 14.1VDC.) I used a 3D-Printer to create the battery holder which was very time consuming as it is a slower model. You can get the files needed to print the parts at https://www.thingiverse.com/thing:1320696 Every cell is tested for performance before being made use of.

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The battery pack is not yet complete, The wire fuses and jumpers between sections are not soldered on to the bus bars. I will use 22AWG copper wire for te fuses which should melt at about 6A.

This is one of the parts before I trimmed away the "brim" which is all the extra plastic used to help support the object while you print.

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Preparing the cells for the jumper wire (designed to burn at 6A) and then soldering on all the jumpers to create (2) tiers of 7.4V (2S each) has been tedious. Do NOT attempt this without having some decent quality soldering flux. I use a flux pen (Kester 951) any decent brand will be fine. You need to use a flat broad top with a decent soldering iron that can reach about 800F (426C), good quality solder (rosin core) for electtronics. I used 22AWG solid copper wire as the fuse wire.

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After a lot of tedious soldering I was completed!

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Updated 2019-06-14

So this is not really "e-waste" and I am using all new batteries but I decided to build some more battery packs that can be used for almost any application each providing roughly 25AH and will be easily interchangeable and easily charged.

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This is the assembly and testing line. I am able to test and charge (4) 18650 batteries every 20-hours so it is slow. When I have filled a complete module I will begin to bolt them together using the threaded rods, installing the buss bars and measuring voltages, When I have assembled (2) complete 2S8P modules I will bolt them together and then place a jumper between the 2 complete modules to form an 4S8P battery pack.

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I use a piece of sandpaper to scrub the terminal ends of each pole on every battery, then apply some solder paste. I use a large Weller gun to pre-solder both poles and then I solder the pair batteries together. Since this is designed to be part of a 4S battery pack the batteries themselves are wired in series. The module it is 2S8P (the buss bars for positive and negative are in parallel within the module itself. )

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There is an assembly order which involves batteries waiting to be tested and charged, batteries that have been solders and the complete 2S module waiting to be bolted together with the spacer snd, buss bars installed and other various things.

Summary: I have been using the prototype recycled battery pack as in put to a (solar) charge controller I use that has a built-in 10A 12V power supply and it is perfect for the job, I feed the output of the 10A power supply to a power distribution unit called the "Rig Runner" and it uses andersen power pole connectors with fused outputs.

If you have seen other parts of this wiki you will have seen I always devise ways to produce or use improvised power. Whether it is in a Field Day environment (Yay!) or a genuine power emergency I create things to let me continue to function at a reasonable level in the face of almost any situation.

I will continue to write more about these battery packs, I am excited to create "packs" of immediate and portable power using this great design!