WWW builds a battery.
My new obsession is with batteries. Li-ion, LiFePO4, all of them. Currently I am recycling 18650 cells. Apparently the whole world currently runs on these. Laptop, Tesla, power tools, e-bikes, you name it, use this cell in some arrangement. The recycling of theses cells is very popular it seems. I bought a few hundred of them for some projects. Average price is about $0.50 / cell. Some of these sell for $5-9.00 each when new! Admittedly I did spend a few bucks on tools but I am building a few out of inexpensive bits from AliExpress. Total investment around $150.00 for tools.
Here I built a small power brick for 5 volt USB use. You see these about for $40-130.00. Case was $3.84 and these batteries were $0.30 ea.
In pictures:
My spreadsheet, I measure capacity and internal resistance to ascertain the the quality and life left in the cell and also use the numbers to group cells with the closest match. That’s important with these as 1 bad cell can take down an entire pack. Not bad in a small pack but some have hundreds of cells!
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This is the case I bought. It’s surprisingly well made for what I paid, really surprising as it is quality stuff! I lucked out on this! The cells were removed from modem battery packs. As some are covered with black stuff or the cover damaged when recovering, I need to put new insulator rings and shrink wrap. You can see that I chose like cells from the SS.
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Close up of the case. Nice and sturdy, the electronics look good, standard stuff there. This is an 8p or 8 cells In parallel for 3.6 volts nominal, 17.8 amp hours. There’s a boost to 5 volts. Damn it’s cool.
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And the completed battery. Nice button under the lightning bolt shows capacity and a double press and it’s a flashlight. Need to wipe it down but it’s all set to go!
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