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Message: <blockquote data-quote="PV1" data-source="post: 24324" data-attributes="member: 591">I'm torn. For $2,400, I can get a bunch of used laptop cells and build a 12P88S auxiliary pack out of 1,056 cells. This is the easier of the two routes I'm thinking of, as there are already tabs welded to each group of 3 cells with a spot for wire interconnects between parallel groups. However, this may lead to less capacity than I hope for with more weight and space taken. Plus, there are current limits that I have to deal with.http://liionwholesale.com has Panasonic cells that hold 3.4 Ah and can discharge 6.8 amps continuous. For a bulk purchase of 500 cells or more, the cost is $5.17 per cell. So, for a pack with similar (actually more) capacity, it would take 792 of these cells wired 9P88S and cost $4,100. With the current share between the packs, I calculated that the most that the car will pull from the aux. pack is 57 amps, which is below the max. continuous output of 61.2 amps. Of course, with differences in internal resistance, there may be more than 57 amps draw on the aux pack, but I plan to have a separate ammeter on the aux pack and limit throttle based on amperage. The downside to these cells is that I now have to weld/solder tabs to each cell and then connect each cell. I want to use 18650 cells as they can be packaged in a way as to not affect cabin storage or handling (less than 100 lbs. in place of the foam floor in the back).</blockquote>