I only have a couple hundred cells. I haven't found a cheap source of cells, so I'm making the best use of what I have. My dad has a janitorial supply business. He also still does comercial cleaning at 72 years old. He has a small auto scrubber that has 2 12v SLAbatteries for a 24v pack. The SLA batteries in the machine only last a little over an hour. It pulls about 20 amps. I wanted to build a pack that I could remove the cells to use them somewhere else if I needed to before I get more cells. I got some 3 & 4 cell holders & soldered a buss bar across two 4 cell & one 3 cell holders that I glued together. Then I placed the same # back to back to make a 22p pack with a xt60 connector on the end. I made 7 of these. I made a wire harness with enough length so I can stack them in different configurations. I haven't put the cells in the pack builder yet but it should be about 44 Ah. I have it wired for a smart bms that is on its way from China. I built this pack for less than a set of lead acid replacements.
Well done. I was thinking something along the same lines of using the cell holders to make my packs. Mostly so I could change cells if/when they go bad or get too weak to use effectively in the powerwall.
