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Old 10-11-2012, 10:28 AM   #3 (permalink)
Ryland
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Most EV's don't use 1,000's, except for Tesla, because they are stuck in their old ways of doing things, they are using spiral wound cells that look kind of like flashlight batteries, hybrid battery packs are currently the same way.
Vehicles like the Nissan Leaf, Chevy Volt, Mitsubishi i, Ford Focus-EV and I think even the Plug-in Prius all use pouch or prismatic cells, lithium cells that are also called Large Format, I have 8 such cells sitting on my desk right now, 100amp hour 3.2v cells the size of a chunk of 2x6 9" long/tall.

The advantage of course with small cells is that you can make your pack in pretty much any shape you want, they are also already mass produced for things like tools and lap tops, the draw back, and it's a big draw back, is that each battery has a connection and that is a point that it can fail, so you have 10,000 flashlight batteries and you end up with 10,000 connections and in theory you should have a battery management system that can connect to all 10,000 batteries so you have 10,000 little wires running to a BMS, then you run in to an issue of how do you tap power off that battery pack and have it stay even? wire, even short runs, has resistance, so the battery closest to the output cable will have the highest draw!
My electric car is a low voltage car, running at 48v, if I end up with these batteries in it instead of my motorcycle... it will have 16 connections between batteries, 16 BMS connections and my lithium batteries are wired up in sets of 4 with solid bars between cells, so my interconnect cables with their crimp on connectors and so on are reduced down to 3 and 2 power cables coming off each side of the pack.
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