Electric Bikes - Can Li-Ion packs be home-built?

The less expensive hub motors I have seen use SLA or Ni-metal cells. Is there a supplier for Lithium cells?

Is this something that can (or should not) be done? I'm wanting to build a 36v pack of around 10 Amp hrs. for way less than $1000.

Tom

4 or 5 36V Dewalt tool packs should get you into the ballpark for your 10Ah needs. Probably $500-$700 depending on how many chargers you want. Those packs will need to be modified slightly to bypass BMS for discharge and wired in parallel for powering the bike but it should be a relatively safe way to go if you maintain the stock charging scheme and monitor discharge voltage.

Other angle would require 7 A123 Systems developer kits ($770) and then you would have to do all assembly and design proper charging scheme for same. Unless you have a well stocked workshop, you'll be spending another $300 for chargers, hook-up wire, casings, etc.

I did the developer kit route for 24V 10 AH packs but have decided I would probably go the Dewalt route (same A123 Systems cells) if I needed to do it again and/or for 36V packs.

Milwaukee tools use a 28V lithium pack scheme that other folks have modified more easily than the Dewalt. But, those would require further rework for 36V operation and then the stock chargers would need to be replaced as well.

Check out the Dewalt stuff and learn all you can - I think that's gonna be your best way to snag 36V lithium system for reasonable price. Maybe start with one 36V 2.3Ah pack until you figure out the best way to manage everything for your eventual 10Ah design?