Big Electric Car Motor, Small Conversion

by Patrick L.
(Montreal)

I started an EV conversion project with an old Lincoln SA-200 DC generator from a welding machine.
Before investing more money into it, do you think this will work? I tested the motor on 48 volt and it runs good (no load). Can I use it for regenerative braking?

Hi, Patrick -
Jim Husted from Hi-Torque Electric says:

"Way too much motor. Where do you put the batteries?
The most common mistake people tend to make is put in too SMALL a motor for their conversion; and the second most common mistake? Too LARGE a motor. It’s a little like Goldilocks; you want it just right. 8^)

Everyone is battery limited by definition, so you don’t want to carry more weight than is needed as it could be used for battery weight, or just a lighter, more economically running conversion.

As for re-gen, it’s got some nice attributes, but the most I’ve ever heard of (reliably) is about 10% recovery in energy. This would equate to 22 to 44 miles in range from a 20 to 40 mile conversion. There’s more complexity and costs to do this so each must weigh their own needs.

I would not suggest using a brushed series wound DC motor for re-gen as brush arcing will occur."

- Jim

P.S. from Lynne: About Jim Husted...

He's with a company called Hi-Torque Electric; if you've been around EV-land for long you've already heard of him; he's been building and repairing EV motors since before you were born: )