As I mentioned in another post I guess I have to go back to school to get the various mechanical and electrical relationships straight in my head. Fortunately I have the University of the Internet available for my extension classes. I'll be looking, but can you point me at any sites that have a good explanation of an appropriate controller? Thanks for the help now and in the future.

try this site and see if it helps...
Battery Motors and Controllers - FAQs Part 1

Ah, here is the motor. I just looked it up. Its a permanent magnet. These are a bit more efficient (in general) than series or shunt wound motors. I'm not sure what to think of its torque rating though. Seems very low. I'm thinking 27 ft/lbs sounds better.

https://www.surpluscenter.com/item.a...1&item=10-2424

Daox, oops, most of my questions were answered in the battery motors controllersFAQ's
which I read after opening this. Sorry.

Well folks,the electric mower project just went on indefinite hold when the transaxle froze up while mowing the back yard today. I had made some temporary repairs last year while unemployed, so I wasn't overly surprised when it went. Parts for the peerless 801 transaxle in this mower are few and far between. I can replace it with a new peerless 820 which is still available, but I have to think hard about adding another $300-$500 to the cost, so for now the project is shelved while I decide whether to go forward or junk the old girl. After all, it just turned 31 years old, and has given me 23 years of good service, so maybe it's time to move on. Bottom line, I'll let you know if I decide to continue.

Check out freecycle.org. Thats how I got my mower for free!