Thanks for all the replies, I think I'll just stick to the 36V pack and run
the motors at 33% with a separate battery for the electronics. Seems to be
the easiest and should work out just fine.
There is a company that makes a programmable power supply where you can tap off about 3 different voltages from one power pack (set of batteries)
Unfortunately I couldn't find them again on the web. But they did have ads in Robot magazine and probably Nuts'n'Volts, too. The devices were pricey, though, from $50 to $200 or so. Depends on your budget & needs. Separate batteries would certainly be cheaper!
Not much help I guess but if you flip thru Robot mag you might see who I am talking about.
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