I've made a tracer for a lathe using a car wiper motor and more recently
a vibrating table for refractory castable material like concrete using a
car cooling fan motor, both these were 12V and used occasionally for
short periods so I just ran them off the 12V car battery. The wiper
motor would run off a 12V power supply I made but as the use was
occasional it was easier to charge a battery and use that as the supply.
The same was true of the vibrator, it would run for a couple of minutes
before tripping a 10 amp battery charger but was just easier to use off
a battery and use the charger to charge it. So far as a recent project
the vibrating table has been used to cast a 39kg glass furnace gathering
port which probably required running the table for about 15 minutes,
the 44 Ahr car battery seemed fine.

mlcorson wrote:

I recently dumpster dove for a couple of 24 volt 400-600 (estimated)
Watt, 3000rpm motors with controller off a Ranger II (1999) wheel
chair. They each have a gear box that should be either 18:1 or 24:1.
Would these be good for converting to a variable speed drill press? I
need a power source as these ran off 2 12v car size batteries. I
haven't been able to determine the exact specs of the motors as the
manufacturer is not cooperating, and the motors have a minimal amount
of information. Any suggestions on obtaining a reasonably priced power
source? How many amps?
-Mike