Midwest Motion Products released the Model No. MMP-S28-400A GP81-046 BR-015 gear motor, which accepts any 24-volt DC source, including battery power.
According to the companys press release, the gearmotor measures 3.2" maximum diameter by 13.3" long and has a keyed output shaft of 19 mm diameter by 49 mm long.
Mounting is accomplished with four $BEG(Bace mount$B!&(BM-6 threaded holes, equally spaced on a 65 mm bore circle diameter.