As Shawn said, a 6055 uses a hair under 1amp per hour so a 24ahr 12V battery for example would run the pump for about 27-28hrs, a 6105 uses a bit more than 1 amp at 12V so in the same example a 24ahr battery lasts about 20hrs. At 24V the amps are about the same, slightly higher but not much about 1.2 for each pump.