This chart shows the relationship between the number of steps climbed up and back down again and the battery voltage on the Hercules machines. Notice that after you have climbed about 78 steps all the way up and back down again the voltage begins to drop. It drops very gently losing about one volt per flight of steps. As the battery voltage drops, the Hercules machine climbs slower and slower and this gives the operator a good warning that he needs to recharge his battery.

Because of the energy efficient gearbox on the Hercules machines, even with a totally dead battery although you may not have enough power to climb all the way UP the stairway, you will always have enough power to climb back DOWN the stairway. The standard battery included with the Hercules machines is a 17 amp per hour battery.