This battery system models the relationship between battery loads and available time based on Amp-Hours (unit of electrical charge). The battery has 120 Amp-Hours available and amp draw from individual loads can be changed to determine battery life.
The Amp-Hour rating tells you how much amperage is available when discharged evenly over a period. The amp hour rating is cumulative, so in order to know how many constant amps the battery will output for 10 hours, you have to divide the amp-hour rating by 10. Example: If a battery has an amp-hour rating of 120, dividing by 10 = 12.0 amps. Such a battery can carry a 12.0 amp load for 10 hours before dropping to the fully discharged level, at which point the battery needs to be recharged.
This model will simulate battery life with both steady and variable loads.