Battery Bank Calculator
1) Enter the running watts (Amps x Volts = Watts) you plan to support with the battery backup
2) Enter your desired runtime or that amount of battery support you are going to need (use a decimal for times less than 1 hour Example: 15 mins enter .25).
The result will be the number of battery amp hours at 12 volts DC that will be needed to support the desired load.
The ups battery bank calculation and sizing formula on this page is based on typical 12 volt VRLA batteries that have been rated on a 20 hour dischage.