Outback Power Systems FLEXpower ONE One Fully Pre-Wired Single Inverter System Installation Manual - Manual (Page 57)

Specifications
900-0095-01-00 Rev A
55
 Refrigerators and ice-makers typically run only about 1/3 of the time, therefore, the running
wattage is 1/3 of the total wattage of the appliance. Divide the total wattage of the appliance by 3
when determining the battery requirements.
Calculating Amp-Hours
To determine the amp-hours that will be consumed, list the anticipated loads and the length of time
they will operate. Use the specifications noted on the labels of each AC load that is to be connected to
the system. Determine the number of hours per day and the number of days during the week that the
load will be used.
Use the worksheet on page 56 to list the respective values and calculate the amp-hour requirement.
In summary, to calculate the amp-hour requirements:
1. Determine the loads the system will power and enter their wattage.
2. Determine the number of hours (or decimal portion of hours) the appliance is used each day.
3. Determine the number of days the appliance will be used during the week.
4. Multiply Hours x Days for each load identified to determine the watt-hours per week.
5. Add the total watt-hours per week for all loads then divide by 7 to obtain the average total
watt-hours per day.
6. Divide the total average per day by the DC nominal voltage.
This figure represents the average amp-hours per day that will be used.