09
Example
A Microwave oven
= 700 Watts
12V battery bank
700 Watts to run microwave oven using the batteries as
if it was a 12VDC microwave requires 58 Amps
700 Watts / 12 Volts = 58 Amps
Now that amps have been determined, the amp-hours
need to be determined. The microwave will be used for
approximately 3 hours a day.
58 Amps * 3 hours =
174 Ah
At least a 174 Ah battery must be selected in order to use the 700-Watt microwave at 3
hours a day. However, determining a battery size is also dependent on the battery that
is able to handle repeated discharge/charge cycles.
Load Operation = 3 hours
Determine the amount of Watts (Amps * Volts) for the load, and how long the load
needs to operate—
each electrical appliance has technical specifications indicating
the watts, or the volts and amps required for operation.
Estimate load run-time—
Battery size depends on load watts and run-time. Most loads
are not constant, so estimation is very important.
Utilize the formula Watts = Volts * Amps
Determine Amps used for how many hours – Amp-hour (Ah)
Sizing a Battery Bank
For this Renogy inverter, the battery bank will be 12 volts direct current (12 VDC)
This is just an example. Actual quantities vary by battery capacity and rates
of discharge.
NOTE
To power the microwave in the example, the user must use an inverter that is
at least 1000 watts, if not more.
NOTE
