Use An Inverter
FORMULA DC to AC via an Inverter
Formulas and Examples for 12- & 24-Volt DC Systems
This “rule of thumb” is intended as a general guide for estimating the DC amps required operating a DC to AC inverter. Since the calculations yield approximate values, an appropriate safety factor should be considered when designing and specifying system components, such as wire, size and length. This basically means “oversize your system.”
12-Volt DC Systems
Formula: 12-volt inverters require approximately ten 10 amps DC input for each 100 watts output power used to operate an AC load.
Example: How many DC amps will a 12-volt inverter require to operate three 500-watt quartz lights, or a 1500-watt electric heater?
Answer:
- 1) Total watts = 1500
- 2) 1500 watts/100 (from formula) = 15
- 3) 15 X 10 amps (from formula) = 150 amps.
This is the DC current the inverter will use to operate the 1500-watt load. Note: If these 150 amps are drawn from the battery for one hour, 150 amp hours of battery power will be used.
To support 150 amp hours of battery power, 300 amps of battery capacity should be used for maximum battery life and performance.
24-Volt DC Systems
Formula: 24-volt inverters require approximately 5 amps DC input for each 100 watts output power used to operate an AC load.
Example: How many DC amps will a 24-volt inverter require to operate three 500-watt quartz lights, or a 1500-watt electric heater?
Answer:
- 1) Total watts = 1500
- 2) 1500 watts/100 (from formula) = 15
- 3) 15 X 5 amps (from formula) = 75 amps.
This is the DC current the inverter will use to operate the 1500-watt load. Note: If these 75 amps are drawn from the battery for one hour, 75 amp hours of battery power will be used.
To support 75 amp hours of battery power, 150 amps of battery capacity should be used for maximum battery life and performance.
