DC to AC

[old-git]

Is there any, simple, way to work out how much power can be provided by a car battery when run through an inverter?

For example. How long would an 18Ah, CCA 265A, Peak 680A battery last if I wanted 3Kw AC?

Looking to power an AC motor with a car battery for approx 15 seconds.

 

[HDi fun]

3kW at twelve volts is approximately 250amps though consider power factor (later). Assuming the battery is robust enough to stand up to 250A for 15 seconds (and with a 680A peak current rating it should be).

What is the Ampere-hour rating of the battery?

You'll also need a decent inverter with a good quality sinusoidal output waveform otherwise you're going to have huge problems with electrical noise.

Bear in mind too that the charging system needs to be able to replenish the battery sufficient quickly if the 15 second applications are going to be happening frequently.

Bear in mind that a 3kW motor will draw significantly more under acceleration to rated speed and load. There's also the issue of AC power factor. kW isn't necessarily the same as kVA with reactive loads such as motors.

Let's have a look at the motor's specs - is it single phase or three phase?

 

[old-git]

18A/H
7.9Kg
Charging Amps 680

That's all it says on the label.

Fan will be single phase.

Usage will be well spaced out so charging isn't an issue.