Run stove on car inverter?

[SwineFlue]

somebody check my math here...

Looks good for your DC-motor stove. Most of us have variable-speed AC motors, where the power factor can be as low as 0.5 and effectively double the electrical load. My stove uses under 100 Watts, but is drawing 1.2 Amps.

Looking at it in terms of current draw, 1.2 Amps at 120 Volts is equivalent to 12 Amps at 12 Volts. Now add that 20% inverter loss and it's around 15 Amps to supply a small stove. So the car's alternator would need to provide 15 Amps in addition to the vehicle's normal electrical load and recharging the battery. That's a heavy load on the alternator at a 600rpm (or whatever) idle speed.

 

[briansol]

You could always prep your car to have a different pulley size to 'overdrive' the alt. but of course, that would kill it for daily driving at higher rpm.

 

[Madcodger]

Your numbers seem about right but..... If you measured the input power with AC input, your stove will do better with DC input. The AC power supply has it's inefficiency too. When I measured the DC input to my MVAE I saw it vary from 18 to 24 W over a short interval (one hour). The reason for the variability is that the stove adjusts blower speeds as needed to maintain an appropriate burn level (automatic mode).
With minimal off time for required cleaning I was able to get over two days of use on a 110 Ahr battery during the aftermath of a 2012 storm. Now I remember that although it was uncomfortable, the air temperatures weren't that bad so the stove wasn't running full force during that two days.

Most other stoves can't manage this kind of miserly behavior and their battery life will be shorter.

Those wattages seem reasonable, Harvey, and you're right - some off time will extend battery life. I try to plan for a fairly cold day to be safe, so we're all in the same ballpark with estimates, I think.

 

[gfreek]

So the car's alternator would need to provide 15 Amps in addition to the vehicle's normal electrical load and recharging the battery. That's a heavy load on the alternator at a 600rpm (or whatever) idle speed.

I wonder what would be the vehicle's normal electrical load, say with no accessories on??

 

[SwineFlue]

I wonder what would be the vehicle's normal electrical load, say with no accessories on??

Don't know, but in a "loaded" car there's got to be some reserve available if you turn off those lights/defrosters/stereo/AC/heated seats/etc. Also, some towing packages include heavy duty alternators.

 

[gfreek]

This is what I have:
http://www.hodgesmarine.com/Xantrex-Prowatt-Sw600-600-Watt-True-Sinewave-Inver-p/xan806-1206.htm

 

[KC7NO]

Does anyone make a DC motor that can replace the AC combustion motor in a Harman .... the AC motor itself looks common ...
(and the auger motor too)