Quote:
Originally Posted by Mr Sunshine
We take along a little ceramic heater, and it does a nice job with an electric hookup. I added a 1000W inverter, but haven't done the math as to how long the batteries could run the heater.
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Not very long unless you have a lot of batteries.
The typical RV battery has a capacity of roughly 1 kW-hour. If you have two of them that's roughly 2 kW-hours to empty based on 20-hour rate. Drain them faster and they provide even less energy.
If you only drain them down to around 50% to preserve battery life, then you can count on 1 kW-hour of useable energy from the 2 batteries. That suggests a 1 kW heater will deplete the two batteries in less than an hour.
I've looked at these kinds of numbers for years. My goal was to run a small Air Conditioner (that only uses 500 watts) for 6 to 8 hours. And using standard batteries it would take about 8 of them -- roughly 500+ pounds worth of lead. It's physically doable but not too practical.
With a heater that pulls twice as much juice (1000 vs 500 watts), you'd need even more battery bank capacity to heat through a single night.