DougPaul said:
I also picked up a 12-volt inverter so I could power the refrig from my car if need be.
Didn't know that could be done. Got link for that.
I'm assuming the car is running? Can you run lights or a furnace with that as well if you alternated plugging them in?
I got the idea from the article "Power Inverters offer backup in a blackout" in the June 2012 issue of Consumer Reports. I can't find the article online, but here is a similar (and more detailed) article:
http://www.consumerreports.org/cro/...-power-inverter-replace-a-generator/index.htm.
I picked up a PowerBright PW1100-12. (There are other brands.) This produces a stepped waveform which is less efficient than a sine wave. (Normal AC power is a sine wave.)
* Yes, you will have to keep the car running--otherwise you risk discharging the battery which will both prevent you from starting the car and may also damage the battery. (You should use a deep-discharge battery for battery backup service, not a car (starting) battery.)
* Motors require up to 10x the running power to start. The inverter must be capable of supplying the starting surge. For my refrigertor:
~120 watts from AC lines (sine wave)
~ 150+ AC watts from the inverter (~350 Volt-Amps)
~ Assuming the worst-case 350 VA, this requires 40-50 amps at 12V
- My car alternator is rated at 90A (and the car motor will require some current).
- (All these numbers are my recollection of actual AC measurements. I couldn't measure the starting surge or the DC currents, but a 400W inverter could not start the motor.)
* You will have to check the ratings to see what else you can run and don't forget the starting surge if motors are involved. (Use hiking headlamps rather than AC lights--much more efficient.) Also, some electronic devices don't like stepped waveforms.
* If you want to run multiple devices, you may have to run them one-at-a-time.
Personally, I wouldn't use inverter for a house heater--it likely has big motors and is permanently wired into the house wiring . If you want to run your house off a generator, get a 5-10KW stand-alone generator and get it professionally connected into your house wiring.
Safety Note: You cannot just connect a generator or inverter into your house wiring--you may shock linemen working on the power lines, lose power out to the grid, and/or have your generator destroyed when the power comes on. (Professional installation uses a switch which disconnects your house wiring from the power lines when using the generator.)
Doug