Battery backup

[GregW]

I'm thinking about making a battery back up from a 12v car battery hooked up to an 400 watt power inverter to power a mj1200 and possibly a 100w heater. I'm thinking I wont need the heater since I have natural gas and I could heat water to keep the tank warm should the power go out. (My gas water heater should work without electricity, right?)

Anyway, my question is: How long could the battery last running just a mj1200. I plan on keeping the battery hooked up to a solar trickle charger when it's not in use.





PS - Please don't tell my wife - she'll want to plug her hair drying into it.

 

[panmanmatt]

Most gas hot water heaters have an electronic ignition system so they won't work during a power outage. If you have a gas stove you can manually light those burners and heat water or cook that way.

As for the battery, I'd opt for a deep cycle marine style battery. They are more expensive but can handle being drained and recharged more so than a car battery can. As for the run time, that would depend on the size of the battery but I think you'd get a couple hours with just an MJ 1200 running. Plus if it has a solar trickle charger hooked to it, it can be recharged during the day if the outage lasts that long.

 

[GregW]

Thanks Matt. I might also use a timer to have it run on and off maybe 5 minutes at a time.

 

[panmanmatt]

I'd go more of 15-20 minute cycles. 5 minutes may be too much for the pump to handle.

 

[redfishbluefish]

Most gas hot water heaters have an electronic ignition system so they won't work during a power outage. If you have a gas stove you can manually light those burners and heat water or cook that way.

I respectfully must disagree.  If you have a conventional gas water heater (the old school kind that ONLY has a gas line attacked to it … most common in residential homes), then it functions off of a pilot light.  No electricity is needed.  Just be aware that some of the newer high efficiency heaters do have electronic igniters and also may have electronic exhausts where electricity is needed.  It should be obvious in the electrical crap going to the igniter (bottom of the tank) and in the exhaust pipe.

In regard to gas stoves, unfortunately it is just the opposite.  The stoves of 20 years ago simply used a pilot light.  They would work regardless of electricity.   The newer stoves today all are computer controlled. Believe me I know it having replaced that board in about 15 stoves.  And it’s amazing in that it always goes on a holiday when you are cooking for 30 people.   If you have no power, you have no stove/oven.