Well let's see.
If an electric blanket uses 180 watts and you sleep 8 hours that is 1440
watts. Assuming a 75% duty cycle if it is very cold but you have other
blankets over the heater that is 1080 watts. The average inverter is 80%
efficient so that brings it up to 1296, lets say the original 1440 to be
liberal. That is 1440 watthours. If 1440 / 12 volts =120 amp hours is true,
and I think it is then the average battery should do it.
Actually having a 12 volt electric blanket would be very cool....er, warm I
mean. An added bonus is that you don't have the AC next to your bod with the
DC thereby preventing cancer.(if you believe the fearmongers)
Where can I get one?

Rachel http://www.gnarlodious.com

 Entity Royston, Jerry spoke thus:

> I was thinking about getting an electric blanket to accomplish this.  Of
> course you would need an electrical hookup.  Has anyone else used electric
> blankets in their Westy?  How long would it take to run a battery down with
> one on all night?
>
> Gerry Royston
> Bethesda, MD
> '87 Westy