P = V**2/R. with V fixed at 12V DC, rather than say 120 VAC (rms) for
house current, R should be 1% as large to achieve the same power at 12
VDC. and please don't start another ohm's law thread.

On Fri, 16 Feb 2007 15:37:30 -0500, Geza Polony <gezapolony@SBCGLOBAL.NET>
wrote:

>I got one of those trucker's 12 volt electric blankets for my daughter's
>Christmas present. (OK, a true "go Dad" kind of present.)  Trying it out,
we
>found that even on full, it only gets kind of warm--nothing like the ones
>you plug into the wall. After you use it, you can't tell if you warmed it
up
>or it warmed you up. Is ours defective? Dunno. Little like putting a cold
>6-pack into a Dometic: what's cooling what?
>
>BTW, the blanket has a shutoff for 15 or 30 minutes, so you can't leave it
>running that long without resetting. Very little electrical resistance
>IIRC--maybe that's why it doesn't get hot.
>
>The 12 volt compressors work great but will overheat if you keep them on
>long enough to inflate a nine foot diameter swimming pool. That's like,
all day.