Chevy454 wrote:
This item prevents your thermoelectric cooer from draining your car
battery to the point where you can not start your car:
http://koolatrononline.stores.yahoo....ery-saver.html

Can something like this be easily homebrewed from a couple of 30/40
amp horn relays and a couple of pots? That would permit its use for
the same purpose in mobile QRO radio.

I tested one and it open the circuit at 11.5V and closes it again at
12.8V. The dead zone is needed to prevent cycling.

Ken KC2JDY

You can get a smart charger for less than that, and just keep your
battery topped-off at all times.