ChargeGuards are frequently listed on eBay, probably by radio techs that are stripping police cars and
ambulances for selling, and can usually be had for around $25. They provide a protected 12v source from
your battery, switched on by your ignition. (or a few other options) It's a good way to precent your radio
from killing your battery. One configuration turns on shortly after you start your car, and then turns off
5 minutes after you shut your car off. Includes manual override for timer also.
Ignition sense can be unreliable, especially in cold weather. Configuring it to operate from an accessory
line will work more reliably.
