Thanks for the tip about the ARRL articles. I read all three, and it seems like installing a battery backup is pretty straight forward.

1. Get a deep-cycle 12 volt battery, preferably sealed (how many amp-hours?)

2. Attach a charger like a BatteryTender to the battery. I use one for my motorcycle. It's the kind you can leave on all the time without overcharging the battery.

3. Attach the power leads from the mobile radio to the battery.

Is it as simple as this?

73 - Lynn