I'm building a custom radio system for a friend by using a car-audio setup built into a boom-box-like container. I have everything wired up, and it works well enough. In testing though, I've run into an annoyance... the radio system (being designed for use in vehicles) depends on a constant battery power to maintain its settings and memorized channel presets.
Here's how I've hooked up the power so far:
LCD monitor AC adapter (output: 12V, 6A, 72W)
This source is directly connected to the radio via 2.5mm jack.
There is a power switch between the main power hookup for the radio and the source. (The radio wiring harness has provided a memory backup wire which is connected to the source parallel to the main power hookup for the device... this allows you to cut off the radio (and its face lights) while maintaining power consumption necessary to keep the internal memory alive.
I'd like to hook up some batteries parallel to the incoming 12 VDC source current such that the main source can run the system while it's plugged in, but the batteries would operate the system without interruption if the main source were disconnected long enough to move to another wall outlet.
My main questions are:
Can this be done safely and efficiently?
Are there any considerations I've missed (like power regulation or special charger hardware); it seems pretty simple as I'd be using 12v batteries and a 12v source.
If this is feasible, which type of batteries could best handle potentially frequent 80-90% discharge/charge cycles without suffering damage?