Powerstream UPS
From Wildsong
I got this device to implement a UPS in my car. Originally the car computer was going to be 8track. It will probably be powering my Kenwood mobile radio, a GPS receiver and a BeagleBoneBlack. I have to check the total draw, 10A might be too small.
PST-DC-UPS-1212-10A
www.powerstream.com
http://www.powerstream.com/DC-UPS-1212-10A.htm
The device is marked N13.1, P10. Those are factory settings with this effect:
N13.1 = switches to aux battery when car electrical connection goes below 13.1
P10 = shuts off when aux battery drops to 10V
That means that even though I might have a live connection (always on) to the car, the battery will not be drawn down when the engine is shut off.