I suggest reading the write-ups about power supplies in the FAQ: http://www.mp3car.com/vbulletin/advfaq.php
Hi! I'm using car pc based on EPIA M10000, i have faced one problem when i tried to connect it to my car - the system hangs, when i start the car, i have found out that voltage falls down to 8volts, some people suggested to connect an extra battery. I have did so. The battery is 12V 7.5mAh, i also have created a switch, to turn off charge when pc is off, but onc i have forgotten to do so and my battery was overcharged, how to prevent it in future ? i don't want to use switch all the time, it annoys. Thanks in advance!