I built a battery box with a voltage regulator I bought on eBay for $5. I have a 12V SLA in the box and run the 12V into the regulator then set the output voltage to 6.5V and wired up a spartan external power cable and a Ridgetec output cable. I can run both a 6V and a 12V camera using the same set up. I also use a solar power controller and run a 30W solar panel on the system.