Motion-sensitive Camera update

The camera read "low battery" after only a couple of days and very few pictures. This is very disappointing, as the four name brand alkaline C batteries I put in cost six dollars. Am currently mulling my options. Rechargeables? High upfront cost and will probably need to change every two days. There is a connector for a "12 volt lead acid" battery. I am not really sure if this is the old 12 volt batteries from my youth, that many flashlights used. Plus I need to order the cable from the vendor www.nativeoutdoors.com.

Turns out the camera is a Sunplus, which makes generic cameras and such that other companies re-label as their own. The Sunplus web-site doesn't speak much English.