I have a Cobra DMC300, which is an exact copy of that camera (well, one of them is a copy) :), and there isn't any setting for length of filming -- they're pretty much keep shooting until battery or memory has run out. I have noticed that an excessive jar, from a crash for example, can shut the camera off prematurely which also seems to kill/lose the video it was taking completely. You might want to make sure the camera isn't getting jarred around too much. Other than the jarring problem, mine stays on till my SD card fills up or I shut it off. Good luck!

I have the same clone. Mine was packaged as "5 in 1" on the bubble pack. Same housing... same button array... bought at LHS in OKC. While I can get some acceptable video from time to time... here's some hard won tips I've found with mine. (1) When powering up in very bright sunlight... SHIELD the lens in your palm or next to your chest. If not... expect a GREEN shade to your entire video footage. Sometimes even that does not work..?? Main point... make sure the lens is in a shaded situation during power-up when outside. (2) When attempting to charge this camera through your USB... take the memory card OUT..!! Mine will act completely dead... no green light... no red light... nothing until mem card has been removed. I use a SD 1 Gig for your reference. Once you have at least a 1 hour charge on it... then re-install the mem card and I generally add another 2-3 hours to the charge. My version has a ON/OFF slide switch on the edge that you turn off once you're finished charging. That is supposed to save any draw on the Lipo when camera not is use. Found all this out by trial and error... no manual info about this that I found anywhere.