Picked up an A1200 while on vacation about two weeks ago and put CHDK on it the same day

Was itching to try some star trails but my "vacation" was in Cleveland Ohio visiting my parents so I didn't bother trying any star trails. Now I'm back home in Yuma AZ and while I'm really itching to get out into the desert for some good dark skies figured I'd give it a quick try from my backyard first.
Pretty happy with the results! I think I had the overrides set to give a 20 second exposure, though I'm still not totally clear on how to work CHDK so I may have been off on that. I also accidentally left RAW files on which I thought I had disabled so that probably helped eat my batteries a little quicker. Still I was about to get 70 frames off of an almost fresh set of Lithium AA's over about 36 minutes before the batteries were toast.
I did turn off DFS but neglected to shoot any dark frames to use in post. Just stacked them with a free startrails program I found with a quick google search and then a quick levels adjustment in photoshop to tweak the exposure.
Need to pickup some new NiMH's or rig an external power source soon since desert camping season will be starting soon and I'll have some REAL dark skies to work with!