A while back, I posted here about a battery pack I built out of 8 (4+4 parallel) AA NiMH rechargeables... Realizing I never came back to give results. The lower voltage from them being rechargeable, at full charge came out to be something like 5.2, maybe 5.3 volts, camera took it like a champ for nearly 8 hours doing nothing but Miniature Mode (20x, 720p)... Didn't know at the time that the screen never turns off during Mini-Mode recording (the time lapse feature on my SD770 turns off the screen, wtf was Canon thinking??? But then again, the SD770 also goes for 2 hours in TL mode
), so the screen was on the entire time... I'm betting with the script you are using (turns off the screen after every shot, is shooting pictures rather than continuous video)... This battery pack would probably last you a REALLY long time.
My original posts:
http://chdk.setepontos.com/index.php?topic=6397.msg72885#msg72885 (top of the page and more below)
Also, the pictured 2650mAh Duracell NiMH batteries in that post totally SUCK; they do not hold their charge worth a second thought. Camera literally only lasted 45 minutes with those things... AFTER a full charge! Needless to say, they were taken back to the store and refunded. However - I also have 8 Duracell "PreCharged" 2000mAh batteries that I generally use in my SX20.. These batteries totally ROCK. They're the ones I used that lasted a full 8 hours. Just a heads up
And unfortunately I can't try your script to see how long it would last because some kid knocked my SX230 off a counter top and now it's dead. Hoping to get a new one soon though!!! I loved that little camera..