-Old topic-
I was faced with putting together an external battery pack for my SD600. I've been using a 3 cell version of
http://tinyurl.com/7uo8qp6 for a while now, works great. I can do 12+ hours of time lapse (3 sec interval) easily.
But that battery pack weighs 5.1oz, and I'd like something lighter for backpacking.
I tried a 3 AAA battery holder, with alkaline batteries (4.5V). It worked, but not as long as I had expected. About 4 hours. So I just tried 3 lithium AAA batteries; voltage should be around 5.1V, as new lithium AA or AAA are about 1.7V. It worked! (I have a couple extra SD600 cameras, so I wasn't too concerned if I fried it) The SD600 normally takes a NB-4L internal battery
The time lapse is running right now, about 5 hours duration right now. Cut my weight from 5.1oz to 1.2oz, albeit with a smaller run time, but another set of AAA would be 1oz.
I've had to buy a couple AC power adapters, as the dummy battery doesn't always hold up and I'm cutting off the power plug for the battery.
Let me know if you have any questions.
Cheers
Steve