Best AA lithium batteries for time lapse?

Hello everyone,

I have a bit of a project that I am in need of help. We have a point and shoot cam that will be experiencing cold temperatures and needs to run as long as it possibly can on 2 AA batteries.

I assume Lithium's are the best bet. Can anyone recommend any brand? There seems to be lots of them and lots of variations between them, ultimate, extreme, awesome, advanced etc...

I'd choose one of those that has low self discharge (those that can hold 75% of the charge for pretty much a year) and that are specced at as high mAh as possible. Like 2800mAh or somewhere in that range.
And ofcourse any brand that is well known.

How cold and how long? Can the camera accept external power? If so, you could use a UPS.

Try it out with normal batteries, you might be surprised at how long they'll last.

That being said, for extensive and severe cold, the camera is usually rigged up to a battery pack thats insulated to help keep the warmth as long as possible.

A simple hack would insert a dummy sort of battery into the camera, that runs out to a bigger external pack of batteries wrapped with some insulation.

The camera can accept external power, its the standard little usb plug found on the Canon P&S's

Temp would be from 0 to -40 Celsius. Time would only be for about 3-5 hours and running CHDK and taking a picture every 10-15 seconds or so.

I was looking into the dummy batteries but couldn't really find any solid solution out there. The time its going to be running for is not long but the batteries have to last through a couple thousand pictures and the cold.

http://www.climber.org​/gear/batteries.html

Section halfway down the page about battery life. Cold weather is discussed. I think as long as you get a reputable brand lithium battery you will be fine. According this this they do not outlast alkalines, but for cold weather, they will do better. That was my interpretation anyhow...

Best of luck...