Arduino LiPo/Solar power question

Hi,

I have a remote that I am using for my camera. The remote communicates with my camera using an IR LED through the camera's IR port. Right now I am using an Arduino Uno 5V with rechargeable AA batteries. What would be the best way to increase battery life? Does anyone have experience with the products below? Is LiPo the way to go?

http://www.seeedstudio.com/depot/solar-charger-shield-v2-p-914.html?cPath=132_134 http://www.seeedstudio.com/depot/lipo-rider-p-710.html

Thanks :)

"What would be the best way to increase battery life?"

Simplest answer is to use it less! Then I'd go with slowing down the clock frequency and running a lower voltage. Try a 3.3V 8 MHz promini running off 3.7V LiPo direct into VCC pin (no regulator), or build up a minimal component clone & run at 4 MHz.

100mA will charge a LiPo nicely with a MAX1811 type charge control chip, or a dual input chip like MAX1555. 500mA from USB port will do nicely too.