Any AA standard size battery can be used. I've used Energizer lithium's without a problem. They last quite a while that's for sure. My mainstay of batteries are a set of high capacity rechargeable cells. Seveal here have mentioned Eneloops which work very well. I've had excellent use of a brand called Ansmann with a capacity of 2850 mAh (mill-amp-hours) and also have a set of 2700 mAh as well. Every time they've out performed the listed in the manual number of photos with rechargeable cells.
Furthermore, together with quality rechargeables (best choice: Sanyo Eneloop) you should use a quality CHARGER - a cheap one with general time control instead of individual electronic control for each rechargeable cannot use their full capacity, and could spoil them in the long run by overheating.
Thank you for the info. I did receive new eneloops and since using them, no probs since. It appears this camera doesn't like the advanced lithiums. I will keep them as emergency back up while overseas just in case there is not a way to recharge the eneloops. I have 12 of the eneloop 2500mAh and a quick charger, so should be OK! Hopefully. I will be in the Serengeti so no place to buy batteries!!
Some have mentioned that it might be due to the fact that rechargeable cells are 1.2 volts vs regulars are 1.5 volts. The camera might be tripping the light due to the difference in volts. I've taken several 30 min videos per take at a wedding just fine while the light blinked all the time. Never had the warm battery issue though neither on this one or the SX120is I had before.