before we bought the batteries & charger, we did pretty exhaustive research. We were looking for batteries with the following qualities:
- rechargeable
- a high mAh for a fast charge on the flash (looked for 2700)
- NiMH (best rechargeable batteries)
we ended up choosing the batteries I linked to previously, and
this charger.
Rechargeables tend to have better life if you fully charge and discharge them a few times.
check this site out for a pretty good overview of batteries:
http://michaelbluejay.com/batteries/