http://dpanswers.com/content/equip_batteries.php
There is alot of conflicting information out about battery care so if you have ever found yourself running flat half way through a wedding ceremony, you may want to give check it out.
Speaking of power, there are a few times i'm sure we could all do with a bit extra juice so decided to give one of these babies ago. She holds 6 batteres and runs both the SB800 and 900s. So far it seems to do the job rather well. The only downside I suppose is it increases my relience on those blasted AAs