Shun Cheung , Apr 12, 2008; 01:08 p.m.
Mike, take a look at page 19 in the SB-800 manual. Lithium batteries provide the slowest flash recycle time on the SB-800, worse than Alkalines. IMO, NiMH rechargable AAs is the best choice and I get 2900mAH types from B&H.
Additionally, I highly recommend the SD-8A external battery pack to speed up the recycle time. It takes an additional 6 AA batteries and speeds up the recycle time to 1 to 2 seconds. The SD-8A was very hard to find until a few months ago. I like it so much that I actually bought a second one as a backup.