Originally Posted by BES
NNNOOOOOOOO!!!!!! You're going to abuse, if not ruin, your rechargeable batteries.
Fast charging is the death of rechargeables. Slow charging is much better. That's why the La Crosse chargers default to their slowest charge rate, and why the BC-900 isn't worth the money over the BC-700.
Buy more batteries, so you can make it through a shoot without having to charge the batteries you own. Buy enough chargers so you can get enough batteries recharged in time for the next shoot. But don't buy rapid chargers to make up for a lack of batteries or chargers.
I have six 4xAA chargers on my charging table. I'll probably buy two more before our spring "event season". I have 48 Eneloop AAs, with 48 more coming in this week, and about 40 of another kind of rechargeables that's being "assigned" to side duty in Pocket Wizards and such. With four 580s and two external battery packs, I have 32 Eneloops loaded in our gear, so 96 gives us the initial load plus two complete swaps. That'll be enough for a while. We're running tight today though; I have 24 batteries charging at the second-slowest speed in the hopes that they'll be done before bedtime and I can load up another 24 tonight to have 48 ready for tomorrow.