I think its good to get those chargers with refresh functions.. I uses an external flash, and most times, I can't deplete the batteries completely. Think there is a memory effect if its not completely drained before charging again. I usually end up depleting the batteries by putting it in my discman and using it till the power drains totally..
but sanyo is good.. i have 3 sets of sanyo 2300mAH batteries and are very happy with them..