I use Sanyo Eneloop Low Self Discharge batteries with MAHA chargers. There are a few other brands of Low Discharge batteries available. The advantage of the Low Discharge batteries is their internal resistance is lower than the standard NiMh batteries, thus they generate much less heat and will maintain a charge for a much longer period of time. Standard NiMh batteries loose 5% or more of their charge per day. The Low Discharge batteries will hold up to 85% of their charge after 1 year. They also recycle the Speedlight a little faster than the standard NiMh batteries. Good Luck and Enjoy your Nikons!
Eneloops were one of the first Low Self-Discharge batteries on the market, and they have only 2000 msHrs capacity, so they give less flashes per charge than the higher capacity regular NiMH.
However, now there are some newer brands that have 2100 mAhrs, and I just noticed that Ansmann has a brand new one with 2500 mAhrs capacity. It would be interesting to know if it has just as low self discharge characteristics as the Eneloops.
I also use Eneloops, for almost 2 years now, I think.
I have a lot of them, maybe 40+ at the moment. I have 3 SB-800's using the 5th door, so that requires 15. A 2nd set takes me to 30. I do use them for other things, and as "emergency batteries" if I'm out of alkalines for things that should use that type. There quickly comes a point where it's very difficult to manage a large herd of NiMH batteries if they discharge fairly quickly since there is no way to measure the capacity remaining. From a practical point of view I stopped using other types just to simplify this end of the battery problem. When I put a set in a speedlight, I know they will give me 90+ percent of their rated capacity, even if I last charged them months ago.
They also work well in my cordless mice, which run through a pair of AA's in about a month or two. A normal NiMH self-discharges too fast for that application. Also in a Logitech remote that eats a set of batteries in a week with heavy use and monthly with light use. I don't use them in standard remotes and other things where an alkaline will last a year or more.
_________________________________ Neil Nikonians Team My Gallery
I prefer Eneloop or Immedion low self discharge NiMH batteries, depending on whether I am shopping at B&H or Thomas Distributing respectively. I prefer Thomas Distributing for my battery/recharging needs.
Scott Chapin Powder Springs, GA, USA Nikonians Team Member