While most chargers brag at how fast they can charge their batteries. I prefer buying "smart" and/ or "trickle" chargers. My favourite chargers are from Maha. I like them so much, I own two. If you want C and D cells, Google for the "MH-C808M" model.
When charging multiple batteries, a smart charger will moderate the charge strength to not overcharge
adjacent cells when they don't need it.
A little money saving tip... I no longer buy C and D cells. Instead, for a few extra dollars, I buy adapter sleeves that fit over my AA's. Google for "battery adapter sleeves" for more information.
Also what batteries are you looking at. Ni-cad? NiMh? I prefer getting "low discharge NiMh" or Eneloops. Like Alkaline batteries, low-discharge NiMh lose only 1% of power each month. I use them in my emergency lights with no concerns they will be dead when I needed them.
I realize I'm going off topic, but there is a new rechargeable battery standard called NiZn or Nickel-Zinc. NiZn is mainly sold by PowerGenix, but I'm hearing these souped up batteries have been known to fry the occassional electronic. Instead of 1.2 or 1.25 volts, NiZn batteries are designed to give out more than 1.5v when new (1.8v?)!
