I have several chargers, including the Maha MH-C401fs and the MH-C204. Both are good chargers, but I prefer the 401 because it has four independent charging circuits and the 204 has only two. (It can only charge batteries in matched pairs and batteries become mismatched over time. Or your headlamp uses three... Independent circuits are better because the charge is tailored for each battery individually.)
I also have a Lacrosse BC-900 (the Maha MH-C9000 is similar). It is similar to the C401 with the additional capability of measuring the capacity of the cells. This can be useful after you have had some batteries for a while and wish to evaluate and sort out those that are getting weak. (I also label all my batteries so I can use them in matched groups and keep track of their health.)
The MH-C401fs is a good basic charger. A good "starter' charger (and probably the one that I use most often).
"Standard" AA cells have a capacity ~2600 mAh (AAA ~900 mAh) and low-discharge AA cells have a capacity ~2000 mAh (AAA ~800 mAh). I have some of each kind, but will probably be standardizing on the low-discharge cells in the future. (Standard cells will discharge significantly faster while sitting on the shelf than low-discharge cells. However, if you top off the charge shortly before using them, the standard cells work fine.)
FWIW, I use Sanyo Eneloops for my low-discharge. They pretty much set the standard...
Trickle charging is
not a good way to charge or store NiMH cells. They charge best at a several hour charge rate using a "smart" charger. (A non-smart charger is likely to damage the cells.) Things that damage NiMH cells: overcharging, overheating when charging (typically by charging too fast), discharging to zero or reverse charging (by trying to get the last bit of use out of them). It is good to charge them frequently (there is no need to discharge them fully)--if charged properly using a good smart charger, they do not develop a memory effect. (Memory effect is primarily seen in NiCad cells.)
Many of the chargers run on 12 volts and come with (or offer) a 12V automotive cord. Many also come with (or offer) international power supplies (120-240 V, 50-60 Hz).
NiMH batteries are
much better than alkaline batteries in digital cameras. Digital cameras tend to draw high currents for short periods of time--NiMH is good at this, alkaline is poor at best. (NiCads, lithium non-rechargeables, and Lion (lithium ion) rechargeables also work well in this kind of service.)
I use NiMH batteries in my camera (at least the one that will take AA cells...), headlamps, GPS, bike lights, radios, etc. (Alkalines are better for smoke and CO2 detectors, clocks, and other indoor low-drain applications.)
A good place to buy NiMH batteries and chargers:
http://www.thomasdistributing.com
Professional quality info on NiMH batteries:
http://www.batteryuniversity.com/index.htm
http://data.energizer.com/
This general topic has been addressed a number of times in the past: just search on NiMH and lots of relevant threads will appear.
Standard caveat: I have no connection with any of the companies mentioned above. Just a user or customer.
Doug
