I find these last the best:
Ansmann 5035092 4x AA 2850mAh Rechargable Battery NiMH Digital.
Nice and heavy so good kit.
Those batteries are "ordinary" NiMH rechargeables so will be pretty much flat after 2 weeks whether they're used or not. Good for high-drain applications like Camera Flashes and toys, less good for Keyboards and mice.
Solid reviews for those. Good price too. I'll keep reading. Any point going to an expensive charger or will any do?
I recommend Eneloops, I have about 12 now which I use in my Camera, flash and various torches. They're pretty much invaluable, always ready to go when I need them and delivering every last bit of their capacity years after I bought the first batch.
You don't need a "fancy" charger, but I do recommend you get a "good" charger, which uses
ΔV to detect when the battery is full.
These are the newest Eneloops, product code BK-3MCC. They can be recharged 2100 times before being down to 70% original capacity, and have a nominal
minimum capacity of 1900mAh, but I've never seen a new cell come in at less than 2000mAh.
If you fully discharged and recharged them every day they'd "last" you 5 years and eight months.
In addition to that, they also hold their charge over time, so will still have 70% charge remaining after 5 years of storage.
As for a charger recommendation,
this one purportedly has all the features you want on a "good" NiMH AA charger, and is reasonably priced to boot.
You'll probably get on well if you use yours the same way I use mine; Charge two sets up, put one set in the device and the other in the drawer. When the ones in the device are flat, put the still-charged ones from the drawer into the device, and charge up the flat ones. When they're charged, stick 'em in the drawer. Rinse and repeat.
