> I have a few NiMH batteries 4 to 5 years old, they may have about a hundred
> cycles behind them at most but their capacity is now much less than what it
> used to be.
>SNIP<
> It's so bad that sometimes a freshly recharged pair of NiMH's will last just
> about 10 minutes in my camera or barely suffice to power up a flashlight.

A hundred cycles over 48 months is at the lower end of battery life, but we all know better than to expect the thousands promised on the box. I'd also expect NiMHs to expire on their own after the passage of 4 or 5 years.

Another issue is that NiMHs are 1.2V; alkalines are 1.5V. I've got some devices that expect 1.5V from each cell and they won't operate with rechargeables at 1.2V. I would expect a flashlight to run on 1.2V cells unless it's a high output lamp instead of regular filament. I don't know what LEDs require.

Additionally, high recharge voltages damage cells. If you're using a quick recharger (minutes instead of hours), you're cooking the chemistry, destroying the cells' ability to take and hold a charge.

If all your stuff is four or five years old, I'd considering buying all new high-capacity batteries and a new, modern charger that does not promise 60-minute charging. I think you've gotten all the life out of your old ones.