Recently I started to notice my Maha Powerex batteries were starting to run out of juice quicker so I figured it was just time to replace them, no biggie, hat is until I realized my Maha charger also took a crap.
Basically I would come back after a few hours of charging, and realized that the charger could no longer regulate the power-flow anymore, which led to some extreme overheating to the point that the LCD screen on the charger started to distort, and the batteries were incredibly hot to the touch (imagine me playing hot potato with AA batteries as I tried prying them out of the charger).
Finally after a few weeks of getting by on standard copper batteries from the store, I gave in and purchased a new set of batteries, and a new charger.
Batteries: Eneloop Rechargable
Charger: La Crosse BC-700
Note: I have nothing against the Powerex batteries, they were great and lasted a few years of abusive use, but I found a really good deal on the Eneloops so I had to jump on them.