Okay so I already have some AA's that I use in my digital camera and they work great. They are Monster Power and I have a Monster Power digital charger. Now I wanted to get some AAA's for my walkman but instead of forking out $19.99 for Monster Power AAA's I got some Energizer ones (also NiMH). I assumed I would be able to charge them in my monster NiMN charger. Well after the AAA's died the first time I popped them in the Monster charger and a few hours later the light changed to green indicating full charge. Put them in the walkman and a couple minutes later they're dead. I guess they didn't charge in the Monster charger. WTH do I have to buy the energizer charger too . I knew I should have just bought the Monster ones in the first place

 

If your charger has a "clearing" mode where it drains the battery, then try that.

Lots of good faq's here: www.thomas-distributing.com