Using the Apple Battery Charger with non-Apple batteries The Apple Battery Charger's product description page states:


  The Apple Battery Charger can recharge one or two batteries at a time. It's optimized for Apple-supplied batteries and it works with AA NiMH batteries from other companies, too.


Does anyone know the required specifications for using non-Apple batteries? 

The Apple supplied batteries are AA Ni-MH Min. 1900 mAh 1.2V HR6.

I have some Powerex AA Ni-MH Min. 2500 mAh 1.2V, so I'm wondering if they are compatible. I'm also curious what other non-Apple batteries are compatible.
Apple Batteries are Rebranded Sanyo Batteries

According to engadget, the Apple supplied batteries are actually Sanyo Eneloop HR-3UTG, so it appears that's one option for buying additional batteries to use with the Apple Battery Charger.

Powerex Batteries Don't Work

According to the Apple Battery Charger Manual,


  
  Flashing Amber: May indicate any of the following conditions:
  
  The batteries haven’t been properly installed in the charger.
  An unsupported type of battery is in the charger.
  The batteries may be faulty or damaged and should be replaced.
  
  


With that information, I tried charging the Powerex 2500 and 2700 batteries but received a flashing amber light.

Looks like I need to buy some of the Sanyo Eneloop HR-3UTG batteries.