Build your own battery pack for your APF
If you want to build mobile systems, you can power on your APF with a self made rechargeable battery pack.
- a 6xAA battery container. Example:  and 
- a power supply connector. Example:  (2,5 mm diameter)
- 6 rechargeable AA batteries (6 x 1,2V -> 7,2V)
- Solder the connector to the battery container with respect of the polarity: + is in the middle.
- That's it ;-)