This battery pack replaces the earlier version (ref 9798). This battery is more powerful (it delivers a current of 2100 mAH) and equipped with a DC plug.
This battery for Lego Mindstorms NXT is an interesting alternative to conventional AA batteries.
The estimated charging time is 4 to 5 hours.
It requires the power cord (ref 8887) which is sold separately.
Battery Reference: 9693