set database: k9833 rechargeable battery set

theme: technic, mindstorm NXT
year: 2007
pieces: 2
prices: us$55

minifigs: none
additional accessories for mindstorm NXT.

substitute for aa batteries.

included 9798 rechargeable battery and 9833 transformer.

rechargeable battery is lithium.

transformer is 9v and can be plug into ac outlet for recharging battery.
overall design is good.