I agree with what has been said. A 4.8V 4 cell 600 mAh battery is plenty for your current needs. At the same time I will tell you that there is not much difference in cost $20 vs $25) between that and a 5 cell 2000 mAh 6.0V Nimh battery pack. The larger pack will give you slightly quicker servo response time, and more torque. While niether of those may mean much now, they might when you move up to a larger plane. After reading that bettery problems are the second leading cause of crashes, I decided to replace all of my 600 mah batteries with 2000 mah packs. In addition to more torque and quicker response time the larger pack will give you significantly more flying time. Since switching mine I rarely use more than 10% of the capacity, which gives me a warm, fuzzy feeling. Just my two cents.