Intellect 2S 450mAh 25C Li-Po Intellect O-IT2S1P045025A ompetition indoor flying. With a 450mAh capacity and 25C performance there is over 11A of constant current available. With most F3P models pulling around 6A, there is plenty in reserve.
When you add that to the compact dimensions and low weight and then look at the price, its hard to see how that can be bettered.