Promax batteries?

[Flatty]

I have 2 of these batteries in my Scorpion, but they only last 15-20 minutes.... http://www.globalhobby.com/public/gallery/233011.asp Can you tellme if this is normal? I really want a longer life, with this small size. Are there any other options with a battery this size?

thanks
Dima

 

[relic1]

look into elite 1500 2/3a packs same size with a little more capacity