I use Zippy batteries from HobbyCity. They are holding up well so far, but only have about 3 flights on each pack so far. When I buy cheap LiPo batteries I aim for about 50% higher current rating than I need, since many of the cheap packs are rated higher than they can actually handle. I'm currently running Zippy 2100mAh 25C and 2200mAh 20C packs in my Stryker. My setup pulls only 26A max, but the packs are rated for 40-50A continuous, so they barely get warm. I also try to pull just 75%-80% of the total charge out of the packs to help prolong their life.