Great job! You seem to have the plane trimmed well and your take offs were pretty smooth and not too steep.
As far as the cheap battery, did you make sure you had the same "C" rating on the spare pack you bought? There are only three lipo manufacturers in the world, so the chances are good that you can find a "good" battery online that is as good or better than the OEM. I've had great results from the Zippy "Rhino" series of batteries. Regular Zippy's are ok too, but the "Rhino's seem to perform a little better. Turnigy is good too, but the Turnigy packs also seem to have a little less burst power compared to a Rhino of identical size, capacity, and "C" rating.

Keep having fun!