I wish DJI would consider this. There is no reason they couldnt put a smaller reserve battery inside the Phantom that would only kick in when its emergency. It wouldnt have to hold much or weigh that much. Just something that will get you an extra 5 minutes or so in case your main battery fails. Battery failure is becoming fairly common recently and this would be another good feature as a fail safe. It would only kick on automatically only if your regular battery is dead and not meant to be a way to squeeze a few extra minutes of flight time.