Even at that, you would have to have a HUGE battery bank to be able to play for 1+hrs. Then if an amp is rated at 300 watts rms, 99% that rated at 14.4 volts. His setup would float around 12-12.5volts. So a 300 watt amp now becomes a 250 watt amp. So the whole setup might draw close to 30-40 amps. (They amp alone would draw 21amps if its 100% efficient, which its not) So Yes on batteries it could be done, you would have more money in batteries than just buying a pro sound amp.