what battery is used with this?
1. Expensive way: Anton Bauer Lithium-Ion Battery.
3-10 Ah capacity depending on model (Watt Hours = Voltage * Amp Hours).
Pro: Really lightweight (1.7 lbs. / 770 g).
Contra: It's expensive ($250-$400).
Charger is even more expensive.
2. Cheap way: Lead-acid UPS batterie.
7-12 Ah capacity.
Get wire, Anton Bauer tap and connect it to battery.
Pro: It's cheap ($10-$20).
Contra: It's heavy (5 lbs / 2.3 kg).
3. DIY way: RC LiPo Batterie.
Battery voltage could be 7.4, 11.1 and 14.8 Volts.
For using 7,4V batteries you need to connect two of them consecutive.
11.1V could give a little underheating I think.
14.8V will work fine.
You'll need special LiPo battery balanse charger.
Pro: cheap ($30-$100), lightweight (1.3 lbs / 600 g).
Contra: LiPo battery should not be over discharged so you'll need to get extra Lipo Battery Voltage Tester that will make alarm sound on critical discharge or LiPo Cut-Off Module that will prevent over discharging.