I'm not real experienced with RC. Butt I can tell you this. If you have digital servos, they will suck some juice. I've also read several posts and talked to guys at the fly field. For my raptor 3 V1 they recommended in the neighbourhood of 2100 mah. The 600 mah that was installed they quickly frowned on. I already had 1800 mah for my radio so I didn't go any higher. After 1 flight my radio takes about 15 minutes to recharge using a quick field charger. The heli battery takes about 30 because of the digital servos I recently installed.
Hope this helps

Dennis
Sachse, Tx