maybe someone could help me with this i have put in four futaba s9252 digital servos and one s3004 . someone said that the digital stuff eats your battery up fast . was trying to stay lite so i had a nr-4j 600mah and was going to use how long would this run and should i go bigger like a 1500mah thanks for any help and is there a fomula to figure out the how long a battery will run a said amount of servos?