I agree with what has been advised above
However, if your using over 4 digital servos in your setup you need to rethink things.
Digital servos drain more power out of your battery so the playtime is less if your using say 6 servos vs 4.
I almost lost a Venus II about six weeks ago because I didn't have a large enough battery in the airplane. The problem occurred on the third flight with the Voltwatch indicating ......... ALL IS WELL!!!!!
I have now switched my thinking to using a 6 volt battery for everything beyond 4 servos, and then keep close track of the voltage after a couple of flights.