HI Jetfan
For what it is worth I use only A123's but with a Regulator I have had 2 Servo's fried by using them straight into the receiver.I was lucky one was on my brakes and the other was on the retracts and before any one can say that they were probably stalling I can assure you that they weren't. I had a thread on this very problem late last year. I run 5.8 volts now and have not had a problem in any of my jets since. The only common between them was that they were both on short leads not sure if this was the reason but I wasn't going to take any more chances.
Cheers
Mav