Originally posted by martinjpainter
The idea is to stop putting the current through the receiver for the high drain servos. The digital servos use a lot more current than standard servos. A lot of the receivers were designed before digital servos were readily available and may struggle when the extra loads are being placed on them.
I am just being extra cautious. I have not experienced any problems but I am trying to pre-empt them.
The only other time I have used two battery packs is on my Kyosho Corsair ( http://www.mjp.co.uk/model%20aircraf...air/index.html ) where I have a separate pack for the retract servo. This is incase the retracts foul when in the up position and cause the retract servo to stall and drain the receiver pack in flight. This way I would only loose the use of the retracts opposed to control of the model.
If that is the only reason, you shouldn't worry. Its common to see 40% airplane with 9 digital servos, and a couple analog servos, all running through one or two receivers. A few people have tested the receivers buy running 10amps sustained, and 20amps intermittent, and neither receiver had a failure.
My thoughts, for what they are worth, would be that you would add more unnecessary complexity, and more failure points, to offset a failure that has yet been unsubstantiated. To my knowledge, I have never seen a receiver failure discussed on all the forums I have been following (IMAC, IMAA, GSAL, RCU, Newsgroups) that was caused by excessive current. I have also seen single receiver planes fly with dual 2700mah packs, and 8 or 9 digital servos for season after season without any issues. If those planes can handle 9 servos without failure, you should feel fairly comfortable with running only 4 digitals.
The situation with the retracts is a good use of the technology and methods. I could easily see a failure of that sort taking the pack down. I had something similar in my 40% Giles, with a rudder servo that failed, stuck hard at neutral, and the other servos (ganged servos on the rudder) were fighting against it to try to move it. It drained one of my fully charged packs during one 10 minute flight. I almost lost the airplane. Luckily, I was running dual receivers, and the other receiver/battery pack was untouched. I was fortunate.
Regards,