I'm going to assume that we're talking 2.4 rigs installed in 20-30cc planes (possibly smaller, maybe a little bigger, some 50cc guys are running it)? Whatever, someplace we might want to use a light weight, single battery system, including those with digital high torque servos, though that's not necessarily the case.

On single battery set ups, I think most guys are using 2 sets of wires coming from a single battery (at least 2, regardless of battery chemistry). Those 2 leads feed 2 switches (hopefully HD switches with fairly heavy wire). One of those 2 switches feed the receiver as you would normally. How the second is set up depends on the individual.

With SpinnerRow's setup (above), the second switch feeds the power "in" line on his opti switch. Nice and simple.

Others (like me) might take that second switch lead and run it to a "Y" inserted in the rudder channel. Don't want to confuse the issue about why you might want to go this way yet. Get to that later. To run this method, you need to get past the potential for problems caused by the opti switch back feeding the receiver with something that might cause problems. Not going to say that potential isn't there. I'll let the tech geeks argue that point. I WILL say, a BUNCH of us are flying this way with no issues, and have been for a 2-3 seasons. This is my second season this way without a single issue.

If your second switch is feeding the "Y" in the rudder servo, you still need to get power to the "input" side of the opti switch (or IBEC). That can be done with another "Y" inserted anywhere in the system that's handy. The red and black wires are the same (red positive/black negative) no matter where you see them in the system. The Rcexl switch comes with a diagram that has you placing 2 drops of solder to get it's "input" power from the line that plugs into the receiver, controlling the switch's on/off function. This lets you ignore the switch's "input" wire. It's not used.

Why would you want to run that second switch lead to a "Y" in the rudder lead?

1. Switch redundancy. No more concern about a failed switch. That only happens to you one time prior to looking for ways to avoid that happening again. This way either switch is capable of supplying the system.

2. Amperage available to the servos. That battery is capable of producing a lot more amperage than the wires you see commonly used can carry. The extra set of wires feeding the power circuit can provide a big boost in high demand situations - which is exactly why we use the rudder to install the "y". It's generally the biggest servo, and even when not, it's the servo pulling the most power most often - and this way it's getting a direct shot from the battery - in addition to what it might have ordinarily.

Hope this helps somebody trying to get their head wrapped around this. If I've managed to confuse, holler! -Al