Building and flying multi-engine models can be heaps of fun. There are loads of foamy models to choose from and when flown brushless it all comes together. Many of these foam models are in a size where using the BEC makes perfect sense.

But how do you connect two BEC controllers when they are each feeding a supply of power to the receiver?

The answer is that you don’t. It is ‘best practice’ to disable 1 of the BEC circuits, and this is simply done by cutting the positive wire to one of the controllers. If you do it on a short servo extension cable you can keep the controller intact for its next deployment.

If you do decide to just connect both BEC feeds to the receiver it might work, but you may also experience that one of the BEC’s lets out the holy smoke. The BEC circuits won’t have exactly the same voltage, so one of them will take all of the load, or drive the other crazy… I have not investigated the technical explanation but we have seen it in real life.

So - one BEC needs to be disabled. Cut the red wire on either of them on an extension cord and you are ready to continue with your radio installation.