Bleebs

Got a question about using a 4.8v receiver battery pack on an electric plane, when the ESC already has a BEC.

I know that everyone says you should remove the pin attached to the red wire in the receiver plug of the ESC, but what if you don't?

Surely the power supplies would work in parallel, and act as backups to each other?

Or would you just cook your receiver?

Anyone tried?

Walt Thyng

My Feedback: (9)

I'm not an E.E., but I've been flying electrics for 17 years. My experience is that when you fail to disable the BEC while using a RX pack you let out all the magic smoke on the BEC side of the ESC. Something to do with the Moffets and voltage regulator circuit.

Short answer: don't do it.
Walt

whitecrest

I believe it is difficult to match the battery and BEC voltages precisely potentially allowing large currents to flow in the wrong places and possibly resulting in component damage. You definitely don't want to lose your receiver voltage. If you need a lot of power to run your receiver and servos, I would recommend using a switching UBEC.

-pkh-

My Feedback: (2)

If you connect a battery up to a voltage regulator (BEC) output, you have no idea what the current draw will be. The battery may sink more current than your BEC can provide, in which case the BEC will either go into thermal shutdown (if it has such a feature) or it will "smoke".

Bleebs

Ahhh!

You see, that's the value of asking questions on forums before you stupidly go ahead with some hair-brained scheme.

Never crossed my mind that the Rx battery pack would accept a charge from the BEC, and fry it to a crispy shade of black in the process. I just assumed that they'd work together in parallel. Not very smart.

Thanks for the advice guys. You've just saved me from cooking a very expensive 95A speedie.

Cheers.