Help! external BEC for Aura 5 Lite?

[Monte.C]

It's a pretty basic question.
Isn't it true that on a common ESC/Rx setup the ESC (with built-in BEC) supplies the power to the Rx? And through the same lines/connection the Rx controls the ESC, right? One line that's just like a servo line.
I'm trying to build real small, and I have a really small ESC with a separate tiny BEC. Now with my Aura I don't seem to have enough ports!
Can I use a separate BEC with the Aura? Or do I have to use a giant, heavy 20A ESC? Ugh!

 

[LitterBug]

You could "Y" the BEC power in to your ESC port.

 

[Monte.C]

How about: what's the smallest lightest ESC with BEC I can find for maybe 12A? I suppose I need like 3A BEC output (?)

You quad guys, is there a quad ESC that would work for me? They seem inexpensive for a 4-pack.

(I call the drone guys "quad guys" when I need something. )

 

[Monte.C]

You could "Y" the BEC power in to your ESC port.

Oh SERIOUSLY? I was just wondering that - hoping beyond hope.
Like... Splice in the BEC power to the ESC line?

 

[LitterBug]

Quad ESCs don't usually come with BECs.

 

[LitterBug]

Oh SERIOUSLY? I was just wondering that - hoping beyond hope.
Like... Splice in the BEC power to the ESC line?

yuppers. As long as you have a common ground, you could just pop the red wire in the middle position.

 

[LitterBug]

A 12A ESC probably has a small BEC.
IE 12A ESC with 1A BEC https://www.buddyrc.com/collections/plane-esc/products/ztw-mantis-12a-esc?variant=30274466381910

 

[Monte.C]

Aw killer. Way killer. Dude you know your stuff. I thought these all carried 3-lines but I just checked. The ESC and the BEC both have only two lines - for obvious reasons. I'm back up & running again.
When you say common ground... Would I need to splice in the ground to ground to join them? Oh no wait, they're sharing ground with the battery, so that's ok right?

 

[Monte.C]

So it sounds like I just run the red line into the ESC Rx connector, and forget about the ground/black line on the BEC. Does that sound right?

 

[LitterBug]

Or a 12A ESC with 2A BEC https://www.getfpv.com/v-good-rc-32-bit-12a-2-4s-brushless-esc-for-rc-airplane.html

 

[Monte.C]

A 12A ESC probably has a small BEC.
IE 12A ESC with 1A BEC https://www.buddyrc.com/collections/plane-esc/products/ztw-mantis-12a-esc?variant=30274466381910

I found ones like that but I thought 1A wasn't enough. I thought I needed like 3A.

 

[LitterBug]

If you are powering the BEC and ESC from the same battery, the connection to the battery is the only negative lead you will need. You would not need to have another going to the FC

 

[Monte.C]

Or a 12A ESC with 2A BEC https://www.getfpv.com/v-good-rc-32-bit-12a-2-4s-brushless-esc-for-rc-airplane.html

That one looks less micro.
Can I safely join the wires? You said just the red? Forget about one of the grounds? Which one?

 

[LitterBug]

The + (red) output of the BEC needs to be in the middle of the 3 wire ESC connector. The - (black) is common via the power input to the BEC and ESC battery terminals.

 

[LitterBug]

How many servos are you feeding?

 

[Monte.C]

The + (red) output of the BEC needs to be in the middle of the 3 wire ESC connector. The - (black) is common via the power input to the BEC and ESC battery terminals.

Ok sounds like the ground doesn't care about "in" or "out" as long as each component is grounded to the battery.

 

[LitterBug]

Ok sounds like the ground doesn't care about "in" or "out" as long as each component is grounded to the battery.

Correct.

 

[Monte.C]

How many servos are you feeding?

4 really small Emax servos, smaller than the common FT/Emax 5g mini servos.

 

[LitterBug]

probably 2.5g servos. since you are running everything off a single BEC, it would be wise to go 3A or more.

 

[Monte.C]

probably 2.5g servos. since you are running everything off a single BEC, it would be wise to go 3A or more.

I have 5V 3A.