If you have a FC with a 5V 0.8A BEC and you are using a VTX that pulls 0.65A. Would you need to power the camera directly from
the Lipo?

So the longer version.

I have bought a 1S F3 AIO for a whoop build.  SPI D8 built in, so no need for a receiver.  But the 5V BEC is pretty small in output at 0.8A.  VTX will be an ovx300, camera probably a caddx ant nano.  Spec sheet for the ovx says it uses up to 0.65A (650mA @ 300mW, but presumably less at 100mW).  The camera I can't find anything on power usage, but guessing around 0.1A (BetaFPV C03 uses 100mA).

If run at 300mW with a nano camera, would it be safe to run it all from the BEC or would it be a better idea to power the camera and/or vtx directly from the Lipo?

Specs for Racerstar Crazybee F3 Wrote:Specifications:
Firmware: Betaflight_3.3.0_Crazybee
MCU: STM32F303CCT6 (72MHZ, 256K FLASH)
Sensor: MPU-6000(SPI connection)
Power supply: 1S battery input (DC 3.5-4.35V)
Built-in 5A(each) Blheli_S 4in1 ESC Dshot600 ready
Built-in Frsky receiver with telemetry D8
Built-in Betaflight OSD(SPI Controll)
Built-in Current meter (Max 14A,could be modified to 28A by replace resistor)
Built-in 5V 0.8A BEC with LC filter
Built-in voltage detection
BLHELI_S pass-through Ready
Heading LED Ready
Board size: 29 * 29MM
Board weight: 3.5 g

ESC parameters:
Power supply: 1S LiPo/LiPo HV (4.2v/4.35v)
Current: 5A continuous peak 6A (3 seconds)
Support BLHeliSuite programmable
Factory firmware: O_L_5_REV16_6.HEX
Signal Support: Dshot150/Dshot300/Dshot600/Oneshot125/Multishot/PWM

Receiver parameters:
SPI BUS receiver
Compatible Frsky D8
Channels: 8ch
Failsafe support
No ground interference ( Transmitting and receiving 1 m from the ground): 300m

I didn’t know there were boards out there with that low of a current rating on 5v.

You’re gonna be awfully close to the rated limit if you wire both the ant and the ovx300 to the 5v bec, but you may not have a choice- I’d just keep the vtx power lower.

If I recall correctly, (don’t quote me, double check), the Caddx ant nano can take 5v to 25v. The ovx300 needs 5v.

A 1s lipo is gonna put out significantly less than 5v, so if you wanted to wire direct to battery you would need a step up voltage regulator to bring your 1s voltage up to 5v.

It’d add extra weight (2g), but, something like the Matek VB2A5 voltage booster would work well. It can handle 2A.
http://www.mateksys.com/?portfolio=vb2a5v

Another option would be to use a different camera that can run off 1s voltage.

Edit- Caddx’s website says the ant nano can handle 5v to 25v, but retailers say it can handle 3.7v to 18v….

I've got one of those Crazybee F3 AIO FC's in my Eachine UK65 whoop. They were really designed for low power AIO cameras which have a VTX attached to the back of them. The one on the UK65 only draws 300mA which is for the camera and 25mW VTX combined (see HERE).

Unless you add an additional external BEC you are going to have to do what Lemony said about using less VTX power. I wouldn't connect any external peripherals direct to LiPo voltage that is only 1S because any voltage sag during flight will risk a brown-out on those peripherals.

Not related to your question, but you can run Bluejay on the ESC of that Crazybee F3 AIO FC with no issues. I'm running it on mine. Official Betaflight support for F3 processors ended with Betaflight 4.0.6 but you can get it onto a slighlty newer version if you flash Joe Lucid's Betaflight 4.1.1 EA3 Performance Edition firmware (see HERE). I also run that on mine and it works just fine.

Thanks for that link Snow. i knew I could get 4.0.6 on, but 4.1.1 is maybe a bit nicer, but I do notice acro trainer is removed, which i was going to try and force on to my nephew for outside flying. But at the same time if I set him up with Angle and Acro, it's probably just as good.

I think vtx/cam wise, Unmanned do one based on the AKK AIO-SA, it does up to 200mw and uses just under 0.5A, so would definitely work using the onboard BEC. Link is below. I think that is probably the one I will use.

https://www.unmannedtechshop.co.uk/produ...200mw-vtx/

For this build I will be abandoning everything except the motors. I'll be putting the Moblite6 motors on to a Meteor65 or 75 frame, with a Betafpv whoop canopy or if the AIO cam won't fit, one of the newer PE canopies and the F3 board. It will be really basic, but it's something to cut his teeth on.