Powering Two ESP32 from VESC 4.12 BEC

Esk8 Electronics DIY Solutions
1

Hi everyone,

I’m currently working with a Flipsky VESC 4.12, and I’d like to ask for advice regarding the BEC 5V power capability.

My setup is as follows:

  • I want to connect two ESP32 boards to a single VESC

  • Both ESP32s are powered directly from the VESC 5V BEC

  • ESP32 Wemos D1 used for real-time control via UART

  • ESP32-C3 used for data logging via CAN, running VESC Express

  • WiFi is enabled on both ESP32s simultaneously

So effectively, the VESC BEC is supplying:

  • 2× ESP32

  • Both with active WiFi

My questions are:

  1. Is the 5V BEC on VESC 4.12 strong enough to reliably power two ESP32s with WiFi enabled?

  2. Has anyone here run a similar dual-ESP setup long-term without issues?

  3. Could this cause BEC brownouts, VESC resets, or watchdog faults under load?

  4. Would you recommend:

    • adding an external buck converter, or

    • powering only one ESP32 from the VESC and the other externally?

Any insights, measurements, or real-world experiences would be greatly appreciated.
Thanks in advance!

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2

That should be pretty easy to figure out. It might depend on your VESC, because often the 5v supply is very weak and just for logic level stuff, and the 12v is used for higher power stuff like lights and horn.

But I found a rating of 1.5a for the 5v on a 4.20 plus dual and the ai answer for esp32 current draw said they use very low current normally, and a max of 0.5A when doing Wi-Fi related things.
But honestly a 5V bec is really cheap, might give your vesc one less reason to die and if you’re powering anything else is worth it. I got a 5V 20A one for lights.

What are you using the esp32 to do? Will they communicate with the vesc?

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Both ESP32s are used only for communication with the VESC, there are no additional external I/O devices connected to them.

  • The ESP32 Wemos D1 communicates with the VESC via UART for control commands and basic telemetry.

  • The ESP32-C3 communicates with the VESC via CAN for logging and monitoring (VESC Express).

Aside from that, they are not driving relays, sensors, displays, or any other peripherals. The only significant load on both boards is the ESP32 itself with Wi-Fi enabled. That’s why I’m mainly concerned about Wi-Fi current spikes and 5V rail stability, rather than continuous current draw.

Thanks for the insight!

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I am desperate for a nice way to get speed or rpm or duty cycle info from a vesc for controlling a stepper motor or servo to compress bushings at speed. Would it be easy for you to tell me how you do it?