We are making a simple bot that uses a 12 V lithium ion battery,which is connected to a power module, for 5V and 3.3 V output. Now I connect a TB6612FNG motor driver with ESP32. The ESP32 is powered by 5V from the power module mentioned above, while the motor driver gets 12 V from the power module. I have used two BO Motors with motor driver. I have also connected a motor servo with the battery. It is driven by the PWM output from the ESP32.

While this setup may seem simple, we are facing various problems like the motor driver and power module getting burnt up. Sometimes ESP32 is burnt up.

The problem is with the battery. Is there any solution to this problem? Will using a LM2576 solve this problem or is there any other method?

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    \$\begingroup\$ Limiting the current to 1A from a 12V battery won't do anything to save your ESP32. Something else is going on. We need to see your schematics. \$\endgroup\$ Commented Sep 17, 2021 at 19:19
  • \$\begingroup\$ I have added the schematics to the original question. Btw ams1117 on the power regulator module as well as motor driver also got burnt up. That's why I reached on the conclusion that they are drawing too much current, am I wrong somewhere? \$\endgroup\$ Commented Sep 17, 2021 at 19:39
  • \$\begingroup\$ Connecting 5V to the ESP32 doesn't sound like a good idea, and you don't seem to have it connected to ground. Are you sure that schematic is correct? \$\endgroup\$
    – Finbarr
    Commented Sep 17, 2021 at 20:55
  • \$\begingroup\$ XY problem. Please show exactly how you connected everything. I sense a ground and/or layout problem. \$\endgroup\$
    – winny
    Commented Sep 17, 2021 at 21:04
  • \$\begingroup\$ the power module is the problem, not the battery. Those tiny SMTs can't turn 12v into 3.3v at the current an ESP32 needs; even my to-220s that i use for that need several cm of heatsink and they still get uncomfortably warm. Use a buck converter to get 5v, then you can use a tiny 3.3v LDO. \$\endgroup\$
    – dandavis
    Commented Sep 17, 2021 at 21:08

1 Answer 1


Your power module is almost certainly a problem if it's an AMS1117 which is a linear regulator.

A linear regulator drops the voltage and burns the same current as the device it is powering.

That servo pulls about 200mA at 5V but can pull up to 400mA when near stall. The ESP32 is about 200mA in WiFi. That means that the poor power module is dissipating up to 600mA*(12V-5V) which is about 4.2W(!) of power.

You need to get a DC-DC switching regulator (likely Buck topology, but as long as it is a switching regulator, you're fine).

One thing to note, though. Motors tend to be inductive loads. That throws off a lot of the calculations for power supplies which tend to assume that the load is resistive. You may need a bigger regulator than you expect.

Good luck.

  • \$\begingroup\$ Thanks a lot, this helped me to solve the problem. \$\endgroup\$ Commented Sep 21, 2021 at 11:23

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