Absolutely not! The 3V3 pin bypasses the onboard 3V3 LDO regulator, and if you connect a battery that can be as high as 4.2/4.3V, you could potentially damage components on the 3V3 rail that can’t handle higher voltages than 3V3, including the ESP32 chips.
Can I connect my battery to the 3V3 pin?
Updated on July 31, 2023