I’m building my first project on ESP32. I figured out many things regarding programming and wiring.

Now I want to power if from battery and be able to charge this battery using Qi wireless charger.

Here is the parts I use:

1. ESP-WROVER-KIT V4.1 – ESP32 board with integrated LCD screen. Requires 5V for external power
2. MT3608 – DC-DC Step Up Power converter – I use to convert 18650 current to 5V
3. TP4056 – charging module that works with type-c charger or any other 5V external charger
4. 3W 5V Qi wireless charger – I’m not exactly sure what controller it uses but it seems to be CP2022
5. 100kΩ voltage divider to measure current battery charge connected to IO34 of ESP32.
6. Two 18650 batteries connected in parallel.

Here is my schematic: https://www.flux.ai/korvin-1/esp32-5v-power-and-charge. I also attached few photos below.

Now, there are few things that work:

• My ESP board works when powered from this module. I don’t see any issues.
• Divider on pin34 seems to show battery voltage. The value is not precise (3.9V when my batteries are at 3.57V). Maybe I need to tweak my formula, or maybe this is because I connect the divider after charger module.
• Charging seem to work from USB. The red LED is glowing on TP4056 and I think the voltage displayed on the screen slowly increases.

The main problem now is that wireless charging doesn’t work well. When I put the coil on the charger it is detected correctly and starts charing (red LED on my Samsung charger and on the TP4056 module both glow). But then after a minute or so, connection seems to be lost. It may reconnect couple of times, again for a minute or so. But usually it won’t reconnect and I need to remove the coil and place it again to make it work.

So here are the questions:

1. Does this setup make sense in general?
2. Is it OK to put voltage divider between charging module and DC-DC converter or should I put it between B+ and B- of TP4056?
3. I saw few threads online saying that I shouldn’t charge the batteries while keeping my load connected. Is it a known problem of TP4056? I doesn’t make sense for me. Is there a way to resolve this issue or should I switch to another charging module?
4. What could be the problem with wireless charging? I tried few different Samsung emitters and all of them cannot maintain the link with the coil more than a few minutes. Can you recommend some alternative Qi receiver module that works better?
5. Are there any good threads here on reddit or anywhere else where I can seek for help with this?

Thanks in advance for your help!

full setup