Specs and features of the charging circuit on the ESP32 DevKit LiPo

[BenIndustries]

Hi everyone - hope you're project are going well!

We're using the ESP32-DevKit-Lipo Rev. D - Olimex part# 93658. Can anyone provide information on the charging circuit of this board? We're using 18650 LiPo batteries (usually 3200 mAh versions) to power our device and we're keen to know how well featured the charging circuit is. Does it provide any bms functionality (overcharge, low voltage protection) or other protection or should we specify protected 18650 batteries with their on bms or fuse protection as well?

Thanks in advance for any insight.

RK

[LubOlimex]

The charger is BL4054B-42TPRN, the datasheet here:

https://www.belling.com.cn/media/file_object/bel_product_en/BL4054B/datasheet/BL4054B_V1.5_en.pdf

If you are interested in battery operation maybe you are also interested in power source sensing and battery charge measuring, in that case consider these are disabled by default (to have more GPIOs). But you can solder together the three SMT jumpers to enable that functionality, refer to the schematic of the board. Jumpers are BAT_PWR_E1, BAT_SENS_E1, GPI39\SENSOR_V. Schematic is here:

https://github.com/OLIMEX/ESP32-DevKit-LiPo/blob/master/HARDWARE/ESP32-DevKit-LiPo-Rev.B/ESP32-DevKit-Lipo_Rev_B.pdf

[BenIndustries]

Super helpful - thanks. Yes, we have closed all those jumpers and are using those features.

Thanks so much.

RK

[LubOlimex]

You can use this Arduino demo as basis if you have troubles with the power reading:

https://github.com/OLIMEX/ESP32-POE/blob/master/SOFTWARE/ARDUINO/ESP32_PoE_PowerReading/ESP32_PoE_PowerReading.ino

It will work fine without the need of any changes for ESP32-DevKit-Lipo (since the pins used for external power sense and battery measurement are the same - GPI39 and GPI35). Just make sure to load the proper Olimex board from the menu (ESP32-DevKit-LiPo).