Battery voltage, percentage and charging status for ESP32-C6

[ZJouba]

Good day all,

I'm very much a noob with micro-controllers and IoT and I need your help please. I have the FireBeetle 2 ESP32-C6 board and I'm trying to get the battery voltage, percentage and if it's currently charging or not.

I have a 3.7V 5000 mAh LiPo battery hooked up.

Please help me with the code and explanation to get the battery voltage, percentage and charging status?

I decided to open a new discussion because I couldn't find other questions where the charger and PMU are integrated into the board like with the Firebeetle 2

[robert-hh]

According to the schematics of the board the only information about the battery state you can get to the ESP32 is the battery voltage. That does not tell you much about the battery state. Li-Ion batteries have a voltage about 4.2V when full. When discharging, it drops fast to about 3.7V until almost empty, then the voltage drops fast until the protection circuit in the battery (if present) cuts it off at 2.6 V. So what you can tell: If the battery voltage is about 4.2V it is full, if it is below 3.2V it is empty.
The charging chip has a charging LED, but the output is not connected to the ESP32. So coded cannot tell whether charging takes place or not. A battery manager which tells about the charge measures the in/out current and voltage of the battery. But that is not present on the board

[robert-hh]

s the CN3165 the PMU of this board?

The CN3165 is responsible for charging the battery. There is an additional switch which selects between Vin and Solar Panel as input for the CN3165. Power regulation is done by the TPS62A02, which takes it's input from either the battery, Vin or the solar panel.
You can use the /DONE pin to indicate that the charging is complete. It is an open drain active low output, so you will need a pull-up to get a high level. Wiring it up to the ESP32 could be a challenge.

[davefes]

One bi-directional current monitor should measure the current going into the battery and the current coming out of the battery.

[ZJouba]

@robert-hh - Thanks for the info, where do you see the TPS62A02 on the schematic?

[robert-hh]

I see, there are two variants of the board schematics. V1.0 uses a HM6245 as regulator, V1.1 uses TPS62A02. The TPS seems better, since the input range is down to 2.5V, whereas the HM6245 would need at least 3.4V to return a 3.3V output. The other side of the coin is input voltage. TPS62A02 max 5.5V vs. 8.5V of the HM6245. The solar panel output may go beyond 5.5V unless limited by an additional circuit.

[ZJouba]

Ah! I have the V1.0. Thanks for all the help and info!

[ZJouba]

For future reference - it's not possible without either additional hardware or physical changes to the board