I bought one of the DFRobot “Solar Power Manager” boards to use with Li-Po battery and solar panel to power an ESP32 running ESPHome at remote location (OK, its only my greenhouse in the back yard, but no mains power there).
I discovered that when the battery runs down, the battery’s under-voltage protection shuts off power and the ESP32 just dies without warning. Is it too much to ask that the microcontroller is given an opportunity to send a low battery notification, and shut down cleanly ?
To get any info about the battery and solar panel voltages we have to add more circuitry which at least doubles the cost and complexity. I do understand that each “feature” adds complexity and cost - but surely cheaper to build them into the “power manager” board than tack them on piecemeal afterwards ?
But the real kicker was following the ESPHome INA3221’s documentation to SwitchDoc.com’s page and discovering that SwitchDoc Labs were selling power managers with all these features back in 2016 ! But Covid and part availability led them to discontinue their maker-oriented business.
Looking in HA and Adafruit forums this is a fairly common issue, so surely there are other LiPo & Solar charger boards that provide a low battery warning to an attached microcontroller ? Probably better to use an INA3221 to allow the microcontroller to monitor battery and solar power via i2c … and maybe a KA75330 or similar to awaken the microcontroller only after the battery has recharged sufficiently.