Customer:
I purchased a Li-ion battery 10000mAh 3.7V to use with my Inkplate 6. I connected it successfully, but the device is not working on battery power: when I switch from USB power to battery, the device enters a boot loop with the screen flickering dark and white approximately every 1 second. I cannot run even the simplest Inkplate6_Read_Battery_Voltage example from the Arduino library. I left the device plugged in overnight to fully charge the battery, but the problem persists. Is the battery defective?
Originally submitted via email support on 24 July 2025. Migrated to the forum for community visibility.
Soldered Support:
To help diagnose this, please measure the battery voltage with a voltmeter or multimeter and share the reading.
Customer:
The battery voltage measured with an analogue multimeter is approximately 4.15V, which seems normal to me.
Soldered Support:
The ESP32 appears to be continuously resetting. To understand what’s happening, you need to see the error message from the UART output. Try reading the UART output directly from the RX and TX pins. Since the reset does not occur when connected via USB, monitoring the UART output will provide more insight.
If the message indicates a brownout error, the battery is likely the issue. However, if it shows a POWERON_RESET, the problem may be related to the pull-up resistance on the MANUAL_RST pin of the low-power reset IC (TPS3840PL27DBVR). In that case, adding a 10kΩ pull-up resistor should resolve the problem.