Hi, thanks for you fast reply. Sounds like I need to play a little bit around with deep sleep to avoid fast battery drain.

I've created a piece of code receiving some sensors states with mqtt and publish m5paper temperature and battery voltage via mqtt to home assistant. To keep the m5 awake I run a simple loop:

hile True:
wait(30)
m5mqtt.publish(str('temp_nebeneingang'),str((sht30.temperature)))
m5mqtt.publish(str('battery_m5paper'),str((bat.voltage())))

So far so good, but in case I run this on battery after about 2h the m5 stops working showing the last display. During this timeframe battery voltage reported went down from 4900 to 3200 within 2,5 hours.
What I'm unsure about: Is the m5 going to deepsleep and not responding anymore or is the battery really empty after this short timeframe?
Even pressing the reset button doesn't evoke anything, only connecting usb power again.