I've got a strange problem occurring with FiPy/Pysense when running on battery. The device publishes every hour to MQTT broker from a FiPy (over LTE) mounted on Pysense. My code is running fine and the battery slowly goes down from 4.1v, but suddenly FiPy stops publishes after a while; the problem can occure from 2 days to a couple of weeks. See example with attached picture: I unplug the USB from Pysense and it runs on battery from december the 2nd; everything seems ok during 1 week and then stops the 9th...
When I measure on the back side of Pysense, the voltmeter returns 0v?
When I load the battery for a couple of minutes, the charge is already around 3,8V. It looks like a short-circuit. I've changed the battery with a new one, but still have the same problem.
I have plugged the Pysense a couple of days to see from REPL if the code stops or stuck in infinite loop (which I doubt causes the problem because the code is secured with timeouts), but I don't detect any bugs. I would like to check the code running when device is on battery. This can be done with Putty through WiFi but I don't know how to avoid the terminal to go in timeout when FiPy goes to deepsleep...
I'm a bit confused and don't know how to go further with debugging. Any idea would be much appreciated :)