@kubark42 could you try this app and let me know what you find? I’m getting good results after disabling charging.
If you don’t get good results, I’d like to see what your logs look like. Start particle serial monitor --follow
and then plug in your device after that. You can send them to my email if you don’t want to post here:
#include "Particle.h"
SYSTEM_MODE(SEMI_AUTOMATIC);
SerialLogHandler logHandler(115200, LOG_LEVEL_ALL);
void setup()
{
PMIC().disableCharging();
Particle.keepAlive(30); // would recommend 30 seconds with any 3rd party SIM as a default
Particle.connect();
}