We were having a communications problem and decided to hookup 6 electrons to the same USB hub and power supply. Although all appeared to be charging, when someone went it 2 days later, 3 of them had dropped off the line.
All showed the blue led bug when first inspected. For 2 of them, once they were connected to a better power supply and the devices reset.
However 1 of them has not reset properly. I tried a different battery with no luck.
This one had no board connected at all. The only connections was the USB, battery and Antenna.
We are using the 7.0.0-rc6 firmware. We have ~12 particles in the field (With the same firmware) and all have had the battery run down on all of them (Multiple times). None have exhibited this behaviour before. NB. These all charge off the Vin port where as this one was via the USB. They also have a screen attached that runs off the 3V3 rail.