I also had issues with depleted battery on Braveheart. I am now charging it in the factory test. It draws around 1.3A at the moment (started way lower) so I assume that it's charing the battery.
However, I am also getting the external battery charger to be able to charge the battery independent of the OS.
I also have a dead battery and wonder how can troubleshoot this. I can plug the usb-c to a windows machine and it registers that something has connected but that's all. I've tried measuring the voltage at the phone battery pins without success. Makes me wonder if the pins have to be pressed in, e.g. battery in place, to see. Is there anywhere I can check voltage from the usb-c? I see 6 pins up near the serial jack. I had tried earphones in the serial jack. I'm wondering if the usb-c cord is bad and have no other usb-c cord or device. Thanks.
soy