Hi All,

I've not yet found anything that can help but any suggestions greatly appreciated. I'm building an embedded device powered by battery. It's possible/likely that over time the battery will go totally flat. It'll be on charge all the time it's being actively used, and in hibernate mode at other times. The challenge is that if the battery goes totally dead, plugging in the charger (and hence giving the Teensy the volts it needs) does not reset/boot up the Teensy. It's just not responsive.

Any suggestions as to why this might be? Or what I might need to do? I can reset the Teensy by shorting the reset pin to ground - this was one of my many reasons to build a custom Teensy as the reset pin is difficult to use on the pre-built models. I can also reset it by cycling the power, but this isn't an acceptable solution in my embedded device.

I'm using a Li-Ion battery (18650) and a small on-board switching battery charger. If it helps, I also have added the ability to monitor the battery voltage all the time the system is running, so I could respond to a low battery event in some way or other before it gets critical.