The absolute max ratings (in this case 17V - even very short spikes) and the recommended range (in this case 3.9V to 12V continous) are typically not falling together.
And there have been others asking in a similar directionhttps://community.particle.io/search?q=17v
With a quick search for above term 17v and a brief browse over the results you might have stumbled over this very post
That’s an interesting behaviour.
You are correct, the PMIC is rated at 17V max. We have tested the Electron to operate at 17V as well. Due to the size constraints of the PCB, there isn’t enough thermal dissipation available. This is the reason we have capped the max input voltage to 12V so that the operation is guaranteed to run cooler. You can definitely run it above that voltage but you may run into overheating. Having said that, the PMIC has an inbuilt thermal shut-off, so it won’t destroy t…