I'm using an STM32F0 in a high volume low power project running on a LIR2032 that can be charged via USB. The STM is specd at 2.4 - 3.6V, with 4.0V as the absolute maximum. When the battery is fully charged however the voltage will be 4.2V, 0.6V out of spec.
Now, if I power the device with 6.5V for a few days it actually still runs fine, except for a drawing scary high currents (81uA in standby compared to 3.12uA on 3.3V). What exactly happens when you apply a too high voltage to a device like this, and what are the actual risks?
Thanks in advance!