I know what it says elsewhere in the datasheet for maximums, but I think it's not that simple for Vbat. Snippet from datasheet -
3.10.3 VBAT battery voltage monitoring
This embedded hardware feature allows the application to measure the VBAT battery voltage using the internal ADC channel ADC_IN18. As the VBAT voltage may be higher than VDDA, and thus outside the ADC input range, the VBAT pin is internally connected to a bridge divider by 2. As a consequence, the converted digital value is half the VBAT voltage.
I think it's not going to hurt the chip because of this -
the VBAT pin is internally connected to a bridge divider by 2. As a consequence, the converted digital value is half the VBAT voltage.
The Vbat does not "power" anything it just goes into a divider for monitoring. I think it's just measuring half the external Vbat and then multiplying it back to the actual value, so it can handle higher voltages (makes sense). In any case, I've had my diode (the SD103AWS part) in two units unit for several weeks and had the things on for hours at a time and it still works the same. I do not think it's a problem. :-)
