If you meant 'I want to monitor the Battery voltage' it will never work @4.6V

If you meant 'i want to monitor the PIC 5Volts rail' you MUST have a accurate and stable ref point somewhere. Zener will work but need too much current, voltage reference are great.

But there's certainely something i miss here. Usually i'll monitor the PSU before the regulator with high value resistor R2R network. The internal comparator allow that.

Something to try i guess Mr tomskk?