Samtheboxer,

Dave has already sent you a link that explains what a voltage divider is and how to figure the correct values of resistors to use so I won't repeat his info.

Whether you use an ADC or comparator you will need to use a voltage divider to divide down the battery voltage into a range that is safe for the PIC.

I suggested using a comparator and interupt because it doesn't require clock cycles from the PIC unless the battery voltage has dropped below the pre set threshold. I was thinking that he just wanted some sort of failsafe that would shut things down if the battery voltage dropped to low but do other things in the mean time. I am using just such a feature on a project that I am working on now. After re reading the original post I see that what was really wanted was to circuit that just monitored the battery voltage and for that the ADC approach is better.

Which circuit and code you use depends upon what it is you are wishing to accomplish.

Terry