Voltage monitor for car battery

[mackrackit]

The OP hasn't specified a device. If using the popular 16F88, the maximum recommended analog source impedance is only 2.5k. It is always best to stay within the specifications of the device for reliable results.

Regards,

Andy

Are you sure you have the correct data sheet. Section 12.1, paragraph one in the data sheet titled PIC16F87/88 clearly states "The maximum recommended impedance for analog sources is 10K."

I do agree one needs to stay within the specifications if you do not want to see the magic smoke