PIC XC8 Battery Manager

I need a compact firmware-and-hardware solution that lets a PIC microcontroller, programmed with the XC8 compiler, manage a battery-powered power supply built around a lead-acid pack.

Here is what I am after: the PIC should start up from the battery, regulate or switch the output rails as required, continuously read the pack voltage, temperature or any other basic health indicators, and trigger clear actions (for example, low-voltage cutoff or status signalling) before the battery reaches critical limits. A simple serial, I²C or even LED indicator scheme is fine for status feedback—as long as I can read the key parameters easily during bench tests.

Please base the code on MPLAB X + XC8 so I can compile and tweak it locally. If you prefer a specific mid-range PIC that is readily available, let me know; otherwise I am open, provided it has the needed ADC channels and enough I/O for a few buttons or LEDs.

Deliverables
• XC8 source code with inline comments
• Schematic (PDF or PNG) showing the PIC, the lead-acid interface and any protection or regulation stages
• Bill of materials with part numbers that are in stock at major distributors
• A brief README explaining build steps, calibration constants and how to extend the code for extra sensors

I will test by flashing the hex file onto a dev board wired exactly to your schematic, connecting a 12 V lead-acid battery and checking that the system powers up, reads voltage correctly and cuts off at the threshold you set in code. Feel free to suggest improvements such as temperature compensation or charging logic if you think they add value.