MPPT Solar Charge Controller — 300 W Class

Overview

A microcontroller-driven boost converter charging a 45-cell LiFePO4 pack directly from a solar array, delivered with a 33-page design report traceable to manufacturer datasheets.

Challenge

Design a 300W MPPT solar charge controller with 50V solar input charging a 45S LiFePO4 pack, with multi-rail auxiliary power, isolated current sensing, and full first-principles derivation of every passive value.

Our Approach

• Boost topology with paralleled MOSFETs and IR2110 gate drive
• Isolated Hall-effect sensing (ACS711/ACS712) with analogue front end
• Three auxiliary rails (12V, 3.3V main, 3.3V USB) with power-path isolation
• ESP32 control with MPPT algorithm and charge state machine
• All passive values derived from first principles

Technical Highlights

• 50V VOC / 8A ISC solar input → 164V LiFePO4 output
• ~300–330 W charge power with multi-rail architecture
• Isolated Hall-effect current sensing on input and output
• Every passive value derived from first principles

Deliverables

• ✓Fabrication-ready 2-layer PCB
• ✓Gerbers, drill and pick-and-place files
• ✓Fully LCSC-sourced BOM
• ✓33-page hardware design report
• ✓Firmware specification