Solar Charge Controller

A solar charge controller regulates the current and voltage from photovoltaic panels to safely and optimally charge storage batteries while preventing overcharging, deep discharge, and damaging voltage fluctuations. Two main technologies exist: PWM (Pulse Width Modulation) for smaller systems and MPPT (Maximum Power Point Tracking) for medium to large systems. Internally it comprises an input protection stage, power switches (MOSFET or IGBT), current and voltage measurement circuits, a microcontroller implementing the charging algorithm, and load outputs with overcurrent protection. Common failures include burnt power MOSFETs, faulty current shunt sensors, defects in battery voltage measurement circuits, software issues in charging profiles (Bulk, Absorption, Float), and damage from lightning strikes. Expert repair involves precise testing of measurement circuits, replacement of power components with appropriate thermal ratings, voltage and current calibration, firmware updates, and full charging cycle testing with real batteries to ensure safe and long-term performance.