Flat cover graphic titled ‘Solar Charge Controller Guide (2025)’ featuring a panel, MPPT controller, and battery in Solar Craftsman brand colors.

DIY Solar Charge Controllers: Sizing & Installation Guide for Tiny‑Home and Van Systems (2025)

Introduction A solar panel on its own is a “dumb” power source. Voltage can spike on bright, cold mornings and sag under cloud cover, wrecking your batteries in the process. A solar charge controller is the brain that keeps everything in check—regulating current, protecting batteries, logging data and even starting backup generators automatically. If you…