Ultra-Smart MPPT Technology - This 6v solar panel battery charger is crafted with SUNER POWER's unique Ultra-Smart MPPT technology, the innovative MPPT ( Max Power Point Tracking) allows to deliver high tracking efficiency of up to 99% and peak conversion efficiency of 98%, improving approximately 20%-30% utilization rate than other competitors. Improved 3-stages Charging - The improved 3-Stages charging algorithm (Bulk, Absorption, Float) allows to charge 6-volt battery more effectively, ensures battery is safely recharged and increases battery life and performance. Free Maintenance - The solar battery trickle charger stops charging when battery has full charge, and automatically resumes when battery has discharge, totally free maintenance. A fully-automatic, worry-free and smart solar battery maintainer. Full Safety Protections - Built-in multiple protections including over-charge, over-discharge, over-voltage, over-current, over-load, short circuit, reverse polarity, and over-temperature, waterproof and spark-proof, the battery is fully protected. Superior Quality and Material - Made of premium Grade A+ solar cells with efficiency up to 21%-30%, tempered solar glass and durable corrosion-resistant frame, withstand extreme weather conditions like UV, anti-rusting, erosion, hail, and sandstorm. SUNER POWER 6V Solar Battery Charger Maintainer, Waterproof 5W Solar Trickle Charger, High Efficiency Solar Panel Kit, Built-in Intelligent MPPT Controller + Adjustable Bracket + SAE Cable Kits