Enjoy Precision Charging - An Integrated Thermal Sensor Detects The Ambient Temperature And Alters The Charge To Eliminate Over-Charging In Hot Climates And Under-Charging In Cold Climates Simple To Set Up And Use - Plug-In, Connect To The Battery, Select A Charge Mode, And Start Charging Your Battery. A Fully-Automatic, Worry-Free Battery Charger For Year-Round Use Limited 3 Year Warranty Restore Your Battery - Detects Sulfation And Acid Stratification And Restores Lost Performance For Stronger Engine Starts And Extended Battery Life Charge Dead Batteries - Charges Dead Batteries As Low As 1 Volt. Or Use The All-New Force Mode That Allows You To Take Control And Manually Begin Charging Dead Batteries Down To Zero Volts