With the EverStart MAXX BC40BE 15 Amp Automatic Battery Charger and Maintainer keeping your battery optimized is as easy as pressing a button. Just connect your battery, press the charge button, and the unit will automatically detect whether to engage bulk charging or maintenance (float) mode as needed. Additional features also include a alternator check for diagnosing car trouble. There's also a 40 Amp Engine Start mode that's helpful for getting vehicles back on the road. You use the battery reconditioning feature to help extend the life and enhance the performance of your 12V batteries. ETL certified and backed by a manufacturer warranty.