Abyss On-Board Alternator Charger - The essential boat upgrade that allows you to charge your 24V trolling motor battery from your engine's alternator. While on the water, your alternator's excess power redistributes so you get an extra boost, and better battery life. The Abyss marine charger is the perfect solution for charging your trolling motor or aux batteries. DC-DC charger applies on-demand charging voltage to your batteries so they only receive the charging current they need to replace energy that has been consumed. Smart charging system also works to ensure your cranking battery voltage will not fall below 12.5V, only transferring charge when your starting battery reaches 13.3V Manufacture 2-Year Warranty