Deltran Battery Tender Jr Maintainer Charger, Model 021-0123 The Battery Tender offers much more than a trickle charger could offer. It has a brain. It's lightweight, compact, and fully automatic; very easy to use, especially in small spaces. It will keep your battery fully charged so that it is ready to go when you are! Perfect for all lead-acid, flooded or sealed maintenance free batteries (AGM and gel cell). Complete 4-step charging program (Initialization, Bulk Charge, Absorption Mode, Float Mode). Automatically switches to float / maintenance voltage after fully charging the battery. If the battery voltage drops too far under load, full charger output power resumes. Solid state two color LED indicates the stage of charger. Spark proof. Reverse polarity protected. 12' output cord. 10 year warranty Smart Microcontroller Our onboard computer assures correct level of power is sent to the battery at all times. ISM Adaptive Charging ISM (Infinite Sequential Monitoring) adapts to the battery's needs hundreds of times per second. Reversed Hook-Up Protection Battery Tender checks for a correct connection before giving power. Sparkproof Battery Tender checks for a correct connection before giving power. Quick Disconnect Harness Connect and disconnect Battery Tender Junior in seconds. Connect And Forget It Once connected, the Battery Tender manages your battery's health on it's own.