4.0 Amp Intelligent Battery Charger Our Intelligent Chargers feature internal circuitry which detects the battery type, current battery charge, overall battery condition, and automatically responds to optimize charging for that specific battery. With Winter and Battery Reconditioning Modes, this is the best compact charger out there. Ideally Suited for Your Needs Our 4.0 Amp Intelligent Battery Charger is perfect for maintaining and restoring your battery especially when it will not be used for an extended time. Such applications include: ATVs, Snowmobiles, Motorcycles, Watercraft (boats, jetski, etc.), Trailers, RVs, Ride-on Lawnmowers, Tractors, Classic Cars, Auxiliary Batteries, Back-up power supply, Solar Battery, and more. Our new Winter Mode helps to maintain the battery when the temperature drops below 41°F (5°C) Fully-Automatic Charging Whether you're using this on your daily driver or on a stored vehicle, you don't have to worry about over-charging or damaging your battery. Our charger automatically detects the battery and its needs - then applies the optimal charge current. Battery Maintainer You may ask if you even need a battery charger if your battery is healthy, and the answer is Yes. Our intelligent battery charger helps to maintain your battery and keep it in optimal operating condition which saves you money in the long run. Batteries need to be maintained at 100% capacity for maximum battery life.