The Wagan Tech 4.0A Intelligent Charger features 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 you'll find. The 4.0A 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, trailers, RVs, ride-on lawnmowers, tractors, classic cars, auxiliary batteries, back-up power supplies, solar batteries, and more. This charger's new Winter Mode helps to maintain the battery when the temperature drops below 41°F (5°C).Fully Automatic ChargingWhether 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. This charger automatically detects the battery and its needs, then applies the optimal charge current.9-Stage ChargerPrimary Evaluation (Diagnostic), Recovery, Soft Start, Pulse, Reconditioning, Bulk Charge, Absorption Charge, Evaluation (Diagnostic), and Maintenance Charge. Primary Evaluation â The first stage in which the charger runs a diagnostic test on the battery's condition, charge, and overall health. Recovery Charge â The second stage where the charger will begin to restore a deeply discharged battery. This step is skipped if the battery does not require it. Soft Start â To protect the battery and optimize charging, the Soft Start action is applied. A slow charge current is applied to the battery then ramps up. Pulse Cycle â This action is initiated to help "knock off" sulfation build-up on the plates that may be inhibiting the battery's ability to reach full capacity. Reconditioning Cycle â Helps to prepare the battery for bulk charging and finalizes the recovery charge. Bulk Charging â This is the first stage in which the charger identifies the battery and its needs, then applies a high voltage/amperage charge to do the bulk of the charging. Absorption Charging â This is when the battery has reached ~80% of its capacity and begins to lower the input current to the battery. This is sometimes known as the "cool-down" cycle. Evaluation Diagnostic â This is the last diagnostic mode to ensure the battery is at its optimal health. Maintenance Charge â The final cycle is known as the Maintenance Charge (also known as "trickle" or "float" charge). In this stage, the battery has already reached 95%; the battery charger will continue to apply a steady current until the battery reaches 100% capacity. At that time, the charger will continue to monitor the battery and apply a charge if it detects any loss. Battery MaintainerEven if your battery is healthy, this 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. SpecsBattery Types: Lithium iron-phosphate (LiFePo4), LPF, SLA, AGM, Maintenance Free, Flooded, Wet Cell, VRLA, Gel, Lead-Acid, Vented, Deep CycleMicroprocessor ControlledInput Voltage: 100-140V ACInput Current: 0.9AOutput Voltage: 6V or 12V (nominal)Output Current: 4A (High), 1A (Low)AC Cord Length: 6'DC Cord Length: 6'Protections: Short Circuit, Reverse Polarity9-Stage Charger: Primary Evaluation (Diagnostic), Recovery, Soft Start, Pulse, Reconditioning, Bulk Charge, Absorption Charge, Evaluation (Diagnostic), Maintenance ChargeWinter Charging ModeCertifications: CE, BCOperating Temperature: 34°F - 140°F (1°C - 60°C)Size: 7.3" x 3.3" x 1.7"Weight: 1.2 lbs. Perfect for maintaining a battery when it will not be used for an extended time 9-stage charger For all standard 6V & 12V batteries including LiFePo4 | Wagan Tech 4.0A Intelligent Battery Charger