The BMPRO Pro Boost 40 DC-DC battery charger features 40A max input, enabling fast and efficient charging of a secondary battery using solar panels and/or a 12V electrical system from a towing vehicle. Highly suitable for lithium batteries, it provides a much faster charge rate than other DC-DC chargers, by blending both solar and alternator charging, ensuring your batteries stay charged. Suitable for lead-acid and lithium LiFePO4 batteries. The ProBoost40 has an ultra-thin design, making it suitable for installation in small spaces, and is resistant to vibration, as well as wet, dusty or muddy environments. A range of protective features built into the ProBoost40, such as over temperature, over voltage and under voltage protection, will guard your charging capacity. Dimensions 183mm x 130mm x 43mmInput Voltage 9-18V DCSolar Input Voltage 10-32 VMaximum Input Current 47AInput Fuse Rating 60AContinuous Output Current 40AOutput Fuse Rating 60AMinimum Start Voltage (Lead-Acid) 4VMinimum Start Voltage (LiFePO4) 0VStandby Current 15mABattery Chemistry STD, Gel, AGM, Calcium, LiFePO4Operating Temperature -20°C to 80°CIP Rating IP66 Charge Type 3-StageMaximum Voltage (STD) 14.4VMaximum Voltage (Gel) 14.1VMaximum Voltage (AGM) 14.7VMaximum Voltage (Calcium) 15.3VMaximum Voltage (LiFePO4) 14.5VFloat Voltage (STD) 13.4VFloat Voltage (Gel) 13.5VFloat Voltage (AGM) 13.4VFloat Voltage (Calcium) 13.6VFloat Voltage (LiFePO4) 13.6V Turn On Input (Standard Alternator) 13.1VTurn On Input (Smart Alternator) 12.0VTurn Off Input (Standard Alternator) 12.8VTurn Off Input (Smart Alternator) 11.8V A DC-DC charger is better for charging a battery because it can efficiently convert a higher or lower DC voltage to the voltage level required by the battery