This 40A DC to DC battery charger with MPPT solar charger has been designed for in-vehicle use where auxiliary batteries are required to be charged from solar panels or the vehicles main battery. The charger offers fully automatic, set-and-forget operation, isolating the main vehicle battery when the engine is off, preventing discharge so you can still start your vehicle when required. It provides multi-stage charging for lead acid, AGM/Gel, Calcium, LiON and LiFePO4 battery types. The in-built MPPT solar charge controller accepts PV solar panels with an output voltage range of 16-25V (minimum panel size 100W). Please note: These chargers feature a battery chemistry type lockout feature that prevents changes while the auxiliary battery is connected. Features Heavy duty aluminium case and mounting bracket Microchip monitoring and control Fully automatic high frequency multi stage charging MPPT solar regulator input Compatible with vehicles fitted with smart alternators Pulse mode technology that reduces oxidation, evens electrolyte consistency and minimises temperature equating to longer battery life Easy push button chemistry select: AGM/Gel, Calcium, LiON, Deep Cycle, VRLA and conventional flooded Lead-Acid batteries Internal charger temperature monitoring and power output control LED indicators showing state of charge Over charging, short circuit and over temperature protection Reverse polarity protection: Input reverse polarity protection and Output reverse polarity protection Thermal overload protection Solar input overload protection Power cut memory function; once selected, the charger will remain on this battery type until it is changed Instructions Specifications General Type: Multi Stage DC Battery Input: 12.5-16.0V Solar Input: 16.0-25.0V Output/Charging Voltage: 14.4 - 15.4 V (stops charging when alternator output or vehicle battery below 12.5V) DC Output Current: 40A Solar Output Current: 40A Minimum Start Voltage: 2.5V - for battery being charged Minimum Solar PV Panel Size: 100W Charge Control Soft Start: Yes Soft Charge Current: 40A Bulk Charge Voltage: 14.7V (AGM/Gel), 13.5V (Lead Acid), 15.4V (Calcium), 14.4V (LiON) Absorption: Constant voltage with automatic amperage control Float Charge Voltage: 13.5V (AGM/Gel), 14.4V (Lead Acid), 13.5V (Calcium) Float Charge Current: 100mA Battery Range: 60-500Ah Recommended Cable Cross-Section 0-1 metres: 8AWG 1-5 metres: 6AWG 5+: 4AWG