These dual battery solar controller uses advanced MPPT technology to charge two independent batteries or battery banks. The main battery is charged at high power, while a secondary battery is given a trickle charge of up to 1A. This makes it a perfect solar controller for a campervan, motorhome, boat or any other system with 2 batteries (e.g. engine and leisure battery). The main battery will be charged with a majority of the power, whilst the second battery will be trickle charged to keep it topped up and ready for use.