This high quality 530W 12V dual battery solar charge controller is designed to charge and protect 2 batteries simultaneously, with automatic cut off to prevent over-charging. This makes it a perfect solar controller for a caravan, motorhome, boat or any other system with 2 batteries (e.g. engine and leisure battery). The main battery will be charged with full available power, whilst the second battery will be trickle charged (max 1.5 Amps). Please note: this controller also functions with only one battery connected. In this case, 100% of the charging current will be passed to the single battery. A second battery may be added at any time.