When solar panel and leisure battery kit is connected to a battery, the solar panels will charge the battery during the day when there is sunlight.  When the battery is full the solar panel system will continue to put through energy however it will have nowhere to be stored to so some system will automatically shut this off or if they have a MPPT ( maximum power point tracking) this will try to optimise the charging of the battery by continuing to supply power to the battery however at a lower voltage, this helps to prevent the system from wasting the excess energy.