Designed to trickle charge 12V lead acid batteries with no additional running costs. Ideal for cars that will be left standing for long periods, as well as for maintaining batteries in caravans and boats. The built-in blocking diode prevents reverse charging from the battery to the solar panel at night. The briefcase comes complete with an adjustable angle support that allows you to position the solar panels in prime sunlight. The solar panel is an amorphous receptor and is ideally suited to the northern European climate to enable the optimum use of daylight hours. It can even operate behind glass.