Do you have a boat or RV? Then you need a Sunsei Solar Charger 400.

Larger vehicles such as pick-ups, vans, RVs, or small boats have larger batteries and larger battery drains simply because they have more electronics. The Sunsei 400 solar battery charger slowly charges larger 12V deep-cycle batteries, helping to protect them during storage periods. Helps maintain 12V batteries and reduce battery loss caused by key off electronic drains and natural voltage losses.

The Sunsei Solar Charger 400 is weatherproof and designed for outdoor use, and its amorphous silicon panel works well under overcast conditions. It will verify sunlight exposure at the push of a button. The ABS plastic frame won´t scratch delicate surfaces. It has built-in discharge protection and won´t discharge your battery in darkness or on dull days.

It comes with battery clamps and ring connectors, extension cable (10ft), 12V plug and socket cables and mounting screws. Maximum power 6Wp.
Nominal current: 400mA @ 15V in full sun Suitable for all 12V batteries.
Suitable for all 12V batteries.
Dimensions: 375 x 360 x 26 mm, 1.5kg.
10 year warranty on panel output; 2 year materials warranty.