I have been building a Steam Punk Solar Controller for our van since we moved to our house in Queensland two months ago. It is built from three blue elm wood chopping boards held together with antique hinges. It allows you to direct power from a solar panel and the alternator to the main or 2nd battery. Hopefully it will deliver enough juice to power my heavy old laptop next time we are on the road in Australia.
The next job will be to attach the new 100 watt solar panel to the roof of our van. Until then there is enough light coming through the window to power our music system.
Update: Control Panel