RV FEATURE
HOW DOES THIS WORK IN PRACTICE ?
Fortunately , most of us have more than a single 100W solar panel on the roof of our caravan . Our van , for instance , has three 150W panels for a total of 450W .
Theoretically , they should be capable of producing 30A , but that is only under the ideal conditions mentioned above .
Typically , measured over the whole day , we would be lucky to average 15Ah per hour . If we considered our setup fairly typical , and we referred back to the power usage scenario from part one of this article ( GoRV # 42 ), in
which we used 140Ah from our battery , it would take almost 10 hours to replace that power — assuming we have no power draw
during the recharging process .
We have a compressor fridge that draws power during the day , making fully recharging the batteries almost impossible .
Compressor fridges are great but they draw a lot of power . Over-packing will reduce their efficiency .
WHAT CAN WE DO ?
Fortunately , all is not lost . The above example would be considered a fairly extreme use of available power . The truth is , when we are free-camping , we are very aware of our power needs and , as such , manage our power accordingly . We have learnt a few tricks along the way :
1 . Try to use high-power appliances , such as water pumps , during the middle hours of the day . This is when your solar panels are working at their peak and the power drain will have a minimal effect on recharging .
2 . Keep your solar panels clean . We have found , even after a few days , the wind can blow sufficient dust over our panels to reduce their charging by two or 3A . A quick wipe with a damp cloth is all it takes .
3 . Use a portable solar panel to augment your rooftop panels . We have an additional Anderson plug that is wired in parallel with our rooftop panels , allowing us to connect an unregulated panel into the system . Even a 100W panel moved during the day to face the sun at the optimal angle can boost recharging by 4A per hour . You can achieve the same result by plugging a portable panel into the Anderson plug that takes charge from your tow vehicle . Be aware that you will need a regulated solar panel if this connection is wired directly to your house battery .
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