Posted on 07 August 2018

 Tags: blog 

During the trip last weekend it was clear that the small 70ah battery was unable to keep up with the needs of the fridge and other electrical items. Without a charge it lasts about 24 hours. One option would be to get a bigger, or second battery but I'd rather invest in a decent solar panel. This providing continuous power during the day and hopefully buffer some into the battery for use overnight.

Solar Panel 1

The camper already uses a CTEK Dual 250S charger which has both alternator and solar inputs. No need for a separate regulator - the panel can connect to it directly.

I went for a 130W flexible panel from Photonic Universe. It didn't need to be flexible as the roof is totally flat. But these are panels narrower (540mm) than the rigid type and will fit on the roof without sticking out the side. I also bought 5m of 4mm cable with MC4 connectors to match those on the panel.


Fitting

While ideal on the roof, when the lid is open it faces the ground so the panel needs to be detachable so it can be placed on the ground or perhaps on the roof of the truck.

Solar Panel 4 Solar Panel 3
I first made a frame from 25mm box section with four corner inserts left over from making the camper frame. At the back I put on some neoprene foam rubber so it sits softly on the roof.
Solar Panel 5 Solar Panel 6
From there I screwed the panel to the frame with self-tapping screws. There is a little flex remaining which I've fixed temporarily with some foam. Using a couple of 8mm rivnuts (with the bolts tightened so they face backwards) they locate into holes drilled in the panel frame.
Solar Panel 11 Solar Panel 12
On the other side, a couple of small brackets made from 25mm angle My chop-saw had a couple of clamps with bolts ideal for screwing the panel to the roof.
Solar Panel 08 Solar Panel 09
The cables entered the camper via an entry gland at the front. 5m of cable seems plently to place the panel on the ground
Solar Panel 10 Solar Panel 07
Wired to the CTEK Done!

My multimeter appears faulty and I could not measure the output wattage. Using just a voltmeter, the output looks healthy: Up to 14v in the sun, 13v or more in cloudy conditions. The fridge has been on all week, so far so good.

Another trip in a couple of weeks 😀