Article from 4WDing Australia.
A few weeks back we returned from a truly amazing 4WD and camping trip on the south coast of WA. We had a brilliant time, and found some spectacular camp sites, 4WD tracks and local attractions. However, we had a few electrical issues on both our camper trailer and Dmax which were a pain at the time.
When we got home though, I found our Lifestyle Reconn R2 wasn’t charging from the solar panels, which it had been the entire trip (as that’s what kept us limping along due to the alternator charge not working). I didn’t think too much about it as the Enerdrive DCDC kept popping the breaker for alternator charge and I assumed it might have been related.
Instead, I got our awesome mobile auto electrician out and gave him a list of things to diagnose and fix, and a couple of new things to install. He spent the better part of a day doing what I’d asked (on both the camper and Isuzu Dmax), and just mentioned to me at the end of the day that the solar panel cable was damaged on the roof, and that he’d fixed it and had a hard time to getting access to the panel.
It wasn’t until a few days later, when I was trying to see what size panels we had for an upgrade down the track that I realised something was very wrong. We only had one panel, and the other was missing! Where’s my other solar panel gone?
I sent our auto electrician a message, asking how many panels where on the roof when he worked on it, and he promptly replied with 1! My first thought was that someone had pried it off and stolen it until I remembered I took a drone shot of the camper trailer the night before we left to come home, and both panels were in place. The solar was also working, as I recall checking how many watts were going into the batteries early that morning.
It came off while we were driving
The only explanation then, which is not unlikely at all, is that the panel broke off somewhere between Albany and Perth on the way home, and snapped the cables which stopped the solar working. I didn’t notice any noises, or see anything happen, but given where they are mounted you never would anyway.
I have no idea what happened to the panel, and I dearly hope it flicked off the road and out of harms way (and perhaps someone has scored a nice, free, undamaged panel). However, it could have easily killed someone, or done some nasty damage to a vehicle, or caused an accident. I haven’t heard anything, and hope it didn’t wreak havoc!
About the solar panel mounting
From the factory, Lifestyle supply one 120W panel on their Reconn R2 Hybrid Campers. The original owners purchased it like this, and installed a second, identical panel but with a different mounting method. I knew this, as they passed the information on and there was a detailed post on Facebook about how they installed it, and when.
They purchased the usual plastic solar panel brackets that thousands of people use. These particular ones were from Kogan, and you can see them here. They are a pretty standard solar panel mounting bracket, and you can get them from BCF and a heap of other stores.
They then followed the Sikaflex instructions (which you can read here), and glued the mounts to the roof of the camper trailer. The cables were then connected to the other solar panel, and the Enerdrive DCDC unit took care of the rest. The panel had been mounted for nearly two years, with a significant number of km’s under its belt prior to letting go.
Now, I do want to make it very clear that this post is done with the best intentions, and I’m not trying to shame anyone or point out mistakes but just to prevent this from happening again. I honestly believe the original owners installed the panel in a way that thousands of others do, but for a number of reasons this one let go.
Why did the solar panel come off?
Of course, I wanted to know why the panel broke off, so I spent a bit of time looking at it, and thinking about it all. Looking at the Sikaflex on the roof, you can clearly see that its been cleanly torn away. There is no missing Sikaflex at all, its literally sheered off. Now, I have a number of theories, and I’m sure they all contributed to the solar panel flying off on our way home.
Forward air flow
When you look at the way that both panels were originally installed, the major difference is what would happen to the air flow as you drive along. The installation done by Lifestyle is using aluminium angle at the front and rear of the solar panel. This physically blocks any air flow from going under the panel in a forward/reverse direction, which is a good idea, in my opinion.
The panels are mounted high enough from the roof for good heat dissipation, but it means that at 100km/h air is not constantly trying to get under the panel, and lift it off. The second panel (not installed by Lifestyle) used the Kogan solar panel corners and supports, which allow a huge amount of air to go under the panel when you are driving along, and I’m positive would be constantly trying to rip the panel off.
Both panels were mounted with about 50 – 60mm of clearance, so well and truly enough to allow air to get under and pry against it.
The second issue is that the Reconn R2 roof is not very solid. By that, I mean that the top is made from thin metal (1mm I believe) which flexes a lot. You can push down in areas and see it move up and down. It’s also not entirely flat due to the way the different sheets of metal are joined.
When you mount a rigid panel and brackets onto a roof that flexes up and down, and that isn’t completely flat, you will end up with some taking more of the load than others. You’d think that the Sikaflex would overcome this, but only if the right quantities are put in under each bracket to make it sit nice and flat.
Either way, a soft and wavy roof isn’t going to help things.
I also wonder whether the roof flexes at all each time you push it open and closed, which would stress the Sikaflex over time. I’m told the structure is only 25 x 50mm aluminium RHS, which is likely to twist a bit each time.
Incompatible bonding materials or incorrect preparation
The fact that there is no Sikaflex missing from the roof suggests to me that it never bonded properly to the plastic mounts in the first place. If you’ve ever tried to scrape silicon off something, you’ll know it doesn’t come off easily, and when it does you usually end up with some on one piece, and some on the other.
There would be nothing on the solar panel brackets, as its cleanly ripped off. I don’t know if Sikaflex is not compatible with some plastics, but there are so many different types these days that it is entirely possible.
I also don’t know whether the plastic mounts were ‘roughed up’ prior to installation. This is required to give the Sikaflex something to bite into, rather than a flat, smooth surface. Given the patterns you see in the Sikaflex, I don’t think it was done.
Looking above, there doesn’t appear to be a huge amount of Sikaflex used on each bracket. Now, I’ve had my fair share of experience with silicone and Sikaflex, and know that you don’t need much to create an insanely strong bond, but I feel there could have been a bit more applied to each bracket.
Of course, if there were some rivets or other fixings also holding the panel down, it probably would never have come off. The OEM installation uses both Sikaflex (or silicone) and rivets, and its rock solid, and this is a good fail safe.
Of course, the whole reason for going down this path in the first place is so you don’t need to drill holes in your roof, but it does make you feel better about the panel’s security.
We never inspected it
Even with the camper roof down, its well above my eye level, and without climbing on a ladder you’d never see what’s up. In the past I had a brief look at the roof, but never inspected the way the panels were mounted. I didn’t ever think that they could be a disaster waiting to happen.
Check your roof mounted solar panels
So, what’s the purpose of this post? It’s to remind people that solar panels can, and do come off caravan and camper trailer roofs.
Do me a favour and grab yourself a ladder, and check your panels out. Make sure they are mounted properly, that nothing has torn or moved so you don’t end up like us! Are your solar panels secure enough on the roof?
Solar upgrade options
So, we now have a Hypercamper with a 120W panel on the roof, and its not enough to keep up with our 82L fridge and other accessories. We made do up north recently with folding solar panels, which are a good alternative, but overall a pain in the backside to deal with.
I’d much rather fixed panels that you never have to touch, so we need to plan an upgrade. I could just purchase another Thunder 120W panel, and mount it again (differently though!), or I’m toying with the idea of removing the other panel and mounting a couple of bigger ones on the roof.
We will eventually go down the path of Lithium batteries, and I hate doing things twice, so it will be done well the first time. If we add too much more weight to the roof, I’ll have to go down the path of stronger gas struts, or actuators to lift the roof. With the two 120W panels it was OK, but any more and you’d have issues. Decisions decisions.
So, we live and learn. We’ve thrown a few hundred bucks away in the solar panel that came off, had to pay for an auto electrician and could have caused an extremely bad accident to occur. The next panels that are mounted will be done so that nothing will move them, ever.
The most important thing for us is to share this as a learning opportunity for everyone out there, as there’s a lot of Caravan and Camper roof mounted solar panels today. If you are going down the path of a Caravan Solar Panel Installation, do it so even a cyclone won’t take it off, and regularly check it!
Have you ever had a panel come off? What’s the best way of mounting them?