Installing a solar panel on to a pop-top

[t0mb0]

Hi,

I have a T6 with a Reimo Easyfit pop top. I want to add a large flexible stick-on solar panel to the pop-top so I'm not reliant on hookup. How have people who have done this run the wiring? I don't want to have wiring run inside the canvas as I have kids sleeping up there and I don't want them kicking the wiring around. Because of this, I assume I have to run the wires down outside the canvas at the back, but how do I avoid getting the wiring trapped in the poptop as it comes down? Do I need some curly retractable cable or something?

With regard to the junction box on the panel, I'd much rather get a bottom mounted one as it would be neater and lower profile but I've measured and I don't think it would fit in the short space between the poptop canvas and the back edge. I guess I'll have to get a top-mounted junction box and drill the wires through the pop top.

Has anyone got any tips on how to install these panels neatly?

Thanks very much,

Tom

 

[Floor Fit]

Not too many options with the junction box, but I put the cables in flexible conduit on the inside of the canvas ..no problems with my two boys who sleep up there ( so far ). Conduit stops the wires kinking also .

 

[t0mb0]

Not too many options with the junction box, but I put the cables in flexible conduit on the inside of the canvas ..no problems with my two boys who sleep up there ( so far ). Conduit stops the wires kinking also .

Is the conduit close to the canvas? We've currently got three of them squished up there so someone will definitely end up kicking it!

 

[Floor Fit]

Is the conduit close to the canvas? We've currently got three of them squished up there so someone will definitely end up kicking it!

No not overly wouldn't worry if they kick it as the cable is of descent gauge , when it folds down it goes to one side, if you make the conduit longer than needed it naturaly bends one way .

 

[travelvolts]

I bring the cables in through the pop top (2 x 5 mm holes) and then make a 20 mm hole just forward of the tailgate hinge to get into the vehicle. If you have barn doors it's even easier as you can use the blanking grommets in the tailgate hinge holes.
I beleive that others have run the cables down to the rear light and entered there.

 

[t0mb0]

I bring the cables in through the pop top (2 x 5 mm holes) and then make a 20 mm hole just forward of the tailgate hinge to get into the vehicle. If you have barn doors it's even easier as you can use the blanking grommets in the tailgate hinge holes.
I beleive that others have run the cables down to the rear light and entered there.

Thanks for the reply, that's helpful. Is the location of the holes such that, with the pop top down, the cables are entirely covered? How do you prevent the cables getting trapped in pop top? Our pop top has almost a foot of lift at the back so there will need to be quite a lot of slack.

Also, where are you actually located in case we need any work doing?

 

[Mark Woodhouse]

All good advice guys, what panel is best to go for and how do you wire this into the leisure battery, I trust this goes smart management device?

 

[Wongo]

Get the best panel you can, visit RoadPro website for technical info, the quality of the regulator is also key, we don't have endless sunshine so every bit of efficiency is vital.

 

[travelvolts]

If you lay the cables in a curve they naturally fold down in the space between the edge of the roof and the canvas. We are in Kidderminster. Check our website for quality panels and controllers travelvolts

 

[Davenjo]

I have a 100w PV Logic flexi panel on the roof which has the cable exit beneath the panel - this makes for quite a neat installation. There is then a hole through the pop top roof (beneath the panel so out of sight but also outside of the canvas) with a loop of cable to cope with rise and fall of roof - as above this folds itself neatly. The cable is then fed through the velcro opening in the rear of the canvas (SCA 194) and into the van below.

However, whilst the installation looks neat I am not convinced it is doing an awful lot!!

I had the system installed on the expectation that I would be able to run my fridge (Waeco CRX65) indefinitely but I am still finding that after 2 or 3 days on max the battery drops below the required voltage to run the compressor. Initially I put this down to the winter and limited sun but now I am not so sure.??

The van lives on the drive at home and, whilst not in full sun all day, it does get it pretty much from sunrise until about 2pm at this time of year. We came back from a trip to Ullswater last week and the leisure battery was fully charged, i.e. green light on solar controller (picture below) flashing. After leaving the fridge on for a couple of hours after we got home until it was unloaded the green light on the controller had gone to solid. Everything in the van has been switched off since we arrived home and the van has not moved. Whilst there has not been a lot of sunny days over the last week we have had some sun and this morning was sunny all day here, consequently I would expect to see the green light flashing to say the battery was now full again.

@travelvolts - does the above sound a bit iffy to you or are my expectations too high??

NB. I only have a 70ah Banner AGM battery owing to lack of space where it is positioned under the drivers seat alongside my Eberspacher heater but would still expect the solar panel to keep it topped up when nothing is running??

Cheers,

Dave.

 

[travelvolts]

Did you say that you have the fridge on full? If so this might account for some of the problem. The other thing is that solar panel, I have never seen anything like it! Do you know what make it is? Also, the wiring to and from the controller doesn't appear to be up to spec.

 

[Davenjo]

Did you say that you have the fridge on full? If so this might account for some of the problem. The other thing is that solar panel, I have never seen anything like it! Do you know what make it is? Also, the wiring to and from the controller doesn't appear to be up to spec.

Yep, fridge on full.

The panel is made by PV Logic - this one:- 100 Watt Panel Kit (black)

I'd seen these panels at a couple of the NEC shows and they seemed to be very good which was why I was happy when I realised my convertor was using the same.

 

[t0mb0]

Looking at the spec for your fridge, I would expect it to draw an average current of around 1 Amp (to maintain a temperature of 5 degrees given 25 degrees ambient). Looking at the spec of your solar panel, I would expect it to produce on average, (over the course of a full 24hr period) assuming 50% capacity over 8hrs of daylight - around 1.3 Amps. Therefore, according to this (very rough!!) back of the envelope calculation, it might just power the fridge but it's pretty tight. Obviously, in practice, this could vary wildly with amount of sunlight, ambient temperatures, fridge settings, etc etc etc so I wouldn't be surprised if it's not quite breaking even in reality.

 

[Floor Fit]

Can you not up the size of the batt so when the solar is charging you get more storage from
It ? I'm running a 110ah , the fridge,( 50 l version of yours ) is on full permanently ( while it's summer ) I was using a 75 ah but the one I now have is only a little bigger in phisical size ... @travelvolts will help you with a better battery that will fit im sure

 

[t0mb0]

Actually, my borderline-breakeven estimate might be a bit optimistic. I've just looked more closely at the controller and it's a PWM (rather than MPPT) type so it won't be able to step down the voltage whilst preserving power. Given the nominal voltage of the panel is 18v and the battery will require up to 14.4v most of the time to charge then on sunny days it's likely you'll lose somewhere in the order of 20% of the power.

 

[Davenjo]

Can you not up the size of the batt so when the solar is charging you get more storage from
It ? I'm running a 110ah , the fridge,( 50 l version of yours ) is on full permanently ( while it's summer ) I was using a 75 ah but the one I now have is only a little bigger in phisical size ... @travelvolts will help you with a better battery that will fit im sure

It doesn't seem like the system is ever fully charging the battery, i.e. when on hook-up for a while or after a long journey the green light on the charge controller flashes green - from a reasonable state of charge (solid green indicator) after a few days with reasonable sun and nothing switched on I would expect the light to start flashing?? I might talk to the people who supply the panels for advice.

In reality we will spend most of our time camping on hookup but was hoping to be able to leave the fridge switched on whilst on the drive without plugging in.

 

[Davenjo]

Actually, my borderline-breakeven estimate might be a bit optimistic. I've just looked more closely at the controller and it's a PWM (rather than MPPT) type so it won't be able to step down the voltage whilst preserving power. Given the nominal voltage of the panel is 18v and the battery will require up to 14.4v most of the time to charge then on sunny days it's likely you'll lose somewhere in the order of 20% of the power.

Is it worth looking at getting a different controller?

 

[t0mb0]

Is it worth looking at getting a different controller?

It might help a little but first I think it's worth discounting whether something is fundamentally wrong with the set up. If it's not even managing to charge the battery effectively even with nothing turned on, maybe some aspect of the setup is not functioning correctly. Can you get hold of a multimeter and measure the input/output voltage of the controller?

 

[Davenjo]

It might help a little but first I think it's worth discounting whether something is fundamentally wrong with the set up. If it's not even managing to charge the battery effectively even with nothing turned on, maybe some aspect of the setup is not functioning correctly. Can you get hold of a multimeter and measure the input/output voltage of the controller?

Probably worth buying a cheap one? Would it just be a case of pushing the probes into the input/output terminals?

 

[travelvolts]

It would help if you turned the fridge down a bit, it doesn't need to be on full!