Basic solar charging system

[Martin P]

We would like to put a basic solar charge system on our van.
We use very little power, the truma heater runs on gas but its electric fan is probably our biggest current user. Want to put I panel on the roof ,maybe 150 watts , have got about a fifteen foot cable run to the battery. ( 1 x 110amp) . I know and trust Victron stuff so was thinking about a 75 /15 controller.
I quite like but am not definite on a flexible panel (am not putting any mechanical fixings through roof) Can anyone recommend any panels/ suppliers to use or avoid etc.
Any help or comments greatfully / amusingly received!

 

[Fisherman]

We would like to put a basic solar charge system on our van.
We use very little power, the truma heater runs on gas but its electric fan is probably our biggest current user. Want to put I panel on the roof ,maybe 150 watts , have got about a fifteen foot cable run to the battery. ( 1 x 110amp) . I know and trust Victron stuff so was thinking about a 75 /15 controller.
I quite like but am not definite on a flexible panel (am not putting any mechanical fixings through roof) Can anyone recommend any panels/ suppliers to use or avoid etc.
Any help or comments greatfully / amusingly received!

Don’t buy a flexible panel unless you have to.
Far better with normal aluminium framed panel which will last much longer, and be cheaper. You don’t need to use mechanical fittings. I used sikaflex 554. But I would not use corner mounts they don’t have a large enough surface area to improve adhesive fixing. I bought 50mm angled aluminium and bolted it to the sides of the panel, this gave a much larger surface area for the adhesive. The victron solar charger is fine, but get one with Bluetooth, this will give you greater control. You can get them for around £50-60 now victron equipment has come down in price.
Victron panels are excellent I have two small 45w Victron panels as part of my array. But take a look at Renogy and ecoworthy kits online, from Amazon or eBay.
Just sell the cheap solar chargers and fixings that come with them and use your victron which will be far better. You should get around £25 for them.
Also clean the surface before fitting with some isopropyl alcohol, this improves bonding.

Here’s a 120 ecoworthy kit on eBay, I used the 240w kit, and their stuff is excellent, and great value.

Finally if you are unsure about fitting then get advice or someone who knows what they are doing to do it.

240w Solar Panel Kit 20a MPPT Controller High Efficient for Home Garden Car for sale online | eBay

Find many great new & used options and get the best deals for 240w Solar Panel Kit 20a MPPT Controller High Efficient for Home Garden Car at the best online prices at eBay! Free delivery for many products!

www.ebay.co.uk

Here’s mine 2 ecoworthy 120w panels, with two victron 45w panels at the rear.

 

[Obanboy666]

Deffo you don’t need mechanical fixings for the solar panel.
The factory fit panel on my Pilote was just bonded to the roof, I followed suit when fitting a second panel. Went onto the Sikoflex website to determine which adhesive to use, cannot remember which one it was unfortunately. Abraided the surface and used the cleaner/ activator recommended by Sikoflex. As Fisherman states don’t use the plastic corner mounts, I also used 50mm x50mm Ali angle, abraided to get a key for the adhesive. Panel was on roof for the 3 years I owned the motorhome with no issues.
Victron solar controller every time for me, not cheap but you get what you pay for imho.

 

[1 Cup]

I got 100w panel for £69 .00 so less than £1 for 1 watt. My Craig panel which fits in roof space 260w panel was £170 each x3. EBay. The smaller the panel plastic corners are good . Clean roof add stuff from screw fix £5 and put some weight on it . I put my spare wheel top 24 hour. On bambi.

Look at the curve at front of van and make sure the top of the front edge of panel is 6 inches farther back, wind resistance.

But go big or by twice. That includes the controller so about £300 for hardware. £30 wire included.

 

[Martin P]

Thank you all for your help. Ally angle seems a great idea. Im basically looking for about 15 to 20 amps a day

 

[trevskoda]

Here you go for brackets, panels cheap as chips ebay, try a votroning regulator which will send a 1amp charge to starter battery.

 

[Fisherman]

Deffo you don’t need mechanical fixings for the solar panel.
The factory fit panel on my Pilote was just bonded to the roof, I followed suit when fitting a second panel. Went onto the Sikoflex website to determine which adhesive to use, cannot remember which one it was unfortunately. Abraided the surface and used the cleaner/ activator recommended by Sikoflex. As Fisherman states don’t use the plastic corner mounts, I also used 50mm x50mm Ali angle, abraided to get a key for the adhesive. Panel was on roof for the 3 years I owned the motorhome with no issues.
Victron solar controller every time for me, not cheap but you get what you pay for imho.

Sikaflex 554 is recommended for solar panels.
It requires no bonding agents or activators and whereas other adhesives can become unstable over time 554 remains stable for decades.
But I choose to use some isopropyl alcohol after cleaning the surface, but this is not absolutely necessary.
It is inexpensive at around £6 for 250ml.
It's also used for cleaning spectacles, and a 250ml bottle can be bought for about £7.

 

[trevskoda]

Sikaflex 554 is recommended for solar panels.
It requires no bonding agents or activators and whereas other adhesives can become unstable over time 554 remains stable for decades.
But I choose to use some isopropyl alcohol after cleaning the surface, but this is not absolutely necessary.
It is inexpensive at around £6 for 250ml.
It's also used for cleaning spectacles, and a 250ml bottle can be bought for about £7.

Dont mention alcohol on here or you will have half the crew outside you van.

 

[Martin P]

Thanks . I see ecoworthy are doing 2 x 195 watt panels plus pwm for £210.
Seems too good to miss.
I could upgrade to victron controller later

 

[Martin P]

Just ordered the 2 ecoworthy 195 watt panels.
Mostly because they will fit nicely on the roof.
Thanks again for all your help

 

[trevskoda]

Thanks . I see ecoworthy are doing 2 x 195 watt panels plus pwm for £210.
Seems too good to miss.
I could upgrade to victron controller later

Pwm controlers are old hat so forget that, you require a MPPT unit which in fact will give a third more power and go into float mode,& cycle, a good controler will cost from £60 up to £150

 

[Martin P]

Wow. That 554 is 25quid a tube.
How many tubes for 2 panels on ally angle?

 

[Martin P]

Pwm controlers are old hat so forget that, you require a MPPT unit which in fact will give a third more power and go into float mode,& cycle, a good controler will cost from £60 up to £150View attachment 133811

Yes but presumably I can upgrade to an mppt anytime later

 

[Fisherman]

Wow. That 554 is 25quid a tube.
How many tubes for 2 panels on ally angle?

Well screw them down then but that would require 8 holes per panel. One tube fitted 2 120w panels. I think the angle aluminium was about £40 for four 1m lengths. You can use the cheaper sikaflex about £12 a tube, but it may degrade over time.

 

[Fisherman]

Just ordered the 2 ecoworthy 195 watt panels.
Mostly because they will fit nicely on the roof.
Thanks again for all your help

That’s a lot of solar for one 110a battery. You will need the Victron 100/30 solar charger to handle that amount of solar. They’re on Amazon for £99.
But if you are only charging a 110 battery with 390w of solar the cheaper charger would do. But the victron MPPT is a much better controller.

 

[Nabsim]

I believe there are different plastic mounts, the ones I used are solid so quite a bid contact area. On my 150W panels I used 4 plastic corner mounts plus two plastic centre mount on each panel and the Sikaflex that Sika Tech dept advised after I told them what the van construction was (I think it was 521 Architectural but too long ago for me to remember, it was £24 a tube back then though )

 

[trevskoda]

Yes but presumably I can upgrade to an mppt anytime later

Do it once do it right, batteries last longer and charge better with a MPPT, these and many will allow you to go from say lead carbon to lipo4 with a flick of a switch if you upgrade, forget standard so callled les batteries or sealed gels as almost as expensive as ones i have stated.

 

[wildebus]

For Glass panels, my default choice are the "Z Brackets" (examples here - https://amzn.to/3SF8y0n ).

I have used those on lots of vans, including my last two. Very adaptable and have bolted to rails with Coachbolts in some cases and stuck down with Sikaflex in others. I actually removed one of the panels I fitted last week that had the Z Brackets and was stuck down with Sikaflex 522... It was not going anywhere on its own and I ended up needing to use a multitool to cut the bond between the sikaflex and the bracket.
IMG_20240729_093114_505 by David, on Flickr
You can see the Sikaflex pads still there and very well adhered to the roof after cutting away under the brackets.
(as an aside, why does it get so green and manky UNDERNEATH Solar Panels?)

I see Trev posted about these as well. Apart from his appalling idea of buying from Temu (NEVER buy from Temu!), he is right about the bracket (not the Votronic controller though )

Not a big fan of the big plastic mounts - they take so much space up and are expensive. Personally I only use these when adding to an existing solar setup that uses these to keep the same aesthetic appearance.

Flexible panels can be ok, but only if you get decent ones. And decent ones cost around 3 times of glass panels at least. Last two sets of panels I fitted happened to be flexible ones oddly enough, but that was because wanted as much solar as possible and the available space around the vents, etc meant no glass panels available that would suit.
Malibu - Front by David, on Flickr

Well screw them down then but that would require 8 holes per panel. One tube fitted 2 120w panels. I think the angle aluminium was about £40 for four 1m lengths. You can use the cheaper sikaflex about £12 a tube, but it may degrade over time.

My Neighbour over the road has an Autosleeper PVC. She wants to upgrade her solar and I had a look ... one panel positioned right in the middle of the roof, so would need removing .... got four brackets securing the panel and it looks like EACH bracket is secured to the metal roof with FOUR screws! . If I do do any solar upgrade for her, I will not be removing those brackets!!

I believe there are different plastic mounts, the ones I used are solid so quite a bid contact area. On my 150W panels I used 4 plastic corner mounts plus two plastic centre mount on each panel and the Sikaflex that Sika Tech dept advised after I told them what the van construction was (I think it was 521 Architectural but too long ago for me to remember, it was £24 a tube back then though )

Sounds similar to this Burstner? Used a mix of Corner and Centres depending on what fitted.
Additional 120W PV Panel by David, on Flickr
I used 522 Sikaflex, which is the recommended updated for the now obsolete 521 I think. Depends how you buy, but currently I think it is around £13 a tube posted out if you buy multiples.

 

[Nabsim]

Looks similar including the grime David lol. This shows the centre ones I used on all the ‘long’ sides

 

[Martin P]

Well thank you all for the advice.
I have ended up buying the ecoworthy 390 watt kit plus some sika 544 adhesive.
For £210 for the kit although it will provide a lot more power than I need I will fit it with the pwm controller that comes with it for now and see how it goes on our annual Scottish trip this year. Later on when our single battery needs replacing, if we find our power requirements have grown it will be an easy job to fit an Mppt controller and another battery.