caravan motorhome solar panel

Best Solar Panel for Caravans & Motorhomes

Best Solar Panel for Caravans & Motorhomes

Having a solar panel on a Caravan or Motorhome has almost become a standard fitment in recent years due to the price of panels coming down and the abundance of DIY kits available.

Many manufacturers are fitting them as standard from factory or make it easier to connect one with pre-run wires in the ceiling or cupboards (Swift have been doing this for quite some time).  This article should give you a bit more information about how they work and ultimately help you find the best solar panel for motorhomes and caravans.

How do Caravan & Motorhome solar panels work?

Solar panels work by absorbing sunlight by means of photovoltaic cells. These cells then generate a DC current (our caravans/motorhomes mainly use 12volt DC) which gets fed through a regulator or controller box to regulate the voltage from the solar panel. This voltage can then be used to charge the leisure battery and also the cab battery in a motorhome meaning less flat batteries and more wild camping.

Solar panels do still work when its cloudy outside they just don’t give out as much current/voltage as when its sunny. This is good because even in winter your battery is being topped up and kept at its optimum, if a battery gets drained down to a few volts it can be damaged and will never give the performance it used to. 

best solar panel for motorhomes diagram

What type of Solar Panel do I need?

The majority of solar panels fitted on caravans and motorhomes are rigid 12v solar panels (aluminium framed) that are fixed to the roof (the same as on home installations), these are the cheapest and come in many sizes and outputs for your needs. 

This Eco-worthy 120W solar panel kit is a great all-rounder enough for most caravan and motorhomes. Available on Amazon with excellent reviews.

ECO-WORTHY 120W 12V Monocrystalline Solar Panel Kit
  • 🌞High Efficiency: 500wh daily output under 4 hour full...
  • 🌞Widely Use: Fits for shed, caravan, RV, boat, trailer, golf...
  • 🌞24/7 Plug In: USB controller protects your battery from...

Last update on 2021-09-08 / Affiliate links / Images from Amazon Product Advertising API

Next is the newer semi-flexible solar panels. These have a “flex” to them and can be fitted to curved surfaces, they are not exactly bendy but can help in certain fitting situations.  Also not quite as efficient as its rigid version by 3 to 10 percent. They are very discreet though as they are only about 5mm thick and don’t stand out as much as a chunky rigid panel which could help prevent it being stolen. 

caravan solar panel
Rigid Panel
solar panel on motorhome
Semi-Flexible Panel
XINPUGUANG 100W 12V Flexible Solar kit
  • 【Excellent performance】High efficiency monocrystalline solar...
  • 【Flexible】The 100w solar panel is a good choice for curved...
  • 【High Reliability】The modules can withstand high...

Last update on 2021-09-14 / Affiliate links / Images from Amazon Product Advertising API

Folding solar panels are a common option aswell, these allow the user store the solar panel away when not needed and then unfold it like briefcase to soak up some rays on site. 

This is really nice folding 12v solar panel kit. It comes with the controller/regulator and just requires the battery wires clipping on. Comes with storage bag and gets excellent reviews on Amazon.

DOKIO Foldable Portable Solar Panel 100 Watt 12 Volt Monocrystalline Solar Suitcase with Waterproof Charge Controller
  • Easy Operation: open up the folding solar panel, battery clips...
  • With high efficiency monocrystalline solar cell,Pre-installed...
  • Waterproof powerful solar panel,corrosion-resistant aluminum...

Last update on 2021-09-14 / Affiliate links / Images from Amazon Product Advertising API

Lastly are the small “battery charger” solar panels that are usually left on dashboards etc to keep the cab battery topped up over long periods. Many of these come with a cigarette lighter plug on them which can be a nuisance as some cab 12v sockets are not “live” when the ignition is off meaning no charge will get to the battery! 

solar panel for motorhomes
Folding Panel
car battery solar panel
Windscreen Trickle Charging Panel

This compact solar panel is approx 40x40cm and is ideal to put on the dashboard of your motorhome to keep the cab battery topped up.

POWOXI-Upgraded-20W-Solar-Battery-Charger-Maintainer 12v
  • 【Latest Design In 2020】: 20-watt high-efficiency single-...
  • 【Intelligent Charging and Maintenance】:External intelligent...
  • 【All-Round Protection】:The solar charger has many protective...

Last update on 2021-09-14 / Affiliate links / Images from Amazon Product Advertising API

What Size solar panel?

Once you’ve decided what type of panel suits you, you need to work out what output/size you need so that you are not using more 12volt than the solar panel can put in.  To work out what size panel you need (a solar panel output/size is measured in how many watts per hour it can supply in peak sunshine) we need to roughly work out the consumption of your van. 

For example: 

  • 5 x 6watt led lights, used for 3 hours in a day 
  • 1 x 50watt tv used for 2 hours 
  • 1 x 30watt pump used for half hour 

If we go by this usage above the calculation would be: 5x6x3 + 2×50 + 30×0.5 = 205 W/h (watt-hours) used in a day. 

On a typical day we would get about 5 hours of sun so a 50 watt solar panel would produce 5×50 = 250 W/h of energy. This  looks ideal for our usage but we must factor in energy loss through the solar regulator , cables and days when its not sunny! So it’s a tricky thing to get an exact match with lots of variables involved.

Things like alarms and trackers take energy in the background aswell as large screen control panels, control boxes, I-net and TV boosters. The rule of thumb is said to add 20 to 30% on top of your usage to dictate the size panel you need but going on experience I say double it .  The regulator/controller will never allow over charging of your battery and it also means you could connect up your cab battery (motorhomes) if you get a dual regulator. 

Solar panel regulator Truma
Truma regulator/controller

Due to the higher the output of the panel the bigger it gets you will need to have a look on your roof to see if the one you choose will fit!  Remember rooflights quite often hinge back when opened so if it’s a tight fit open them up when measuring. 

Fitting A Solar Panel

Can You DIY fit Solar Panels on a motorhome?

If you are a handy with tools yes why not. Tool wise you’ll need a drill and various sized drill bits, a 15 – 20mm hole cutter, a ladder, screwdrivers, degreaser/cleaner (to clean the roof if bonding the panels on) and probably a thick mat to kneel on on the roof especially if its aluminium or if it’s a panel van, although they are castellated they dent easy! The kits always come with instructions so you won’t get lost. 

Tips for Fitting

  • Always keep the solar panels covered when working/connecting them up as it can “spike” other electrical items in the van. Then uncover when all connected. 
  • The panels can be screwed to the roof but the prefered method is to bond to it using adhesive sealant as there will be less holes in the roof.                                   
  • You will need to buy extras! Extra cable if the amount in the kit is not enough (usually not), a gland for the solar wires to pass through into the van, adhesive sealant, inline fuse holders and fuses, ring terminals, a Sargent box solar connector if wiring into that.                                                       
  • Try and fit it with the narrow side facing forward as it the wind cant get underneath it as easily. Truma Solar kits come with “spoilers” to deflect the air over the panels for this reason. That being said I haven’t heard of one coming off before. 
  • For more info on fitting a caravan solar panel click here 

Sikaflex – 522  Solar Panel Adhesive, use this to stick the Solar Panel to the roof, available on Amazon here. There is no need to screw your solar panel down to your caravan / motorhome roof.

Sika 522 Caravan and Motor Home Adhesive Sealant Cartridge, White, 300 ml (new version)
  • NEWER VERSION: SIKA 522 has replaced SIKA 512
  • DESIGNED FOR CARAVAN AND MOTOR HOME: All-in-one sealant and...
  • SUITABLE FOR MANY SURFACE TYPES: Produces a strong, long lasting...

Last update on 2021-09-14 / Affiliate links / Images from Amazon Product Advertising API

If all that work sounds too much work a dealer will fit them for you. Time wise to fit is a tricky one as every van is different. Is it being wired to the cab and leisure battery? Is it being wired into the Sargent box? Are the wires going direct to the batteries or to a nearer control/fuse box? The dealer may give you a fixed price for fitting but as a guide about 5 hours for a single battery, less if the wiring is pre done in your van. 

 

I hope this has given you some idea as to whats involved in getting a solar panel for your Motorhome/ Caravan. 

 

If you found this post helpful you may also be interested this article  – Truma Combi Fault Codes

Disclaimer 

     Please note these are the words and opinion of the author only. Neither the author nor the website can be held responsible for any errors or omissions. You should seek professional assistance if in doubt.