MAXIMISING YOUR SOLAR POWER - 12Volt RV Solar Panels vs 36Volt Household Panels.

RV Panels (12 Volt) solar panels sizes available can go up to 300w claimed power - However during testing at 25 Degrees Celcius at Sea Level  these panels prove to produce much less power than claimed - Our testing below shows 2 x 150w Solar Panels  Produces - 125w - or  9.5 AMPS per hour after the Solar Regulator has corrected the voltage to the required  13.2 Volts (Charging voltagle).

 

Household Panels (36 Volt) run at higher voltages resulting in less resistance through the cells - Improving performance dramatically -In our testing a single 390w Panel produced 295w or 20 Amps per hour at 13.4 volts. Almost Double the output figures of a 12 Volt equivilant of similar size and weight.



THE EXPLANATION

Low Voltage is Like Low pressure in Water Systems. Low pressure/Voltage or 'Potential Difference' Means that the further the Power has to go through the cells and wires - the less power ends up getting to the battery. Increase the voltage and you increase the pressure. Increasing the Voltage also helps the power get through shaded spots etc on the panels... 

 

THE RECCOMMENDATION

If your Off grid Energy source relies heavily on solar power - Run Household panels and in turn run household quality Solar Regulators. (NOT RV SPEC DC/DC all in one under bonnet chargers)

 

My Own preference is to run household Voltage panels and combine them with  Victron components to get major power improvements over traditional RV Panels. The Victron Gear has major advantages - its plug and play design is simple to install and all display panels etc are Bluetooth (Iphone) run. More on Victron here  

Whats the best way to fit a Solar Panel to my roof top tent?

You can't just stick a solar panel  to your vehicles roof. (there is no base to fix too.)  Slimline glue down panels get too hot to quickly to be any use at all - They also tend to be 12 VOLT panels - (See Above) , DO NOT USE plastic block mounts you can buy  - These point load roof tents roof structure and can cause major leaks and damage.

Tough Touring Solar Kits - why are they the go for caravans and rooftop tents?


While we experimented with 50x50 aluminium angle - we needed a wider footprint to get a good bond surface for adhesives to connect - so we designed 2m long single rail mounting plates - with a 70mm wide base providing a great adhesive surface. 

 

We started to make them commercially, in volumes that make them affordable :)  Our Solar mounting Kits are available to purchase here - "Tough Touring Solar Kit"

 

Mounting points are at high points on the roof top tent roof - they can also be fitted on the high side of corregation roof on caravans -  preventing potential water ingress.

Check them out in the video on this page above. 

We presently make kits to suit: 

  • Camp King

  • Eezi Awn Stealth and Blade

  • Bundutec King and Standard Bundutop

  • Moremi Sport

  • The Bush Company Alpha and Black Series tents

  • Conqueror Trailers (UEV 490, 440 and Lightning Models.

  • Most caravans also would benefit from decent solar mounting systems. 

HEAD TO HEAD TEST RESULTS: 

12 VOlt RV Panels - Vs 36 Volt Household Panels - Both Tested same battery 10 mins apart at 25Degrees Celcius. Same VICTRON REGULATOR. 

12 VOLT Panels Wired together - Claimed Wattage 300w
Actual Max Watts during test - 126w
Charging current 9.3am at 13.2  VOLT

36 VOLT Panel (Single panel) - Claimed Wattage 390w
Actual Max Watts during test - 275w
Charging current 19.8Amps at 13.49 Volt

The 12 Volt set up with Mounts we install weighs in at 19Kgs - 
The 36 Volt Single panel with mounts is 21 Kgs. 

CONCLUSION: 
Double your power. Or Halve your weight.  Use 36 Volt Panels and Quality Chargers that offer High performance products... We prefer Victron Solar Regulators and DC chargers ... They are simple, powerfull plug and play, adaptive to new additions and well priced.
 
36 Volt Panel Installed on a Bundutop.jpg

TEST  1 - 36 VOLT PANEL

Picture above is of a 390w Longhi Household Panel. This panel runs at 35 Volts -  Requiring a 'Household Spec' Solar Regulator like a Victron Smart MPPT Regulator to bring that voltage down to charge your batteries.  In testing here on the same day as the below twin 12 Volt panels The 36Volt panel delivered a massive 19.8 AMPS per hour at 13.49 Volts - Around DOUBLE the figures achievable with Any 12Volt RV panels weve seen.

36 Volt Household Panel figures 25 degrees celcius.jpg
12 Volt Twin Panel set up to suit RV Solar regulators like Redarc.jpg

TEST 2 - Twin 12  VOLT PANELS

Picture above is 2 x 150w RV Panels -  These Panels wil have an operating VOltage of approx 20 Volts - Suitable for CTEC, Redarc, Projecta and many other RV style of Solar Regulators and Battery Management Systems. 
. In testing here on the same day  (10mins apart) The twin 12 Volt panels delivered a 9.3 AMPS per hour at 13.2 Volts - Around HALF the figures achievable with  36Volt Household panels.

12 Volt Twin Panel Max Figures during testing.jpg
We used a Victron 100/20 Solar Regulator on Both the 12 and 36 Volt panels as a 'control' for our tests... The Figures Photgraphed above are pictures of my iphone screen, Showing  the Victron Smart Phone App, a Free Download that comes with their chargers - It displays your battery charge, voltage, power in and out all on your phone via Bluetooth... The app syncs in to your chargers... They also work in with DC/DC chargers, Inverters, Display panels, 240 Chargers - You name it they probably do it. 
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