There are a number of elements to consider when selecting solar panels and componentry for your RV or boat.

1. Solar panel type and size: The primary consideration with panels is their physical size, weight and what you can fit where on your roof to maximise your potential solar generation. We offer 5W to 670W.
2. Solar controller and size: The Solar Controllers convert DC power voltages and solar panels into appropriate battery charging voltages. Batteries or different types require different charging regimes.

Sizing and Choosing Solar Panels

Split Module PERC

We offer a range of solar panels from 50W to 410W.

Like a roof will replenish a water tank with rainwater – to fill a battery used, a solar panel provides an off-grid DC power source to recharge the system to 100% during the day when sunlight can generate DC power from your panels.

A 220W panel, for example, has an operating voltage of 19.8V x 11.11A = 219.97W.

To replenish the 50AH used overnight the next sunny day with solar power – we can size the panels accordingly in Watt Hours or Wh.

50AH x 12V = 600Wh. So, we would need a minimum of a 200W panel operating in 3 hours of good sunlight to replenish our 50AH of used battery power.

Alternatively, 2 x 100W panels. As the weather or panels are never 100% efficient, it’s a good idea to double the amount of generation you calculated you needed or more. Panels are more affordable than ever – we recommend putting as many on your roof as your roof will fit.

We recommend doubling the battery capacity to give you a day off backup power in bad weather if you can afford it.

We commonly supply 2 x 330W panels connected to 2 x 260AH batteries to suit New Zealand weather conditions. Customers sometimes travel in large motorhomes around the South Island in mid-winter 800W solar, e.g. 2 x 440W panels (or more).

The price differential between panel sizes is now minimal. For example – a 330W panel is only $41 less than a 410W panel.

The primary consideration with panels is their physical size, weight and what you can fit on your roof to maximise your potential solar generation.

Modern large panels are split into two panels in the same frame, which is valuable if a tree shades one-half panel. For example, the other panel will provide half the total power.

Panels can be connected in series, in parallel or in combination using MC-4 branch and Y-connectors back to the controller(s).

Where you have limited roof space on a van or between the hatches and vents on a boat, you should choose the largest panel(s) that will fit the available space.

Mounting Solar Panels

We offer many mounting options. The most popular are our panel kitsets, which come in various sizes to suit small and large panels. These kitsets include the necessary MC4 cables, mounting brackets, self-tapping screws and bolts, fuse holders, cable connectors, heat shrink, marine-grade sealant, cable clips and complete instructions.

We also supply standard Z brackets with fixing hardware and a range of adjustable brackets ideal for mounting panels onto curved spaces, such as boats with curved decks and roofs.

In all instances, we recommend using an excellent marine-grade adhesive/ sealant such as SIKA 291 with self-tapping stainless screws or bolts.

Sizing and Choosing Solar Controllers

Solar controllers convert DC power voltages and currents from solar panels into the appropriate battery charging voltages and currents for a range of different battery types.

Batteries of different types require different charging regimes to charge them to the correct levels. An AGM battery, for example, may require several stages of intelligent pulse charging, whereas a Lithium may require a bulk charge at a fixed voltage.

The solar controller is programmed for the specific battery type and comes in two kinds (PWM or MPPT). MPPTs are the most modern and efficient systems. We don’t recommend PWM.

Solar controllers come in various sizes, which are determined by the total input wattage of your panels. For example, a 10A controller in a 12V system will support a maximum of 130W, a single 100W panel, or two 50W panels connected in a series.

For example, a typical RV or camper with a 12V system and 2 x 330W panels (660W) would require a 60A controller rated to 750W of panel input power.

Some large solar systems have dual controllers (one for each panel or string of panels), so if one controller fails, the other can deliver half the solar power to the battery bank. If you want extra redundancy in your system – two smaller controllers are not much more expensive than a single large controller.

Solar panels should be installed with a maximum of 3 panels in a string (3 panels connected in series) so as not to overload the controllers.

Solar Controller Brands, Types, & Accessories

Solar charge controller models vary concerning maximum input power (total panel wattage) and the type of system size, e.g. 12V, 24V, 48V. (e.g. Tracer AN series).  WPEVER Tracer AN Series is our most popular controller (pictured above).

Some models provide independent charging of dual battery systems that have a house battery and start battery (e.g. DuoRacer)

Some Models are IP333 splashproof e.g. XTRA range while some are waterproof e.g. TRACER 2606BP.  Some models are shielded in metal cases for low noise and electrical interference e.g. Tracer BN Series.

Some models have high input power ratings for large solar arrays (e.g. Studer range).

External Meters

External meters such as the Epever MT-50 allow an easy view of a larger display and more accessible programming with more buttons. They can be installed several meters from the controller to which they are connected. So, you could mount your controller next to batteries under a bed, for example and interact with the controller from a panel at the other end of your vehicle.

Bluetooth interfaces such as the eBox-BLE allow you to program and monitor your controller from your Smartphone via Bluetooth.