This is an 800 Watt Solar Panel Wiring Diagram with a complete list of DIY parts needed and kits available.
Use this as a guide to fitting your RV, campervan, motorhome or caravan solar set up.
We’ve designed the diagram so it’s simple to understand for newbies to campervan electrics.
Campervan electrics can be dangerous so if you’re not sure what you’re doing or don’t feel confident to complete a solar set up yourself, seek the help of an electrician.
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What can a 800 watt solar panel power?
How much a 800 watt solar panel can power depends on a number of variables including the time of year, the weather, your location and the type of charge controller you install.
But here’s an idea of what you might expect to get on an average day of 4 peak hours of sun with an MPPT controller.
800 watt of solar panels will provide about 240 – 256 amp hours per day.
That’s about enough to run:
- an inverter for a TV, charging laptops and a coffee maker,
- a large, energy efficient fridge,
- recharge a plenty of small devices on a USB like phones, tablets and kindles,
- run your roof vent during day and night to stop condensation,
- keep a composting toilet’s fan running 24/7,
- run a diesel heater during winter and
- switch on LED lights inside the campervan.
Bear in mind this is based on an average sun light day.
An 800w systems gives you a good few days in reserve, depending on your usage and without other sources of recharging.
If you intend living in a camper in the winter months, 800w is complete luxury!
You may not be able to replenish the batteries everyday so consider what level of contingency you need to avoid cycling the batteries more than necessary.
Who will suit a 800 watt solar panel system?
An 800 watt solar panel set up is a good size for 4 people with a large RV or camper with roof space for the panels.
Though you’ll always need to monitor usage and battery levels, with a solar system this size, you’ll comfortably have enough power to meet the needs of 4 people.
If your ideal solar system is even larger than 800w, you going to need a support vehicle just to carry your panels around!
You could consider extra juice from a portable solar panel system but that’s for another post.
800 Watt Solar Panel Wiring Diagrams
There’s a few points worth clarifying about these wiring diagrams before you get into the detail:
- The wiring diagrams shows only the supply side installation of a 600 watt solar panel system. They goes as far as charging the battery. For the load side detail, check out our post on campervan wiring.
- They exclude charging the battery from shore power or the alternator.
- This set up needs a minimum of 300 – 360ah of battery so the diagrams have 2 x 12v batteries wired in parallel.
- For more information on how to fit the batteries, see our post on campervan batteries.
- The diagrams also excludes wiring an inverter – it sits on the load side of the battery.
- The first 2 diagrams below show an 800 watt solar panel wiring diagram wired in parallel and series with 4 x 200w panel configurations.
- The 3rd diagram shows an 800 watt setup wired in a combination of parallel and series with 8 x 100w panel configurations.
- For a full breakdown of the detail, comparisons and even an interactive calculator for mixed panels, check out our complete guide to wiring your solar panels in series or parallel.
800 Watt Solar Panel Wiring Diagram in Series with 4 x 200w panels
800 Watt Solar Panel Wiring Diagram in Parallel with 4 x 200w panels
800 Watt Solar Panel Wiring Diagram in Series & Parallel with 8 x 100w panels
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DIY 800 Watt Solar Panel Parts List
This is a list of every component you need for a 800 watt solar panel set up on your RV or campervan.
The list includes affiliate links. This mean we may earn a commission from any purchase you make at no additional cost to you.
If you’re buying from Europe or the UK, use the UK link. Otherwise, use the US link.
Solar Charge Controller
Solar charge controllers regulate the current from the panels to a safe level so it can charge the batteries.
A 60-100A controller is needed for an 800 watt solar panel set up, depending on the number of panels and how they’re wired.
Use our solar charge controller calculator to double check the correct size for your set up.
At this size and investment, we recommend installing the MPPT controller.
A PWM controller is a fraction of the cost of a MPPT but the considerable loss of harvested energy would offset the cost of the larger system.
Check out our complete guide on how to select the right solar charge controller for your setup.
There’s 3 types of campervan batteries. We recommend choosing Gel or Lithium-ion.
For an 800w solar panel set up, you need around 360ah of gel battery or 300ah of lithium. These are the next closest sizes we could find.
If space isn’t a major issue, you’ll never be unhappy of a bigger battery so always go up a size rather than down.
Use our battery sizing calculators to get the right size and type for your needs:
Solar panels come with about a metre of cable so not normally long enough to reach your battery bank.
MC4 connectors are rated to cope with the current and are weather proof so you can extend the cable.
For wiring 4 panels in parallel, you need 1 pair of 4 to 1 solar branch connectors and 1 single pair of MC4 cable connectors.
For wiring 4 panels in series, you need 1 single pair of MC4 cable connectors.
For wiring 8 panels – 2 pairs of 4 in series then both strings in parallel, you need 1 pair of Y branch connectors and 1 single pair of MC4 cable connectors.
Solar Panel Cable
The point of using different colours is to easily identify the negative and positive wires.
If you can’t get red, use the black cable and mark it with red electrical tape or heat shrink.
Measure how much extension cable you need before you buy.
For both the positive and negative sides, you need enough to run from the end of the existing solar panel cables to the battery, via the solar charge controller and kill switch.
This sits between the solar charge controller and the battery cut off switch.
Bear this in mind if you’re travelling to areas where online shopping may not be an option.
When wiring in series, the fuse between the solar panel and the solar charge controller should be 1.3 times the size of the lowest Optimum Operating Current of the panels in the array (see the back of the panel for their specification).
When wiring in parallel, the fuse between the solar panel and the solar charge controller should be 1.3 times the total of the Optimum Operating Currents of all the panels in the array (see the back of the panel for their specification).
The fuse between the solar charge controller and the battery, should be the same rating as the solar charge controller.
2 x 1250 Amp Battery Cut Off Switches
Cut off switches on the battery supply line and the circuit supply lines allow the battery to be isolated.
The battery cut off switch must be greater than the total capacity of the battery bank.
If you want to upscale in the future, it’s worth fitting a larger one now to save changing it later.
Sikaflex 221 (Panel Adhesive)
Use this adhesive to secure the solar panel mounts to the van roof.
It’s a bit messy, so wear latex gloves when applying it.
You need about 4 or 5mm of sealant between the bracket and the panel for a robust bond. It takes about 24 hours on a dry day to cure.
Fuses and wires must be rated for the system’s load and cable run length. We’ve covered everything you need to know in our campervan wiring post.
800 Watt Solar Panel Kit
If you’d prefer to avoid shopping around, you can buy pre-configured solar panel kits.
They usually include the solar panel, solar charge controller and mounting brackets. Some include extension wires.
If you opt to buy a kit, check what’s included and what additional things you’ll need to buy.
And make sure it makes economical sense.
800 Watt Solar Panel Kit
This is an 800 Watt Solar Panel Kit complete with:
- 8 x 100W 12V Monocrystalline Solar Panel
- 60A MPPT Charge Controller (for a series & parallel combined configuration)
- all cables and connectors
- mounting brackets
- fuse holders & fuses.
You need to buy the cable entry housing and battery separately.
How to Install an 800 Watt Solar Panel System
Our guide details everything you need to install a campervan solar panel system.
It’s written to suit any size of system so it makes reference to how to install multiple panels.
It may come in useful when considering upscaling your set up though.
There’s also a section about the tools you need to install your campervan solar panels.
Some of these tools can be quite expensive so unless you expect to get a lot of use out of them in the future, try to borrow them where possible.
Check out our complete guide for how to use a digital multimeter in your camper.
It’s on our van life essentials list for good reason!