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If you’ve made the decision to set up and install a solar panel system, you’ll likely have some questions about exactly you’re going to connect it all up. This article will step you through how to connect a solar panel to a 12 volt battery system, but let me be clear that if you aren’t sure what you are doing please seek out the help of a professional electrician. Saving a few bucks isn’t worth risking injury or damage to your property!

What You’ll Need

Whether you’re installing multiple solar panels with a battery storage array, or just a single solar panel, you’ll need a few things.

Solar panels and a battery

If you are unsure of where to start with buying the right panels, check out our solar panel buying guide.

Charge controller

This regulates the power that comes from your solar panel before it enters your battery, or array of batteries. This is another essential part of the whole solar array. It prevents your batteries from overcharging.

An overcharged battery is something to be avoided, as it can cause permanent damage to the battery, affect its lifespan, and can even be dangerous to you too!

Wiring diagram

Whether you’re using a manufacturer’s wiring diagram, or you’re having to customize things to fit your exact setup, it’s important to have an electrical diagram with you throughout the process.

Without a clear plan laid out, you’ll really struggle to correctly and safely connect up your solar panel system. Even if you’re only connecting a single panel, single battery, and controller together, having a wiring diagram will help you out so much.

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Wire comes in multiple sizes, material type, and colors. Make sure that it’s the right gauge required for your equipment.

Electrical Conduit

Some municipalities require electrical conduit.


Screwdrivers, wire cutters and strippers, etc

Mounting And Installing the Solar Panels

There are many ways to mount solar panels. I strongly encourage you to seek out the help of a professional installer. Someone who has installed thousands of panels will have picked up tricks and lessons learned from their past experience and ensure your system is installed the best possible way.


One of the most critical things that you can do is something that needs to be done before even a single screw is tightened – you need to pick somewhere good for your panels to be located

Roof Mounted

A typical single family home will have room to spare on the roof to accommodate a solar panel installation. Select a side of the house that is not obscured by trees or other structures and is facing the sun during the majority of the day to maximize the output of your panels.

Ground Mounted

You may opt to install your solar panels using a ground mounted solution. If you have a larger property or for some reason you want to avoid installing panels on your roof, this could be a great option. Be sure to avoid any areas that are shaded by trees or structures.

Connecting the Panels to Charge Controller

Now that you’ve got the solar panels of your solar power system installed, it’s time to connect your solar panels to the charge controller.

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They provide a safe interface between your solar panels and your battery – providing essential safety measures that protect you, your solar power installation, and your home, against overcharged batteries.

Wiring these should be fairly straightforward – be sure to follow the manufacturer’s instructions for locating the correct terminals.

It’s possible to fit and connect a solar panel system without the use of a charge controller if you’re using much smaller solar panels in the 1 to 5 watt range – but for most 100 watt setups, most proper guidelines will recommend that you use a charge controller.

There are two types of charge controllers, and they typically work by using either method to vary the voltage and/or current output by the solar panels.

The first type, PWM (Pulse Width Modulation), essentially works like a switch that turns very rapidly on and off to regulate the voltage and/or current. It’s a very simple technology, but of the two it’s by far the least efficient, with efficiency as low as 40% in some cases.

The other type, MPPT (Maximum Power Point Tracking), use more complex technology to track the energy in the solar setup, coming from the panel and going to the batteries.

The main upshot of this for the end user is increased power efficiency – up to 30% more efficient than similar PWM charge controllers – at the cost of increased price. An MPPT charge controller will typically be a fair bit more expensive than it’s PWM counterpart.

If you’re less concerned with the efficiency gains that you can get from using an MPPT controller, then it might well be worth saving money by buying a PWM controller – but in the long run, an MPPT controller might work out a better buy.

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Connecting the Charge Controller to the Battery

Now that the charge controller and solar panels are connected, it’s time to wire the charge controller and the battery together.

Always follow the instructions as laid out by the manufacturer of your equipment when connecting your solar charge controller to the battery – as you should do when connecting any and all parts of your solar panel system!

This should be a relatively straightforward job, just as long as you pay careful attention to the instructions as laid out by the manufacturer of your equipment.

Power Inverter

If you’re intending to use your solar power system to power devices that use AC (Alternating Current), however, then you’ll need one more component – an inverter. Seeing as the vast majority of electronic devices use AC, this is likely going to be a part of your solar panel system too!

An inverter is actually a pretty straightforward device. All it does is convert DC (Direct Current) into AC – but it’ll be one of the most important parts of most people’s setups.