Connect Solar Panel to Charge Controller: 3 Steps (w/ Videos)

In this guide I’ll show you how to connect a solar panel to a charge controller in JUST 3 steps.

To help you out, I’ve made a wiring diagram and step-by-step videos. Follow along and your charge controller will be wired and set up properly in no time.

Here we go:

Materials & Tools

Materials

Note: I’ve sized the materials for my energy needs. You can copy them as-is or adjust as necessary.

Tools

  • Screwdriver

Step 1: Connect the Battery to the Charge Controller

Note: These installation instructions should not supersede those in your charge controller’s or battery’s manual. Where these instructions differ from your manual’s, follow your manual!

Check out the wiring diagram to see how to connect a solar panel to a charge controller:

Here’s the important thing to know:

Connect the battery to the charge controller FIRST. Then you connect the solar panel SECOND.

If you do it in the wrong order, you can damage the charge controller. And that just wouldn’t be any fun.

Ok! Let’s connect this battery.

Connect the negative battery cable to the “-” battery terminal on the charge controller. Connect the positive battery cable to the “+” battery terminal.

Now connect the battery cables to the battery terminals. Connect negative first, then positive.

Your charge controller should turn on or light up. For instance, mine has a light labeled “BATT” that turns on when the battery is properly connected.

Your battery is now connected!

Step 2: Connect the MC4 Solar Adapter Cables to the Solar Panel

This step takes all of 20 seconds to do.

Locate the MC4 connectors at the ends of your solar panel’s cables. There’ll be a male and a female one. They’ll look like this:

Connect the MC4 inline fuse and positive solar adapter cable to the positive solar panel cable. Connect the negative solar adapter cable to the negative solar cable. Don’t let the exposed wires touch!

Didn’t I say it’d take all of 20 seconds?

On to the final step!

Step 3: Connect the Solar Panel to the Charge Controller

Your battery is connected. ✅

Your solar panel wires are ready to go. ✅

Now it’s time to do what you came here to do — connect solar panel to charge controller!

Connect the negative solar cable to the “-” solar terminal on the charge controller. Connect the positive solar cable to the “+” solar terminal.

Note: On some charge controllers, the solar terminals are labeled “PV.” This stands for “photovoltaic,” which refers to the method of producing energy using solar panels.

Like before with the battery, the charge controller should light up or somehow indicate that the solar panel is properly connected.

At this point, consult your charge controller’s manual to see if you need to program it at all. You may have to indicate your battery type, voltage, or other details.

Fortunately for me, my controller’s default settings matched my system’s specs, so I didn’t have to change anything.

And that’s it!

Now you know how to connect a solar panel to a charge controller! 🥳

Whenever you want to disconnect your solar panel, be sure to do everything in reverse order: disconnect the panel first, THEN disconnect the battery.

Put your solar panel in the sun, and let it charge your battery with free solar energy. Relax and daydream about your next DIY solar power project.

Tip: If you want some ideas on how to add on to this setup, check out my tutorial on making your first solar panel system.

Solar Panel to Charge Controller Wiring FAQ

1. Why do I need solar adapter cables?

Your solar panel’s cables likely come with pre-attached MC4 connectors. MC4 connectors are great for connecting two solar PV wires together…

…but they can’t connect to a charge controller. So we need solar adapter cables.

Solar adapter cables have an MC4 connector on one end and are stripped at the other. That way, you can connect the MC4 connector to the solar panel cable and then connect the stripped end to the charge controller.

2. What if my solar panel doesn’t have MC4 connectors?

Buy some solar adapter cables with the connectors that match the ones on your solar panel wires.

If you can’t find any, you might have to make your own by cutting two lengths of solar PV wire, stripping both ends, and crimping on matching connectors.

3. Why isn’t my charge controller lighting up/turning on when I connect my solar panel?

Your panel probably just needs some sun!

Put it outside in direct sunlight. Your charge controller should light up or somehow indicate that the panel is properly connected and the battery is charging.

If that doesn’t work, check your charge controller’s manual for troubleshooting.

Share This Article
Share on pinterest
Share on facebook
Share on twitter
Share on email
Share on print
Alex Beale
Alex Beale
Hi, I'm Alex. I started Footprint Hero to help people reduce their environmental impact. My current obsession is DIY solar power projects, which I've been building since 2020.
Alex Beale

Alex Beale

Hi, I'm Alex. I started Footprint Hero to help people reduce their environmental impact. My current obsession is DIY solar power projects, which I've been building since 2020.

Share This Article

Share on facebook
Share on twitter
Share on pinterest
Share on email

Contents

16 thoughts on “Connect Solar Panel to Charge Controller: 3 Steps (w/ Videos)”

        1. The PV terminals are where you connect the solar panel. PV stands for “photovoltaic” which is basically another way of referring to solar energy. Added a note in the post clarifying this.

  1. Hello thank you for the clear information! I plan on running a similar rig but wondered how best to direct the cables off/over my roof down the side of a wall for occasional battery charging. Do I need to shield the cables in a housing or elevate the cables off the roof itself?

    1. You’re welcome! Good question, but I won’t be of much help unfortunately… So far I’ve only built ground- and wall-mounted installations so I haven’t looked much into this topic yet. There are “entry glands” like the SolaDeck for getting the wiring from roof to attic, but that’s about the extent of my knowledge here. (I’m assuming you’re mounting your panel to the roof of your house.)

      Though if you only need your solar setup for occasional battery charging then maybe you don’t need to roof-mount your panel(s)? Maybe just keep it in storage until you need it? That could save you time/money on installation.

    1. No, if it has the charge controller built in you should be able to connect it directly to the battery. I’d double check the manual that came with it, there’s probably an “Installation” section with instructions.

  2. Mr. Beale, I have tried 3 controllers on my RV. All have arrows going from the panels to the battery but do not have arrows from the battery to the load. When I put a load on it, it lasts about 30 seconds. This is my 3rd RV I have installed solar, the other 2 worked fine. I am at a total loss, any thoughts. Thank you, Jim.

  3. I have 3 solar panel 100 watts 12v. each and 30 amps solar charger control how many ampshour battery should i use for 2kw inverter .?

    1. Thanks for your question, Victoriano. Unfortunately — and despite the fact that I love discussing anything and everything solar! — because I’m so busy at the moment, I’m currently not doing any one-on-one advising. Thanks again and good luck with your solar power system!

Leave a Comment

Your email address will not be published. Required fields are marked *