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

In this guide I will show you how to connect a solar panel to a charge controller in just 3 steps.

To help you, I made a wiring diagram and step-by-step videos. follow it and your charge controller will be wired and configured correctly in no time.

here we go:

materials & tools

materials

note: I have sized the materials for my energy needs. you can copy them as is or adjust them as needed.

• hqst 100w 12v solar panel
• renogy wanderer 30a solar charge controller
• expertpower 12v 33ah lead acid battery
• renogy battery for charging controller tray cables
• littelfuse inline fuse holder with properly rated fuse (or anl fuse set with renogy fuse leads)
• renogy solar panel to charge controller adapter cables
• mc4 inline fuse

tools

• screwdriver

step 1: connect the battery to the charge controller

Note: These installation instructions should not replace those in your battery or charge controller manual. where these instructions differ from your manual, follow your manual!

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

This is the important thing to know:

Please 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 fun at all.

good! 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 “+” terminal of the battery.

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

Your charge controller should turn on or light up. for example, mine has a light labeled “batt” that comes on when the battery is properly connected.

your battery is already connected!

step 2: connect the mc4 solar adapter cables to the solar panel

this step takes 20 seconds.

Locate the mc4 connectors on the ends of your solar panel cables. there will be a male and a female. they will look like this:

connect mc4 inline fuse and positive solar adapter lead to positive solar panel lead. Connect the negative solar adapter cable to the negative solar cable. do not let exposed wires touch! ⚡

Didn’t I say it would take 20 seconds?

until the last 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 the solar panel to the charge controller!

Connect the solar negative 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.

As before with the battery, the charge controller should turn on or somehow indicate that the solar panel is properly connected.

At this point, check your charge controller’s manual to see if you need to program it. you may need to provide battery type, voltage, or other details.

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

and voila!

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

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

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

Tip: If you’d like some ideas on how to add to this setup, check out my tutorial on creating your first solar panel system.

frequently asked questions about wiring the solar panel to the charge controller

1. why do i need solar adapter cables?

Your solar panel cables will likely come with pre-installed mc4 connectors. mc4 connectors are great for connecting two solar PV cables together…

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

solar adapter cables have an mc4 connector on one end and are stripped on 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 connectors that match your solar panel cables.

if you can’t find any, you may need to make your own by cutting two lengths of solar PV cable, stripping both ends, and crimping the corresponding connectors.

3. Why doesn’t my charge controller turn on/turn on when I connect my solar panel?

your panel probably just needs a little sun!

place it outdoors in direct sunlight. your charge controller should light up or indicate in some way that the panel is properly connected and the battery is charging.

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