There are 4 main parts to a solar panel system – solar panel (duhh), battery, inverter, and charge controller.
If it’s your first time installing this equipment then you might be unsure of where to connect everything together.
One question I get asked a lot is ‘Can I connect an inverter to a charge controller?’
Well, the answer is that you probably shouldn’t!
Of course, there’s always an exception to the rule and I’ve seen a lot of misguided advice out there.
But never fear.
Let’s go through the answers in simple English, plus answer the other relevant questions on the subject.
By the end of this article, you’ll know the difference between inverters and charge controllers, plus how you need to wire them up.
Should You Connect an Inverter to Charge Controller or Battery?
It is a bad idea to wire an inverter to a charge controller, particularly if you are drawing high amperage. This is because a charge controller is built to work with fewer amps compared to what your inverter can draw. You should connect your inverter directly to the battery.
A charge controller’s main role is to efficiently charge your battery from the solar panel. Solar panels will have a limit as to how much energy they can produce which is then stored in the battery. An inverter can then use this battery energy to run appliances at a higher power than the inverter.
For example, you could charge batteries with a 100 watt solar panel with a current of 8 amps using a 20 amp charge controller. Then you could use this charged battery to draw 500 watts with an inverter which would result in 40 amps in the circuit. That’s double the amps your charge controller is designed for… the system would blow a fuse or even worse start to melt!
By connecting your inverter directly to the battery you bypass the charge control and avoid this problem.
Some people still like to wire inverters to the charge controller if they know they are only pulling a small current, but why risk it?
How to Connect an Inverter and Charge Controller
Now you know it’s best to connect inverters and charge controllers separately here are the steps to hooking up your system:
- Connect the charge controller to the battery with the red wire to the red battery terminal (positive to positive) and the black wire to the black terminal (negative to negative). Always do this before connecting the solar panel.
- Connect the inverter to the battery with the red wire to the red battery terminal (positive to positive) and the black wire to the black terminal (negative to negative).
- Now you can wire the solar panel to the charge controller, once again red to red and black to black.
N.B. Always ensure all your equipment is rated for the same voltage such as 12V or 24V. For example, don’t try to use a 12V inverter with a 24V battery, etc.
Here’s a helpful inverter, charge controller, solar panel, and battery wiring diagram to help you visualize it:
Inverter vs Charge Controller: What’s the Difference?
There is a very big difference between an inverter and a charge controller.
To be honest, they perform opposite tasks.
A solar charge controller helps to efficiently charge a battery and protect it from issues like overcharging. It connects between the solar panel and battery to monitor the energy moving from the solar panel into the battery.
A power inverter enables you to convert the battery’s DC electricity into AC electricity which is needed to run most appliances and electronics. It connects to the battery and allows you to plug appliances into it, just like a wall plug at home. Without an inverter, you can draw power from your battery or solar panel.
To sum up: A charge controller charges a battery and an inverter uses energy in a battery.
Do You Need a Charge Controller if You Have an Inverter Charger?
If you’ve got an inverter charger then you might wonder if you even need a solar charge controller…
Well, it depends on your inverter charger.
Most inverter chargers are designed with a charging function to be used with AC input such as the main grid or generator. It works by converting the AC into DC electricity that can be stored in a battery. In this case, you can not use it to charge with a solar panel and need a charge controller.
You can also get inverter chargers with the ability to do everything including charge from solar panels. You should look for inverter chargers with MPPT solar capabilities. In this case, you would not need a solar charger as it is built into your inverter.
Can You Connect an Inverter Directly to a Solar Panel?
It is possible to connect an off-grid inverter directly to a solar panel but you shouldn’t.
You will not get reliable performance as the power and voltage from the solar panel will vary depending on external factors such as sunlight. You won’t be able to run AC appliances properly although you might be able to charge a phone or tablet.
Grid-tie inverters, which are designed for home use and tied into the mains grid, can be connected to solar panels without needing to connect via a battery. This is because when power levels drop the electricity supply switches to draw from the mains grid.
Do You Need Both an Inverter and a Charge Controller?
Yes, an off-grid solar panel system requires both an inverter and a charge controller. Without these components, you won’t get reliable performance. Not using a solar charge controller risks overcharging and damaging your battery. Without a power inverter, you can’t draw power from your battery.
Final Words on Connecting an Inverter to a Charge Controller
If you’ve read this far you should now understand whether you can connect an inverter to a charge controller.
The simple answer is don’t do it. You are much better off hooking up your inverter to your battery. Then you won’t be limited in the amount of current you can draw.
Connecting an inverter to a charge controller means you risk drawing more amps with your inverter than the charge controller can handle.
If you want to reduce the number of components in your system, then you could always try an inverter charger with MPPT solar charging capabilities.
