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The inverter and charge controllers are vital components in an off grid solar system, each with specific roles to play. So should you connect an inverter to a charge controller? What will happen if you do? This guide will explain what you need to know.
Charge controllers should be connected to the battery, not the inverter. An inverter should be connected to the battery terminal after the charge controller, battery and solar panels are already wired together. Connecting an inverter to a charge controller could render both inoperable.
How to Connect a Charge Controller and Inverter to a Solar Panel
Connecting the inverter to the charge controller could result in irreparable damage to both, so make sure to wire each solar system in the proper sequence.
- Connect the charge controller to the battery. Do this before you connect the solar panels.
- Connect the male solar panel MC4 connector into the adapter kit female connector. Repeat this with the female solar panel MC4 connector, but connect it with the male connector adapter.
- Link the charge controller negative terminal to the negative solar panel line. Repeat with the positive charge controller terminal and the positive solar panel line.
- Connect the negative inverter port to the negative battery terminal. Repeat this with the positive inverter port and the positive battery terminal.
Make sure the inverter and charge controller size is appropriate for the battery. If you bought a solar panel kit the exact sizes will be specified.
The steps above are applicable to virtually all solar panel systems that use these components. However you should still refer to the manual for specific instructions that may pertain to your system.
Difference between a Charge Controller and Inverter
If you want to get the most out of your solar system, understanding the differences and functions of inverters and charge controllers are a must.
- Solar panels produce DC power, and an inverter transforms this DC power into AC power that household appliances and tools can use.
- An inverter charger does the same thing but it can also convert DC into AC power to recharge batteries.
- A hybrid inverter allows grid power, generators and other types of AC power sources to recharge batteries.
An inverter can be used in a grid tied or off the grid solar system. There are two basic types, pure sine and modified sine wave. Pure sine generates cleaner power but costs more.
A charge controller regulates the power going into the battery. Its task is to prevent overheating, overcharging and overloading. Charge controllers also charge the battery using the power produced by the PV modules.
There are two types of charge controllers, PWM and MPPT. MPPT controllers do a more effective job in optimizing solar power and provides more configuration options. MPPT controllers are more expensive though, and PWM remain the most widely used.
Why inverters Must Never be Connected to Charge Controllers
Inverters and charge controllers perform very specific functions in a PV system. They are designed to work together along with batteries and solar panels to produce power.
As explained above, inverters are devices used to make solar power usable for common household appliances and any device that runs on AC power. Some of them can function as a charger too, though not al inverters have that feature.
A charge controller is concerned with the power going into the battery. Specifically the controller will ensure the battery is ready to supply the inverter with power. Without a charge controller, there are no safeguards to protect the battery from being overcharged.
An overcharged / overloaded battery is going to cause all kinds of problems for the solar system and any loads connected to it. Problems can also occur if the inverter and charge controller are not connected properly, hence the need to follow the installation and wiring directions to the letter.
Can I Use a Charge Controller without an Inverter?
Almost all solar power system setups with storage require a charge controller and inverter. It is possible to use a charge controller without an inverter, but the solar system will only be able to run DC powered devices.
To recap, a solar panel produces energy and the extra power is stored in a battery bank. The charge controller ensures the battery is properly charged.
When there is enough power in the battery to run appliances, the inverter converts the stored energy – which is DC – into AC so these appliances can run.
Without an inverter, no AC powered appliance or device can run. You can still connect devices that run on DC power though.
For most solar power system setups this is impractical. The whole purpose of going solar is to run household appliances on renewable energy and no longer depend on the grid.
So while it is technically possible to use a charge controller without an inverter, there are few instances where you should.
Can I Use an Inverter without a Charge Controller?
Yes, there are many inverters that do not require a charge controller. Solar powered homes connected to the grid do not require batteries and therefore do not need charge controllers.
In a system that does not use battery storage – such as a grid tied home – an inverter charger will direct the solar power to your house and use the energy.
Any solar power generated that does not get used reverts back to the grid where you can access it at any time. This is how most solar powered homes in the US are set up so there is no need for batteries or charge controllers.
There are many reasons why many prefer this setup:
- You have access to the electrical grid in case of insufficient solar power.
- It eliminates the need to buy batteries, which can be expensive.
- Installation is cheaper.
- Costs less than an off grid setup.
The one disadvantage with a grid tied solar system is you will not be able to use it during a power outage. When the grid power goes out, all connected PV systems are shut down to prevent solar power electrocution risk for utility workers.
If you want to have solar power during a blackout, a battery bank has to be installed. And if you are going to use batteries, a charge controller will be necessary.
Can a Solar Panel Work without an Inverter?
Yes, solar panels will run fine without an inverter. If you are only going to run DC powered devices on solar, there is no reason to use an inverter.
Any device that runs on batteries is DC powered and can be connected directly to solar power without using an inverter. You can connect a DC load directly to solar panels as there is no need to convert to AC.
Digital cameras, drones, TV remote, cell phones, laptops, wall clocks and electric vehicles are some examples. Flat screen TVs use DC power though this is converted into AC if connected to an AC power source.
Can a Solar Panel Work without a Charge Controller?
A solar panel can operate without a charge controller or batteries. As explained earlier, a grid tied PV system does not need battery storage because excess solar power goes into the grid.
We did point out the disadvantage of this setup though, the lack of solar power during a power outage. For an off grid solar system, a charge controller and batteries are essential.
You can run an off the grid PV system without a charge controller or batteries. But power will only be available as long as there is sunlight. Once the sun goes down the panels can no longer supply any power.
Unless you have a generator your system will be powerless. If you have a battery bank, you can charge it during the day so there is power available at night. With a charge controller you are also assured only the safe amount of power is going into the system.
Knowing how to set up a basic solar system is essential for anyone who wants to use renewable energy. Even if you prefer a professional installer do it, knowing the proper way to configure inverters and charge controllers can help if you need to troubleshoot.