How To Select a Solar Charge Controller?

If you have a solar device installed in your home, be it a solar panel, light, or any other device, it may be a good idea to get your hands on a decent solar charge controller as well.

A solar charger prevents the solar product’s battery from threats such as overcharge, overheating, and low voltage. It is a handy unit and is a good investment. A solar charger can be used for different purposes. It can be used to charge solar electric fence. That is why, in this writeup, we will share techniques on how to select a solar charge controller so that you can choose a model that best fits your needs.

But first, let us start with the basics about the Solar Charge Controller.

What is a Solar Charge Controller?

In simple terms, a solar charge controller is a device that regulates the amount of power flowing in and out from a solar battery. You can use a solar charge controller with any power source such as PV, wind fuel, hydro, and others.

Functions of a Solar Charge Controller

There are mainly three functions of a solar charge controller:

1. Preventing Overcharge

The solar charge controller allows any amount of energy flow when there is little battery charge remaining. After reaching a certain voltage, the unit starts regulating the energy. This function helps prevent overcharging of the battery.

2. Blocks Reverse Current

During the night, the solar panels have low voltage due to which the power flows out from the battery. A solar charge controller prevents this backflow, thus lengthening the battery life.

3. Load Control

The unit automatically turns the load on or off received from a D.C. outlet.

What To Consider Before Purchasing a Solar Charge Controller?


Now that you know the basics about a Solar Charge Controller, we will take you through seven essential things that you should consider before buying a unit for yourself.

1. Controller’s Type

There are mainly two types of Solar Charge controllers available on the market – Pulse Width Modulated Charge Controller (PWM) and Maximum PowerPoint Tracking Charge Controllers (MPPT).

If you want a controller for small PV systems,  then the PWN charge controller works great. Likewise, if you want a charger for residential solar units that require more efficiency, then go for an MPPT charger.

2. Battery Voltage

Figure out the battery voltage of your system. Most devices use a battery of  12 volts, 24 volts, or 48 volts. Buying a controller that supports the device lesser than your system’s battery voltage is just a waste of money. So always read the voltage limit of the controller and select the one that can supply power to your desired unit.

3. Maximum Current Output

The solar panels can send a diverse range of current to the solar charge controller. Thus, the controller should be able to process the different currents sent by those panels.

Also, the controller should manage the current that it sends to the battery. High current flow can damage the battery. Likewise, a low current may affect the devices plugged into the system.

4. Maximum Input Voltage

Every solar charge controller comes with an input voltage limit. Make sure the limit is always more than the highest voltage provided by the solar panel in the system. Sometimes, you may even decide to connect multiple solar panels to maximize power output.

We recommend you purchase a solar charge converter with a higher input voltage. A high input voltage charge converter allows you to connect multiple solar panels of higher voltage to the charger without damaging the battery pack.

5. Budget

If you are budget conscious and your energy needs are not that high, then choose a PWM controller rather than an MPPT controller. PWM is cheaper than MPPT and is suitable for low voltage systems.

6. Additional Features

Apart from all the technical details we mentioned above, you also need to look for additional features such as safety, display system, and temperature compensation. The solar charge controller should be able to protect your system from short-circuit, overcharging, discharge, and reverse charging.

If the controller features an LED display, then it will be easier for you to read the charge, voltage input, and other important notifications. Temperature compensation decreases the amount of voltage reaching the battery, which will prevent the battery from overheating.

7. Warranty

Finally, make sure to check the manufacturer’s warranty on the charge controller. Select the one with at least a one-year warranty. The warranty will ensure that if anything goes wrong with the unit, you have the option to get a free repair or return it. Find out the terms and conditions that you must abide by to enjoy the warranty.

FAQs

A solar charge controller has a simple working mechanism.

You need only connect it between the solar panel and the battery pack. A solar charge controller regulates the power transferred from the solar panel(s) to the battery. Depending on the need, the controller fluctuates the charge that it sends out to the battery. This process will extend battery life as well as increase the efficiency of your solar unit by up to 50%

In general, yes, because the MPPT chargers can handle higher voltage and do not waste any power during operation. However, if you want to regulate a smaller system, then we always recommend you to select the PWM controller, as they are much more cost-effective and works best with low-voltage.

No. The solar charge controllers are designed specifically for solar energy systems only, and you should not connect it with other renewable energy systems. If you want to regulate systems other than solar devices, then you need to search for charge controllers designed particularly for such systems.

If you cannot decide which controller you should purchase, then you need to figure out some things. First, read the voltage and current of your solar panel(s). Then add 25% of their value to both of the readings. Now you need to search for a solar charge controller that has its voltage and current readings higher than the amount you calculate.

This will makes sure the controller can handle any surge in the voltage and current produced by the solar panel.

Finals Words

Finding a decent solar charge maintainer is not that difficult if you know the correct technique. In this writeup, we have mentioned the seven important things that you should look for in any solar charge controller. Watch out for these factors, and we ensure that you can find a solar charge controller that best fits your energy needs.