how to select solar charge controller

How To Select Solar Charge Controller

The most essential function of all solar charge controllers is to properly charge the batteries while also making sure they are maintained for as long as possible. There are two different types of charge controllers:

  • PWM also called Pulse width modulation
  • Maximum power point tracking (MPPT)

The distinction between these two types of controllers is that the PWM is not as efficient at converting direct current to alternating current. The most popular right now is the MPPT, which can give you up to 30% more power than a PWM controller. The MPPTs allow strings of panels in series for higher voltages and putting the amperage lower and reducing wire size, especially for long-wire runs to solar arrays.     

Choosing the right charge controller is a simple process with just a few steps. To ensure that you get the correct controller for the task, follow these steps. The greatest thing you can do is to utilize the manufacturer’s sizing tools that are accessible on their websites. Alternatively, you might give the manufacturer a call and ask them for assistance in selecting the best charge controller.

If you must perform some rapid calculations, the following information will be required to calculate the controller’s amperage by hand: 

  • The wattage of the solar array
  • The battery bank voltage (12, 24, or 48). Because inverters are available in these voltages, they use standard bank voltages.
  • Now Ohm’s Law comes into the play: Amps x Volts = Watts

For Example, These are the most basic factory-built systems. They have a 300-watt, 1500-watt, or 3000-watt array and a 48-volt battery bank. The system requires an inverter rated at 62.5 amps (that is 1,250 watts in “w”). The majority of inverters available are 60, 80, or 96 amps; therefore you would choose one with the next higher rating. In this instance, it is the 80 amp controller.

How Does Solar Charge Controller Works?

how to select solar charge controller

Charges are prevented by a charge controller from flowing into your battery when it is damaged, leaking, or has a low charge. In most charge controllers, a charge current goes through a semiconductor, which acts as a valve to regulate the flow of electricity. When your batteries reach a particular voltage, charge controllers lower the amount of energy supplied to them in order to protect them against overcharging. Because overcharging can be particularly harmful to the battery itself, charge controllers are especially important.

They also have various uses in addition to charging the battery. Low voltage disconnects, overload protection, and the blocking of reverse currents are all features of charge controllers.

Overload protection: Overload protection is provided by charge controllers. Your system current might overheat if the current flowing into your batteries is greater than the circuit can handle. Overheating or even fires may result as a consequence of this. Charge controllers dose not allow these overloads from happening. We recommend additional safety precautions in large systems, such as circuit breakers or fuses.

Low voltage disconnects: When the voltage dips lower than an acceptable level, this device disconnects non-critical loads from the battery automatically. It will reconnect to the battery as soon after it has been charged as possible. This may prevent an over-discharge.

Block Reverse Currents: Solar panels move electricity in one direction. Solar panels may naturally reverse some of the currents throughout the night. This can cause a minor discharge from the battery as a result of this natural flow. Charge controllers serve as valves to prevent this from happening by functioning like switches.

What Factors Should You Consider When Selecting A Charge Controller?

When purchasing a charge controller, the following questions should be considered:

  • Your budget
  • The lifespan of the technology
  • Keep in mind that certain charge controllers function better in colder environments.
  • How many solar panels do you have and how high are your energy requirements are
  • Size, number, and type of batteries you are using in your system

When you are deciding which type of charge controller to use, your choice is limited by a number of restrictions. However, there is a straightforward procedure for determining which charge controller is appropriate for your application.

Do You Always Require A Solar Charge Controller?

Yes. Small 1 to 5-watt panels that may be used to charge a phone or power a single light do not need a charge controller. If the output of a panel is 2 watts or less for each 50 battery amp-hours, you do not require a charge controller. You must have one of the output greater than 2 watts per 50 battery amp-hours.

Solar charge controllers are crucial in solar power systems, ensuring that they are safe and efficient. You can not just hook your solar panels to a battery and expect them to work. Solar panels generate more electricity than their rated voltage suggests. For example, a 12v solar panel may produce up to 19 volts.

While a 12v battery can withstand up to 14 or 15 volts when charging, it is extremely dangerous and may result from overcharging if put on a 19-volt battery. Solar charge controllers are not an optional component that makes solar power charging more efficient. They are an absolute must-have that enables solar power battery charging to happen.

Can You Use More Than One Charge Controller?

You may use several charge controllers with one battery bank if a single charge controller is insufficient to manage the output of your solar panel array. In fact, for MPPT charge controllers, connecting your system in this manner might be the ideal method because maximum power points vary across arrays. Connecting two controllers can improve overall power output by optimizing the total power output.

Individuals who install solar power systems frequently go on to expand them. It is not unusual for the expansion capacity to far exceed the capabilities of the existing charge controller.

However, if you have more than one charge controller, we do recommend using the same type. So if you only have one MPPT charge controller, all of these charge controllers should be MPPTs. You will also want to double-check that all of your controllers are set to the same battery setting input.

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