A Solar Charge Controller Is Essential For Any Solar Power System
If you are planning a solar power system that uses batteries, a charge controller is essential.
The controller solar charge controller 12v connects your PV array to the battery, and it controls how much power is being gathered by the battery.
Electricity flows from the high voltage of the solar panels to the lower-voltage battery. Without a charge controller, this energy could flow back into the panels and cause damage.
What is a solar charge controller?
The charge controller is an essential part of any solar energy system that uses batteries to store power. It monitors the voltage of your solar panels and battery and adjusts the flow of electricity to prevent overcharging. It can also monitor weather conditions and make changes accordingly, increasing efficiency and preventing damage from the elements.
It also stops electricity from flowing back into the solar panel when there’s no sun, which could otherwise shorten their lifespan. This is because electricity flows from high to low voltage, and without the charge controller in place, this power would keep draining your battery at night.
There are two main types of charge controllers: PWM and MPPT. MPPT, which stands for Maximum Power Point Tracker, is more advanced than PWM controllers and allows you to get the most out of your high voltage grid tie solar panels. It works by measuring the operating voltage of your solar panel (Vmp) and then down-converting it to match your battery bank’s voltage, allowing you to use larger panels wired in series than you might otherwise be able to.
PWM solar charge controllers are cheaper, but they don’t offer as much flexibility as the more advanced MPPT models. They work by connecting directly to your solar panel and battery, pulling the output of the array down to the same voltage as the batteries and keeping this constant throughout bulk charging.
MPPT Charge Controllers
MPPT controllers are more advanced than PWM controllers and provide a higher level of energy optimization. They utilize a smart DC-to-DC converter that allows the solar panel array to operate at a higher voltage than battery voltage (known as the maximum power point). This increases the power that can be extracted from the solar panels by up to 30%.
A battery’s charge (absorption) voltage is usually 3V to 8V lower than the optimum panel operating voltage (Vmp). The Vmp of a solar panel can vary throughout the day based on the varying amount of sunlight (irradiance) that reaches it. An MPPT solar charge controller can find the optimum ratio of current and Solar Inverter voltage that produces the most power for the system, regardless of the time of day or weather conditions.
PWM solar charge controllers are great for small DIY systems with a couple of low-voltage solar panels and a tiny battery. They’re simpler than an MPPT controller and tend to be less expensive.
However, an MPPT solar charge controller is an excellent choice for larger home solar-plus-storage systems, especially in cloudy environments where efficiency matters most. The more energy you can generate and store with your solar energy system, the faster you’ll see a return on investment. Shop EcoFlow today for solar-plus-storage systems that include a high-efficiency MPPT charge controller to help you reach your ROI more quickly.
Choosing the Right Charge Controller
The simplest and least expensive automatic way to control the flow of power between solar panels and a battery is a PWM charge controller. These devices send out “pulses” of current over a hundred times a second to reduce the battery’s voltage while charging. They are best suited to small off-grid solar systems that don’t need a lot of capacity, such as a solar lighting system for camping or basic USB/cell phone chargers.
The first step in selecting a charge controller is to determine your battery’s rated voltage and find one that matches or exceeds it. The next step is to identify how many amps the solar panels are rated for and select one that can handle at least that amount plus 25%. This 25% cushion is a safety feature that ensures the controller can prevent your solar array from overcharging the battery and shorting out your solar panel output.
Another important factor to consider when sizing your charge controller is the voltage regulation setpoint (VR). This is the minimum level at which the charge controller will disconnect the battery from the PV source and regulate the power supply. Choosing a VR that is too low will cause your battery to be repeatedly connected and disconnected, which can damage the life of your batteries. More advanced MPPT solar charge controllers come with display screens that allow you to monitor the voltage and state of charge of your batteries.