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Solar Charge Controllers are electronic devices used to control the solar charge passing into the battery bank from the system. It is deployed for solar power generation.
The primary function of these controllers includes preventing the deep-cycle batteries from overcharging during the daytime.
Also, a solar controller prevents power drainage from the batteries during the night. It means that solar charge controllers do not let the power pass back to the solar panels.
A solar controller essentially manages the passage of voltage and current arriving from the solar panels to the battery. Notably, some solar charge controllers are available with additional attributes such as load control. Yet, regulating the power is their principal function.
Key features of Solar Charge Controllers
- Multi-level charging of battery bank: A solar controller modulates the amount of power coming to the batteries. It’s important to ensure the healthy functioning of batteries.
- Protects reverse flow of power: It obstructs the power drain from batteries back to the solar panels overnight. It’s essentially important when no power is passed from the solar panels to the batteries.
- Turns off connection during low voltage: It turns off the connected load whenever the battery is low. When the battery gets charged, the controller turns on the load again.
- Manages the lighting: Solar charge controllers turn on and off the lights connected to it as per the time of the day (dusk and dawn). The users can configure such settings for a few hours or the whole night.
- Display monitor: Depending on the model, a solar controller can display the voltage of a battery bank, status of charge, amps arriving from the panel, etc.
Why use Solar Charge Controllers?
A solar controller is considered essential for a solar system to function productively. You may not desire to sacrifice the quality of operations anyway to save some money.
You have to ensure that the batteries can safely handle the amps generated and sent by the solar panels. Solar charge controllers are significant for this purpose.
Overcharging and high voltage can:
- Lessen the performance and life of the battery.
- Pose a safety risk.
A solar controller deals with both these issues: it prevents overcharging and offers protection against high voltage. Besides, it also prevents battery draining (or deep discharging) to ensure long battery life.
Types of Solar Charge Controllers
There are two major categories of solar charge controllers:
- MPPT Solar Charge Controller
- PWM Solar Charge Controller
MPPT Solar Charge Controller
An MPPT (Maximum Power Point Tracking) solar charge controller measures the VMP (Voltage at maximum power) input voltage of the panel and transforms the PV voltage to correspond to the battery voltage.
It reduces the high voltage arriving from the solar panel to match the lower voltage of the battery. As the voltage is brought down corresponding to the battery bank, the current rises.
PWM Solar Charge Controller
A PWM (Pulse Width Modulation) solar charge controller is used to connect the solar system straight with the battery bank. To charge a 12V battery, you will require a 12V solar panel.
If we use a 24V solar panel with a 12V battery, the PWM solar controller will not reap the additional energy produced after 12V. It will reap 12V only.
MPPT v/s PWM Solar Charge Controllers
| Basis of Difference | PWM Solar Charge Controller | MPPT Solar Charge Controller |
| Productivity | The maximum productivity of PWM controllers is up to 68-70%. It is relatively less productive. | The maximum productivity of the MPPT controller is around 96%. It is highly productive. |
| Size | It is smaller in size. The maximum capacity is 60 amps. | It is larger as it is specially designed for bigger solar panels in a productive approach. |
| Market Existence | PWM controllers are sold in the market for a long time. Hence, these are tried and tested by people. | An MPPT controller is a relatively new technology. Hence, it is currently trending in the market. |
| Price | The PWM solar charge controller price is half as compared to the MPPT Controller. | MPPT solar controller price is comparatively higher. Though, it is a one-time investment. |
| Limitations | One cannot use it with a large number of solar panels (>10 panels) | It is highly efficient, the only limitation of an MPPT controller is its high cost. |
Price of Solar Charge Controllers
Many brands in India offer solar charge controllers. The range of their power rating varies from 10 amps to 60 amps with PWM and MPPT technology.
The solar charge controller price is based on several aspects, including their power rating, technology or category, and brand.
Here is a general (average) solar controller price range:
- 12V Solar Charge Controller (10A-40A) = Rs. 1,705 – Rs. 4,100
- 24V Solar Charge Controller (10A-40A) = Rs. 2,460 – Rs. 7,900
- 36V Solar Charge Controller (10A-40A) = Rs. 4,095 – Rs. 10,250
- 48V Solar Charge Controller (10A-60A) = Rs. 6,150 – Rs. 30,050
Please Note: The charges vary from seller to seller. Always compare the prices with different sellers before making a purchase.
Examples of the Solar charge controllers
Here are some examples of Solar Charge controllers:
- 6 amp, 12 volt Luminous solar charge controllers
- Microtek Mtek 1012 SMU complete solar management unit
- Sukam solarcon PV charge controller (20 amps, 12-24V)
- 30 amps, 12V-24V Smarten MPPT Solar Management Unit Controller
- Sukam MPPT solar charge controller (40 amps, 48 volts)
- SURYA PWM Solar charge controller
- Microsol PWM Solar charge controller (12V, 60A)
- UTL MPPT solar charge controller
Application of solar charge controllers
Over the past decade, generating electricity from solar energy is gaining high popularity. As compared to conventional sources of energy, solar panels generate completely pollution-free energy. Also, they don’t demand very expensive maintenance.
Solar charge controllers are used amid the solar arrays or systems for ensuring the efficiency of the system. Mainly, solar charge controllers find their application in off-grid solar-plus-storage systems.
Conclusion
A solar controller is a device that regulates the voltage & current to keep a check on the overcharging of batteries. Typically, most 12-volt solar panels generate about 16 to 18 volts of solar charge.
If there is no charge management, the batteries will get damaged due to overcharging. Solar charge controllers support the solar array; thereby, increasing productivity.
So, those thinking of buying a solar controller should go through our comprehensive review before making an investment decision.
FAQs
Q1. Do we have to compulsorily use a solar controller in an off-grid solar array?
It is greatly suggested to use a solar charge controller in an off-grid solar system to protect the batteries from damage.
In its absence, battery life will scale down due to overcharging or deep discharging. There remains a risk that the connected appliances may fuse due to the unregulated flow of high voltage from solar panels.
Q2. How to choose solar charge controllers for the solar panels as per the rating?
You will find the current and voltage information on the sticker on the backside of solar panels.
The rating of your solar controller should be 20% greater than the maximum current output by the solar panels.
Q3. Is a charge controller required for every solar panel?
Solar charge controllers are not essential for all solar panel systems. They are required for large off-grid solar arrays. In small solar arrays, a solar inverter will do the job of increasing your battery’s life.
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