Eternal Inverter 
Overview of MPPT solar charge controller
MPPT (Maximum Power Point Tracking) solar charge controller is an advanced charging management device for solar panels. Its main function is to ensure that solar panels operate at the best power point (maximum power output) by adjusting the working voltage and current of solar panels, thus improving the overall system efficiency
Working principle: MPPT solar charge controller monitors the voltage and current of solar panel in real time, and calculates the maximum power point by using algorithm. The output power of solar panels is usually affected by temperature, irradiation angle and weather changes, and the maximum power point (MPP) is not fixed. Therefore, the MPPT solar charge controller needs to constantly adjust the voltage and current to ensure that the battery always works near the maximum power point. The specific steps are as follows:
- Collecting voltage and current data of solar panels: monitoring the working state of solar panels in real time
Calculate the maximum power point: calculate the maximum power point of the solar panel through an algorithm
Adjusting the working voltage: the controller adjusts the working voltage of the battery panel to make it close to the maximum power point
Optimize the charging process: at the maximum power point, the controller converts the excess energy into the charging current suitable for the battery
Common battery types
- Lead-acid batteries: open lead-acid batteries, sealed lead-acid batteries, gel-absorbing lead-acid batteries and colloidal lead-acid batteries
Lithium battery: lithium iron phosphate battery and ternary lithium battery
Sodium-Sulfur Battery
Nickel-Metal Hydride, NiMH Battery
Lead-Carbon Battery
Adaptability of MPPT solar charge controller to battery type
- Lead-acid battery: MPPT solar charge controller usually supports the use with various lead-acid batteries (such as open lead acid, sealed lead acid, AGM, colloid, etc.). The charging process of lead-acid batteries usually includes absorption charging, floating charging and balanced charging stages. The MPPT solar charge controller can automatically adjust the charging voltage according to the specific needs of the battery to ensure that the battery can obtain appropriate voltage and current at different charging stages
Lithium battery: Because the charging voltage and current of lithium battery are strict, MPPT solar charge controller must support special charging curve of lithium battery. Lithium batteries usually have higher charging efficiency and longer service life, but the charging voltage and current need to be accurately controlled to avoid overcharge or over-discharge
Sodium-sulfur battery: The working voltage and charging current of sodium-sulfur battery are high, so the MPPT solar charge controller must support higher charging voltage and current and have strong temperature management ability. Sodium-sulfur battery is very sensitive to temperature and needs to be charged in a specific temperature range
Ni-MH battery: The charging requirements of Ni-MH battery are similar to those of lead-acid battery, but the requirements for charging current are more stringent. When MPPT solar charge controller supports Ni-MH battery, it is usually necessary to adjust the charging voltage and current of the battery to avoid overcharge or damage
Ni-MH battery: The charging requirements of Ni-MH battery are similar to those of lead-acid battery, but the requirements for charging current are more stringent. When MPPT solar charge controller supports Ni-MH battery, it is usually necessary to adjust the charging voltage and current of the battery to avoid overcharge or damage
How to choose the right battery and MPPT solar charge controller?
In order to consider whether the appropriate matching is the key to ensure the efficient and stable operation of the system, please refer to the following brief selection guide:
Battery type:
Lead-acid battery: low cost, suitable for small systems, but it needs regular maintenance. Suitable for low-budget users
Lithium battery: It has high charging efficiency and long service life, but it is more expensive. Suitable for long-term and efficient systems
Ni-MH battery: environmental protection but low energy density, suitable for small systems
MPPT solar charge controller type:
PWM solar charge controller: Suitable for small systems, with low cost but low efficiency
MPPT solar charge controller: high efficiency, suitable for large-scale systems, able to maximize the use of solar energy, and supporting a variety of battery types
Matching elements:
Voltage matching: Ensure that the voltage of the battery, the battery panel and the controller is consistent (for example, 12V, 24V or 48V)
Charging current: The controller must be able to provide enough charging current to meet the demand of battery capacity
Charging curve: different battery types have different charging methods, so as to ensure that the controller supports the corresponding charging mode
Application requirements:
Select the appropriate battery and MPPT solar charge controller according to the scale and use environment of the system
Use and maintenance:
Lithium batteries need almost no maintenance, while lead-acid batteries need regular inspection. Choosing an efficient solar charge controller (such as MPPT) can prolong battery life and reduce maintenance frequency
Choosing the appropriate battery and MPPT solar charge controller is very important for the efficiency and battery life of solar energy system. MPPT solar charge controller can efficiently cooperate with lead-acid batteries, lithium batteries and other battery types to ensure the optimization of charging process.
Knowing the battery charging demand and selecting the matching controller can not only improve the system efficiency, but also prolong the battery life and reduce the maintenance cost. Make sure to choose the right battery and controller according to your needs to help your solar system run stably and efficiently！