A solar charge controller has various settings that need to be altered for it to function properly, such as voltage & ampere settings. Today you will get to know about solar charge controller settings along with solar charge controller voltage settings.
Solar Charge Controller
The amount of power generated from the solar panel travels to the inverter batteries. This power needs to be maintained and regulated. A solar charge controller is used for this purpose. It sends short energy pulses to the battery. The average output produced by an MPPT solar charge controller can be 42 volts. You will require additional batteries to produce higher voltages. Here is the catch: to prevent your batteries from damage, you need to choose the right solar charge controller.
Solar Charge Controller Settings
Just installing a charge controller won’t solve all your problems. There are different settings that need to be checked and manually adjusted. Different types of batteries like Lithium Iron Phosphate (LIPO), lithium, iron phosphate, lead-acid, and Absorbent Glass Mat (AGM) batteries have different settings. However, there are only two types of charge controllers.
1. MPPT controller or maximum power-point tracking controller
2. PWM controller or pulse width modulation controller
Before starting to set up the solar charge controller, you need to understand its functioning of it. Here are the points that you need to keep a note of while installing and setting up the solar charge controller.
Once the battery is fully charged, the battery will not hold more solar energy in comparison to the chemical content.
- If the battery is charged high, it can result in the development of heat and gas inside the battery.
- Electrolytes inside the battery began to expand. This further led to the development of bubbles.
- This chemical process leads to the generation of hydrogen gas, which is explosive.
- An overcharged battery will decrease the capacity and increase the aging process of the battery.
1. Battery Floating Charging Voltage
The voltage at which a battery is maintained once it is fully charged is known as the battery floating charging voltage. This voltage maintains the capacity of the battery by self-discharging it. The typical voltage for a 12V system is 13.7V and for a 24 V system, it is 27.4V. 58.4V is the voltage for a 48V system.
2. Battery Over-Discharging Protection Voltage
It is also known as under voltage cutoff voltage and its value should also be in accordance with the battery type. In solar charge controller settings, the voltage value range for a 12V system is 10.8V to 11.4V. For a 24V system, it is 21.6V to 22.8V, and 43.2V to 45.6V for a 48 V system. So, the typical values are 11.1 V, 22.2 V, and 44.4 V.
3. Battery Overcharging Protection Voltage
This voltage value should be set as per the battery type. This voltage is also termed a fully charged cutoff voltage or over-voltage cutoff voltage. This voltage value for a 12-volt system ranges between 14.1 V and 14.5 V. For a 24-volt system, it is 28.2V to 29V and for a 48V system, it is 56.4V to 58V. So overall, the typical value for the voltage is 14.4V, 28.8V, and 57.6V.
4. Charge Controller Capacity
It is the maximum number of amperes that your solar charge controller can handle. It is the parameter on the basis of which a solar charge controller is rated. It can be 10A, 20A, 30A, 40A, 50A, 60A, 80A, or 100A.
5. Maximum Charging Current
It is the maximum output current of the solar panels or solar arrays. It is the output that you receive from the batteries.
6. System Voltage
It is also known as the Rated Operational Voltage of your solar power system which refers to the battery bank voltage (direct current operational voltage). Usually, the value is 12V, 24V, or 48V. However, a medium-scale or a large-scale charge controller system has voltage values of 110V and 220V.
Also See: What Size Charge Controller for 200W Solar Panels?
Solar Charge Controller Voltage Settings
These are the most critical settings that need to be done carefully for the better functioning of the solar charge controller. A solar charge controller is capable of handling a variety of battery voltages ranging from 12 volts to 72 volts. As per the basic solar charge controller settings, it is capable of accommodating a maximum input voltage of 12 volts or 24 volts.
You need to set the voltage and current parameters before you start using the charge controller. This can be done by adjusting the voltage settings. Here is the list mentioning the most critical voltage settings for the solar charge controller.
- Absorption Duration: (Adaptive/Fixed)
- Absorption Voltage: 14.60 volts
- Automatic Equalization: (Disabled / Equalize every X Days) Disabled
- Equalization Current Percentage: 25%
- Equalization Duration: 4 hours
- Equalization stop mode: (Fixed Time / Automatic on Voltage) Fixed time
- Equalization Voltage: 14.40 volts
- Float Voltage: 13.50 volts
- Low-Temperature Cutoff (optional): Disabled
- Maximum Absorption Time: 6 hours to 3 minutes (max) per 100Ah battery capacity
- Maximum Absorption Rate: 30 minutes per 100Ah battery capacity
- Manual Equalization: Select start now
- Maximum Equalization Duration: 3-4 hours
- Re-Bulk Voltage offset: 0.1 volts
- Tail Current: 2.0A
- Temperature Compensation (mV/°C): 27.7 volts / 40° Celsius-25° Celsius
Note: Settings can be changed manually on the controller or from the PC Software. Follow the instructions of the manufacturer for the best results.
Steps in Solar Charge Controller Settings
While you set up your new solar charge controller, you should begin with properly wiring the controller to the battery bank and solar panels properly. Once the wiring is properly done and the controller detects the power, its screen will light up. Other steps are as follows:
1. Enter the settings menu by holding the menu button for a few seconds.
2. Charge current PV to Battery will be displayed
3. Battery Type Selection can be done by pressing the menu button for a long time.
4. The battery voltage will be auto-detected by the controller.
5. According to the user manual, set the setting for absorption charge voltage, low voltage cutoff value, float charge voltage, and low voltage recovery value.
6. If the system has an option for setting up the discharge value for DC, then set it as per the user manual.
7. Once the setting is done, the charge controller will instantly start the charging process.
Also See: How Many Batteries Can a 50 Watt Solar Panel Charge?
PWM Solar Charge Controller User Manual
The user manual of a PWM or a pulse width modulation solar charge controller contains information regarding the following:
1. LCD Display or Key
A solar charge controller has a digital display that displays a number of things on the panel through abbreviations or signs and symbols. Here is the list of those things and what they mean.
- A panel with a small sun shining indicates the solar panel charge.
- An arrow near the panel when it is bold black means the system is on Aqualation or buck when the arrow is flicking it means it is on float mode.
- A square filled with horizontal bars indicates battery.
- Near the battery sign, there is an arrow indicating the output.
- A bulb sign indicates the load
- V% indicates the voltage
- AH is for ampere hours
- A square-shaped box indicates a menu. It is used for switching between different displays. You can enter or exit the setting by pressing it for a long time.
- An up arrow is used to increase the value
- A down arrow showing a decrease in the value
2. LCD Display or Setting
To browse different interfaces in the solar charge controller settings, press the menu button. The LCD or key display discussed in point 1 is the main display. Next displays in order when you press the menu are:
- Float Voltage – The screen shows LIT, voltage, and the battery
- Discharge Reconnect – Shows LIT, voltage, battery, output (arrow), and load (bulb)
- Under voltage Protection – Displays LIT, voltage, empty battery symbol, and load (bulb)
- Work Mode – It displays hours (H), output (arrow), and load (bulb). OH, means dawn to dusk, 24H means load output is for 24 hours, and 1-23H means the load is on after sunset and closed after sunrise hours.
- Battery Type – LIT and the battery box with horizontal bars, determine the amount of battery charged and the type of battery. LIT is for lithium. After this, you are again on the main display.
Important: To switch On or Off the load manually on the main display, press the down key.
3. Product Features
- 3-stage PWM charge management
- A built-in industrial microcontroller with adjustable parameters
- A pulse width modulation solar charge controller has the following features:
- Battery Switching functions between lithium and lead battery. The lithium battery is the default setting and switches it to the battery type interface by holding it for 3 seconds.
- Dual metal–oxide–semiconductor field-effect transistor (MOSFET) Reverse current protection with low heating dissipation
- In-built protection for short-circuit open circuits, overload, and reverse
4. Safety Instructions
Every electrical appliance comes with a list of safety instructions that are prepared according to the appliance. A PWM controller has the following safety instructions mentioned in its user manual.
- Do not connect another charging source with the charge controller. The controller is suitable only for regulating solar modules.
- For the controller to recognize the battery type, ensure the battery has enough voltage before you begin the installation process.
- Install the controller on a well-ventilated and flat surface. While running, the controller will be heated.
- This controller is suitable for lithium batteries. All kinds of lead batteries (open, AGM, and gel) are also compatible with it.
- To minimize loss, keep the battery cable as short as possible.
5. System Connection
In solar charge controller settings, it contains instructions related to the connection. It tells you which port you need to connect to which wire.
- Connect the battery to the charge regulator (plus and minus)
- Connect the consumer to the charge regulator (plus and minus)
- Connect the photovoltaic module to the charge regulator (plus and minus)
6. Technical Parameter
This section contains all the information regarding the voltage, amperes, input, output, size, weight, etc. of the PWM solar charge controller.
- Batt voltage – 12 volts / 24 volts auto adapt.
- Charge current – 10A (KYZ 10), 20A (KYZ 20), 30A (KYZ 30)
- Discharge current – 10A (KYZ 10), 10A (KYZ 20), 10A (KYZ 30)
- Max solar input – less than 41 volts
- Model – (KYZ 10) (KYZ 20) (KYZ 30)
- Operating temperature – -35 ~+60° Celsius
- Size or weight – 133*70*355 millimeters or 140 grams
- Standby current – greater than 10 mA
- USB output – 5 volts / 2 A Max
The technical parameters of lithium and lead batteries under certain parameters are mentioned in the table below.
|Type of Battery||Equalization||Float||Undervoltage Protection||Discharge Reconnect|
|Lithium (LIT) battery||12.8 volts||12.0 volts (default, adjustable range 11.5-12.8 volts)||10.7 volts (defaults, adjustable range 9.0-11.0volts)||11.6 volts(defaults, adjustable range 11.0-11.7volts)|
|Lead acid battery (bAt)||14.4 volts||13.7 Volts (defaults, adjustable range13-15V)||10.7V (defaults, adjustable range9.0-11.0 Volts)||11.6 Volts (defaults, adjustable range11.0-11.7V)|
7. Trouble Shooting
Every electronic appliance faces some problem that can be easily resolved with troubleshooting. The basic problem and its solution are mentioned under the troubleshooting column in the PWMM user manual. Here I have mentioned the problem – probable cause – solution.
- Charge icon not on when sunny – Solar panel is open or reversed – Reconnect
- Load icon off – Battery low – Recharge
- Load icon off – Mode setting wrong – Set again
- Load icon slow flashing – Overload – Reduce load watt
- Load icon slow flashing – Short circuit protection – Auto-reconnect
- Power off – Battery too low reverse – Check battery or connection
Also See: What Size Inverter to Run a TV
Solar Charge Controller 24V Settings
After the solar charge controller settings for a 12V system, the 24V system is the most common charge controller used in residential solar power systems. The basic settings for this are mentioned in the user manual of your charge controller. However, here are a few basic settings that are for a 24V system.
- Battery Floating Charging Voltage is 27.4V
- Battery Over-discharging Protection Voltage is 21.6V to 22.8V
- Battery Overcharging Protection Voltage is 28.2V to 29V
- Solar charge controller settings for AGM battery
The solar charge controller setting for an AGM or Absorbent Glass Mat battery is also for 12 volts, 24 volts, or 48 volts. The maximum charge current should be at 50A maximum per 100Ah battery capacity. The absorption voltage should be 14.60 volts and the float voltage at 13.50 volts. Equalization voltage at 14.40 volts and bulk voltage offset at 0.10 volts. Absorption duration should be adaptive, and duration should be between 6 hours to 30 minutes per 100Ah battery capacity. The current percentage for equalization is at 25% and its duration at 4 hours max.
Solar Charge Controller Settings for Lithium Batteries
Before you begin setting up your lithium batteries, remember that lithium batteries do not require temperature compensation. Also, if you are replacing lead batteries with lithium batteries and the settings are set at Equalized this needs to be changed. To change this, select, EQE (Master equalizer enable/disable) on the charge controller display. This can also be done by selecting OFF the dip switch in other controllers. Some common settings for a multi-stage charge profile need to be set to the following settings:
- Charge voltage – 14.4 volts (3.6 VPC)
- Absorption time – 30 minutes to balance lithium cells
- Float voltage – 13.6 volts
- Resting voltage (default) – 3.4 VPC
Solar Charge Controller Settings for Lead Acid Battery
The lead acid battery is a classic configuration in a solar power system. Once you convert the battery type from lithium/AGM to lead acid battery, the original set parameters for a lead acid battery will be used. These configurations are already installed in the charge controller system. And sometimes, it is just plugging and using the system.
Well, today you learned about the alteration in solar charge controller settings in accordance with the type of batteries your inverter has. Also, solar charge controller voltage settings should be carefully done to get the maximum potential output from the solar charge controller.
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