As we know, the solar energy system mainly comprises solar panels, batteries, charge controllers, and inverters. For an efficient system, each component plays its part.
Solar panels capture light and convert it into electrical energy. This charges the batteries, which keeps the solar system working, even at night. An inverter converts the direct current electricity into alternating current energy.
Now the question remains, what does a charge controller do?
A charge controller is a device that:
- Controls and regulates the voltage and current from solar cells to the batteries
- Prevents the batteries from overcharging that can result in some severe damage
Optimum charging at the desired time boosts the performance of the system as well.
How to Connect Solar Panels to Multiple Charge Controllers?
Do you know you can wire your solar panels in a variety of ways?
Many try this DIY wiring to enhance energy production. If you are into this as well then keep on reading, we will discuss all the details of connecting your solar panels with multiple charge controllers later in this article.
As for now, let’s discuss the underlying panel array architectures.
Solar photovoltaic panels in series Combination
For series combinations, you need to attach a positive terminal of one panel to the negative terminal of another. As a result, we end up with one positive and one negative terminal.
For the off-grid solar panel system, you can attach these to a charge controller for the regulated charging of batteries.
For the grid-tied system without batteries back up, you can attach these two terminals to an inverter for DC to AC conversion.
In series combination, you can sum up different voltage ratings of each photovoltaic panel at the end.
The current rating remains the same in all series photovoltaic panels. If the charge controller requires above 24 volts, use a series combination.
Solar photovoltaic panels in parallel combination
In parallel combination, you need to connect all positive terminals and all negative terminals. Eventually, you are left with one positive and one negative terminal.
For the off-grid system, you can attach these terminals to the charge controller for regulated supplies to batteries.
Do you know at this stage the voltage ratings of each photovoltaic panel remain the same however current rating of each photovoltaic panel adds to the end terminals?
It boosts the current in the system, and if managed effectively, you can use it for charging the massive battery backup as well.
Solar photovoltaic panels in Mixed Combination
You need to experiment with a combination of both series and parallel photovoltaic panels when you require high wattage from your solar panel system.
Here is an essential point for you to keep in mind!
For series combination – you should prefer the same current ratings of panel array.
For parallel combination – you should prefer the same voltage ratings of the panel array.
Input capability of charge controller (in case of an off-grid system) and inverter (in case of a grid-tied system) limits the maximum voltage and maximum current from these mixed combinations of photovoltaic panel arrays.
High Power Charging Requirements – Multiple Charge Controller
Sizeable off-grid solar and battery backup systems require adequate charging to meet the requirements.
How to Wire the Charge Controllers if You Need Several of Them Instead of One?
Sometimes, a single charge controller cannot handle the charging supplies. Therefore, they need to install multiple charge controllers in parallel combination to separate photovoltaic panels.
This separate photovoltaic array is just like an independent solar system; however, to fulfill the requirements, these sub solar systems require a connection in parallel combination with multiple charge controllers.
It is important to note that the combination of all sub photovoltaic panel arrays must configure as per the controller specifications you choose to install with that array.
Moreover, combination of current ratings from all charge controllers must be within the battery specification supplied by the battery manufacturer.
It includes ampere charging and discharging rates per hour, specifically, as well.
When you install two charge controllers in parallel combination with independent solar panels array and charging a single battery, the current of both charge controllers will sum up, whereas voltage will remain the same.
If you want to increase the voltage rating of the solar system, you can design these panels in a series combination for pooled voltage of each photovoltaic panel (preferably sum up voltage should remain the same).
Later on, you can combine these panels (series) in parallel for the installation of multiple charge controllers.
Another vital point to remember is that plugging the panels of low power rating will drag the full power down.
There will be remarkable loss in the solar-generated power, and it will be more crucial in the parallel panels’ combinations. Hence, it would be best if you made an effort to have panels of the same ratings as it will assist each other’s performance.
If you have no option to connect dissimilar panels, then you should know:
- Series combination goes with the same current ratings
- Parallel combinations go with the same voltage ratings
Benefits of Both Single and Multiple Charge Controllers
- Prevents overcharging
- Prevents overvoltage thus improving battery life
- Prevents complete discharging of the battery
Single Charge Controller Pros and Cons
- Relatively inexpensive
- Can’t handle a large solar array’s output
Multiple Charge Controllers Pros and Cons
- Improves battery performance by 30%
- Can handle entire production of a large solar range
- Relatively expensive
How Does A Charge Controller Prevent Overcharging?
Charge controllers protect the battery from overcharging or unwanted discharging. They disconnect the solar panels load from the battery when its voltage value depletes to a certain level.
Moreover, they prevent reverse current through the photovoltaic cells during the night time.
Some controllers like MPPT (mentioned next in the article) maintain the optimum balance of current and voltage from the solar array and feed into a battery bank. Consequently, they alter the superfluous voltage from the solar panels into additional charging current.
Charge Controllers keep a constant check on the battery’s charge level thus maintaining its health.
Types of Charge Controllers
There are two types of charge controllers.
Standard Charge Controller
This controller is based on pulse width modulation technology and is not very efficient. This particular technology sends short pulses to the battery and is not that agile.
The controller is economical, and you can use it in the system having robust, steady, and constant solar radiation. It’s unable to optimize an entire array if based on differences between panels.
Maximum Power Point Tracking
The controller is based on maximum power point tracking technology and is highly efficient due to its ability to extract all power available in the panels.
You’ll find it in significant systems. It increases the solar array’s effectiveness by 30%.
The controller with Maximum Power Point Tracking technology connects photovoltaic panels in series for high voltage, to have high wattage from the solar system. It also keeps current low to support long wire connection till panels.
The use of a blocking diode is also every day in these combinations. It prevents damage to the entire array even if a short circuit occurs at a single panel strip.
Moreover, a diode should have a low threshold voltage, which ensures low power dissipation. The best diode used for the photovoltaic application is the Schottky diode.
Do we hope that by now, you not only know how to connect solar panels to multiple charge controllers? But also how by designing the parallel photovoltaic panels’ combination of similar voltage rating, you can get maximum output.
In addition to this, you now know if we use the maximum power point tracking (MPPT) technology-based multi charge controller, we can manage to have an efficient solar system.
Since a high rating current can damage the parts of our system, we have tried to optimize the output power by incorporating the series combination of photovoltaic panels. It results in high voltage.