Connecting the solar charge controller – what to look out for
Do you want to connect a solar charge controller in your motorhome? We explain what you should look out for when choosing the right solar charge controller and give you tips for installation.
A solar charge controller is a device that controls the energy transfer between the solar module and the battery. The solar charge controller ensures that the battery is optimally charged by regulating the voltage and current and adapting them perfectly to the battery.
In this article, we explain what you should look out for when selecting and installing a solar charge controller in your motorhome.
Choosing the right solar charge controller
When choosing the right solar charge controller for you, there are a few important things to consider. We will show you what is important.
PWM or MPPT solar charge controller?
Solar charge controllers in motorhomes usually work with one of these two technologies: PWM (pulse width modulation) or MPPT (maximum power point tracking).
PWM solar controller
A PWM solar charge controller regulates the voltage and current of the solar modules to the battery by pulsing circuits to prevent overcharging. It is less expensive, but is best suited to systems where the solar module voltage is close to the battery voltage.
MPPT solar controller
MPPT charge controllers maximize the energy yield by continuously tracking the optimum power point of the solar modules and thus generate up to 30 % more energy than PWM charge controllers, especially in changing weather conditions.
Check compatibility
Solar charge controller & battery
Compatibility with the solar panel and the battery to be charged is very important when selecting a suitable solar charge controller.
Battery voltage:
First of all, make sure that the solar charge controller also supports the voltage of your battery. Specifically: If the battery you want to charge has an operating voltage of 12V, the solar charge controller must also support 12V.
99% of motorhomes are fitted with 12 V batteries.
Battery type:
The solar charge controller should definitely support the type of battery you want to charge. This is crucial for a long service life of your battery.
⇨ All solar charge controllers from Supervolt can be adjusted to the most common battery types
Solar charge controller & solar module
Compatibility between the solar charge controller and solar module(s) must also be ensured. You must ensure that the solar charge controller is designed for the max. voltage (V), max. current (A) and max. power (W) of the connected solar module.
So take a close look at the technical data of both components before buying. If in doubt, a solar charge controller of the next higher level should be selected.
At Supervolt you will find MPPT solar charge controllers in three power levels:
Connecting the solar charge controller
Connecting a solar charge controller in a motorhome is not particularly difficult if you pay attention to a few important things. We explain what you need to look out for when installing it.
Important: Here we explain the basic installation of a solar charge controller. It is important to find out how to install the solar controller of your choice and to follow the relevant operating instructions.
Installation location
As a solar charge controller can become warm under full load, there should be room for air circulation. Further information on this can be found in the operating instructions for the device.
The installation position of a solar charge controller can be freely selected.
Cable cross-section
The choice of the correct cable cross-section for connecting the solar charge controller to your battery and the solar panel should not be underestimated.
If the cable cross-section is too small, you not only risk a drop in performance, but also a cable fire.
To find a suitable cable cross-section for your project, we recommend the following online calculator for solar cables:
Cabling
Ensure that the wiring is carried out in the correct order. To avoid possible installation errors, observe the following sequence:
1. first connect the temperature sensor supplied. External devices for the RS485 communication interface can also be connected directly.
2. if you have a solar charge controller with an additional load connection, you can connect this now (e.g. Supervolt solar charge controller 40A & 60A).
⇨ If no load is to be connected or is not available, this step is simply skipped
3 Next, the solar controller can be connected directly to the battery. With an EBL, the solar charge controller is connected to the connection points provided on the EBL (see operating instructions for the EBL). Pay attention to the correct polarity during this step!
If you have done everything correctly, the solar charge controller is now supplied with power and the display of the device lights up (if there is a display).
With solar charge controllers from Supervolt you can now use the Supervolt Solar APP to connect directly to the solar charge controller. After connecting to the device, you should first change the battery type to your battery.
4. after the solar charge controller has been wired to the battery, the solar panel can now also be connected.
ATTENTION
As the solar panel generates electricity when exposed to light, it should be covered before connecting it to the solar charge controller. Even with the slightest incidence of light, the full voltage of the solar panels is conducted through the cables.
As already mentioned, it is also important to select the correct cable cross-section when connecting the solar panel to the controller. The various solar panels on the market sometimes differ greatly in terms of current (A) and voltage (V), even though they generate the same power (W).
5. as soon as the solar panel has been connected correctly, it can be covered. In the Supervolt Solar APP you can now also view the performance of the solar panel in real time.
Fuses
To prevent damage due to short circuits, we strongly recommend integrating fuses between the solar panel & solar charge controller and the battery & solar charge controller – see circuit diagram above.
You can find out which fuses are recommended in the operating instructions for your solar charge controller.
In an installation with an EBL, no additional fuses are required as these are integrated in the EBL.
Supervolt solar charge controller
You are sure to find a suitable solar charge controller for your project with us.
Our highly efficient MPPT solar charge controllers are impressive:
- MPPT technology with a tracking efficiency of >99.9%
- High charge conversion efficiency of up to 98
- LED display (for 40A & 60A)
- Waterproof design, suitable for indoor and outdoor use
- Automatic detection of 12/24V
- Choice between liquid, gel, AGM and lithium batteries
- Four-stage charging mode: Quick charge, boost, equalization, trickle charge
- Fully automatic electronic protection function
- Supervolt APP for monitoring the solar power
- and much more.
