The Solar Charge Controller plays an essential role in the operation of your solar system. It communicates between the solar panel and the battery storage to ensure everything is operating as it should, which will help extend the life of the batteries.
The Solar Charge Controller is a voltage regulator that keeps your deep cycle batteries from overcharging during the day by making sure that they do not receive too much solar energy during the day, which could damage the internal components of the battery.
As soon as the sunlight disappears, the controller ensures that there is no power flowing backwards from your solar panels, blocking reverse currents from flowing.
In order for your solar system to function properly, a solar charge controller is an essential part of that system. Without one, you risk irreversible damage to your battery and a shorter lifetime for your solar panels.
How Do Solar Charge Controllers Work?
Solar Charge Controllers act as a middleman between your batteries and solar panels. Your batteries communicate with the solar charge controller, which relays the message to the solar panels.
There is an energy current flowing into the controller's semiconductor, which opens or closes based on the current needs of your battery at any given time.
There is a specific voltage capacity that each deep cycle battery has, and any voltage above that will be detrimental to the life and health of your battery.
Depending on what your battery needs, a Charge Controller regulates the voltage acquired from the solar panels and regulates the flow of energy from the panels based on how much energy is needed by the battery.
There are overload protection circuits that prevent the battery system from overheating when facing too much current, and they are equipped with low voltage disconnect circuits that automatically disconnect your battery before it overdischarges and damages itself as a result.
Two Main RV Solar Charge Controller Styles
A solar charge controller can be found in a wide range of shapes and sizes, all of which fulfil different functions and have varying strengths and weaknesses.
As long as your set-up stipulates, there will be a solar charge controller that is a perfect match for you. There are two main categories of solar charge controllers that you can choose from:
- Pulse Width Modulation (PWM) Charge Controller
- Maximum Power Point Track (MPPT) Charge controller
In order to find the appropriate controller for your rig, you must first understand these two categories and decide which one is most suitable for you based on your needs.
As a result of Pulse Width Modulation, your charge controller works in the same way as a heartbeat. You are sending controlled pulses of energy from your solar panel to your battery system instead of a constant flow of electricity.
The controller will communicate with your battery to get up-to-date information about what it needs in order to generate the pulsation, which affects the rhythm of the pulsation.
PWM controllers are capable of understanding when to send a short burst of energy to your battery in order to trickle charge it, and when to send longer pulses of energy in order to fully charge your battery. This allows them to be highly effective in less energy-intensive applications.
Generally, these devices can't handle much more than a 12v solar panel array, and if you have a number of solar panels in your set-up, you'll need to ensure that they are wired in parallel, otherwise they won't function properly.
As a rule, these types of controllers will be able to convert 75% of the energy drawn by your solar panels into usable battery energy at maximum efficiency.
MPPT Charge Controller
A MPPT Controller can be used to control large solar arrays and they are widely preferred by RVers looking to live in their campervans full-time or by those planning to stay off-grid for several weeks at a time.
A MPPT charge controller does more than just communicate with your battery system in order to determine what charge level your battery system needs. It can also communicate sophisticatedly with your solar panels in order to find the optimal voltage for your system.
It is this communication with your solar panels that gives MPPT its name. The MPPT automatically adjusts itself to your solar draw in order to maximize power, which can result in 30% more charge than the PWM controller.
Additionally, MPPTs convert the voltage and power of your solar panel into a form that is more digestible for your battery system.
You can use them to convert volts to amps, which prevents your solar panels from wasting energy.
Solar MPPTs can convert 96% of your solar draw into usable energy.
What Is Better MPPT Or PWM?
It is true that PWM controllers can provide a more straightforward job at a lower price point than MPPT chargers, yet MPPT controllers are designed to handle much more extensive setups and are more reliable for long-term use than PWM controllers.
In order to keep your lights and fans powered up on weekend trips, you will only need a PWM controller and a full battery before you set off on your trip if you have just a few lights and fans to run.
You should seriously consider investing the extra money in an MPPT charger if you have a heavy-duty system or intend to rely on a solar charger for several weeks at a time.
It is a good indicator that you need an MPPT controller when you have multiple solar panel systems, as this will give you the extra boost that is needed.
The efficiency of PWM is all you need if you just want to trickle charge your battery to ensure it's ready to go when you are, so that it's always ready when you are.
In the case of a system involving more than two solar panels or 150W of power, an MPPT solar charge controller will have to be employed for the more extensive charging capabilities it provides.