Portable solar panels need a regulator to be used. If a regulator is not connected to a portable solar panel, there is a chance of both overcharging and undercharging the battery bank used with the panels. There are two types of regulators, called PWM and MPPT.
In this article, I will go into depth about why you need to use a regulator with portable solar panels and the two main types of regulators. I will also provide things to consider when shopping for a regulator and answer the question of if you can use a portable solar panel without a regulator.
Why Portable Solar Panels Need a Regulator?
Portable solar panels need a regulator to prevent any damage to the solar panels or the battery banks that store the power generated by the portable solar panels. When the portable solar panel is charging the battery bank, the regulator will stop charging when the battery bank is getting close to fully charged.
More advanced regulators can also monitor temperature and adjust the battery charging based on the temperature. For example, the regulator will allow the battery bank to charge to a higher voltage in cold temperatures and lower voltages in hotter temperatures.
What Is a Regulator for Portable Solar Panels?
A regulator, or a solar charge controller, regulates the amount of power that goes into the battery bank from a solar panel. The regulator is used to prevent both overcharging and undercharging of the battery bank used in conjunction with the portable solar panels.
Undercharging, or running the battery bank until it is out of power, lowers the life expectancy of the battery bank significantly.
On the other hand, overcharging the battery bank may cause excessive gassing in a lead-acid battery that can “boil” the water, exposing the battery’s plates. In a worst-case scenario, this can result in an explosion.
Types of Regulators for Portable Solar Panels
There are two common regulators used with portable solar panels: pulse width modulation (PWM) and maximum power point tracking (MPPT).
Choosing which regulator type you want depends on many factors, including:
- How sophisticated your solar system is
- The voltage you need
- Your monetary budget
- The climate in which you use your portable solar panel
Here’s a great, in-depth YouTube video comparing PWM and MPPT regulators:
Pulse Width Modulation (PWM)
The original type of regulator, pulse width modulation (PWM) regulators use a switch between the portable solar panels and the battery bank. Because PWM regulators use a switch, the portable solar panel voltage during operation is the same as the battery voltage. This means that you need to use nominal voltage portable solar panels with a PWM regulator.
Even though you use everything with nominal voltage, PWM regulators will always operate below the maximum power voltage (Vmp).
PWM regulators are the better option when you have shorter wires and when you have nominal voltage solar modules. For example, deserts are a great place to use a PWM regulator, as sunlight is constant, and it is unlikely that wasted electricity will be an issue.
Maximum Power Point Tracking (MPPT)
Maximum power point tracking (MPPT) regulators are more sophisticated than PWM regulators. They adjust and track the input voltage and current of the portable solar panels to find the best voltage needed to generate the most power at any specific time.
These regulators can also be used with higher voltage portable solar panels, making them more versatile than PWM regulators.
If you will be using your portable solar panels in areas with constantly changing sunlight and temperatures, using an MPPT regulator is best. They can maximize the electrical output in challenging conditions, such as a hard, snowy winter.
Things To Consider When Choosing a Regulator for Your Portable Solar Panel
Whether you’re buying a PWM or MPPT regulator for your portable solar panel, there are other things you need to take into account. Do you want your regulator to work automatically or manually? Do you want to be able to monitor the regulator remotely? What about being able to change the voltage setpoint?
Let’s talk a little about some things you should consider when choosing a regulator to use with your portable solar panel.
Automatic or Manual Load Control
Load control, or the ability to turn off the battery bank’s output when the regulator senses that the bank is extremely low, is used in most portable solar panel regulators. Because of that, the question is whether or not you want a regulator with automatic load control or manual load control.
As the name implies, automatic load control regulators automatically turn on and off the battery bank output when it detects that the change needs to happen. On the other hand, manual load control means you have to manually alter the battery bank output.
Remote Access
If you don’t mind spending a little more money on your regulator, you could get one that allows you to keep an eye on and control it remotely.
A remote-accessible solar regulator is terrific if, for example, you take a long hike while your portable solar panel is charging the battery bank on your RV miles away. You can check on the regulator and the charge status while on the hike.
Multi-Voltage Functionality
Multi-voltage functionality refers to the regulator’s ability to change the voltage setpoint or the maximum voltage the regulator allows for a battery bank charge. In general, you want your voltage setpoint to be directly inverse to the battery bank’s temperature for it to charge fully without overheating.
Having a regulator with multi-voltage functionality can change the voltage setpoint as the seasons change. To keep the voltage setpoint directly inverse to the battery bank’s temperature, you’d want to raise the setpoint in fall and winter and lower it during spring and summer.
Can a Portable Solar Panel Be Used Without a Regulator?
You can use a portable solar panel without a regulator. However, doing so is not recommended. Not having a regulator increases the chances of electrical surges. The battery bank connected to the portable solar panel is more likely to undercharge or overcharge.
Despite this, some lower wattage portable solar panels don’t need regulators. Sol Voltaics states that “small maintenance” solar panels, generally 1-5 watt portable solar panels, don’t need regulators.
Conclusion
Portable solar panels need regulators to ensure the total off-grid solar system works properly so that the battery banks don’t get overcharged or undercharged. Regulators can also monitor temperatures and adjust the voltage a battery bank can charge.
There are two types of regulators, also known as charge controllers, that you can use with portable solar panels:
- Pulse width modulation (PWM)
- Maximum power point tracking (MPPT)
