When it comes to selecting the most appropriate portable solar products and accessories for your 4x4 or camping needs, the possibilities are truly endless.
Solar panel, solar blanket, fixed panel, regulators, Anderson to Anderson, it’s enough to make your head spin.
But don’t get weighed down with all of the technical jargon, REDARC are here to help with a run-down of some of the most commonly asked questions about solar regulators.
Why do I need a solar regulator?
The power of the sun is very powerful. In fact, it is so powerful that if you use the sun’s energy via solar panels it can fry your battery through over-charging.
Think about it this way; say your battery is an ant, and the solar panel is a magnifying glass. Now, what happens to the poor ant in full sun when you hover the magnifying glass over it? We won’t go into the gory details.
That’s why you need a solar regulator. A solar regulator is designed to accept the voltage from the solar panel and provide an output voltage that is safe and useable to charge a battery.


What is the difference between MPPT and PWM regulators?
There are two types of solar regulators you can get on the market; Pulse With Modulation (PWM) regulators and Maximum Power Point Tracking (MPPT) regulators.
PWM controllers, to put it simply, turn the solar input on and off (several times per second) and when the panel has connected the battery, a PWM regulator will be looking at the battery voltage and will begin switching the panel on or off when the battery voltage starts to rise. This will limit the power transferred to the battery and therefore limit the voltage from rising further.
MPPT regulators, on the other hand, can be likened to a voltage converter. The regulator actually simulates a load to the panel to keep the panel at its best performing point, where the panel produces its most power based on the conditions. This point will continually change based on the changes in the conditions, and the regulator will track this point.
MPPT regulators also ensure that you get the most power possible from your solar panels at any point in time and are particularly effective during low light level conditions. During low light level situations, it will compensate for the low light level and find the new point at which the solar cell delivers its maximum power output.


If the solar system you are setting up is small and you are trying to work to a budget, then a good quality PWM regulator can be an affordable option and will still do a good job of safely charging your battery. If you have a large solar setup and battery bank to be supplied, then MPPT is definitely the way to go.


Where should I position/mount my solar regulator?
A lot of the cheap and inferior solar panels available on the market often have the solar regulator attached to the back of the solar panel. However, it is recommended to have the regulator as close to the battery, which will reduce voltage drop to the batteries. That way you increase the efficiency of your whole system.
This is why REDARC’s solar range has solar regulators available be purchased separately, so you can mix and match to the wide range of solar panels available and ensure you have the correct setup.
If I have an In-vehicle battery charger, do I still need a solar regulator?
Unless your DC to DC charger has an inbuilt solar regulator, then yes you do require a solar regulator. Some people make the mistake of using a regulated panel, with a battery charger that has an in-built solar regulator to charge their battery. This is a mistake because:
The original regulator on the panel is unlikely to turn on unless it is connected directly to a battery. Even if it did not turn on, the regulator’s output would not have the same characteristics as an unregulated panel range, so the BCDC* or BMS* MPPT regulator would not be able to track the Maximum Power Point of the panel.
The BCDC and BMS range incorporate MPPT solar regulators and are only suitable for use with unregulated 12V (nominal) panels.


Need help in getting started with your solar journey? Use our solar calculator to get the best solar solutions for your needs.
Looking to start your 4x4, camper trailer or caravan upgrade but not sure what products will allow you to travel the way you want? Take the REDARC Hilux product tour to find out what products are best for your power management and towing needs.