One of the most frequently asked questions from people new to Victron solar systems is: "Do I have to use Victron solar panels with a Victron MPPT?" The short answer is no. Victron MPPT charge controllers work with any solar panel from any manufacturer. Here's everything you need to know about compatibility.
Victron MPPTs Are Panel-Agnostic
Victron SmartSolar and BlueSolar MPPT controllers are designed to work with any solar panel that produces DC voltage within the controller's operating range. The MPPT algorithm doesn't care about the panel brand — it simply tracks the maximum power point of whatever PV source is connected.
You can use panels from JA Solar, Trina, LONGi, Canadian Solar, Renogy, Rich Solar, or any other manufacturer. You can even mix panel brands in certain configurations (though this comes with caveats — see below).
What You Need to Check
While any panel will physically work, you must check two critical specifications:
1. Open Circuit Voltage (Voc)
Your panel string's total Voc — adjusted for cold temperatures — must be below the controller's maximum PV voltage. This is the first number in the MPPT model name (75V, 100V, 150V, or 250V).
Find the Voc on your panel's datasheet or rear label. If wiring panels in series, add the Voc values together. Then apply a cold-weather correction:
- UK climate: multiply total Voc by 1.10 to 1.15
- Very cold climates (-20°C and below): multiply by 1.15 to 1.20
The corrected Voc must stay below the controller's limit. Exceeding it will permanently damage the MPPT.
2. Short Circuit Current (Isc)
For the 75V and 100V MPPT models, Victron specifies a maximum PV short-circuit current (Isc). This is typically printed in the MPPT datasheet. If you're wiring panels in parallel, the total Isc (sum of all panels) should not exceed this limit.
The larger 150V and 250V models are less sensitive to PV Isc because they handle higher input currents by design.
Using the Victron MPPT Calculator with Third-Party Panels
The Victron MPPT sizing calculator has a database of Victron panels, but you can also enter custom panel specifications manually. Here's how:
- Go to the Victron MPPT calculator website.
- Select your battery voltage and MPPT model.
- Under the panel selection, choose "User defined".
- Enter the Voc, Isc, Vmp, Imp, and temperature coefficients from your panel's datasheet.
- Enter the number of panels and your wiring configuration (series, parallel, or series-parallel).
- The calculator will tell you if the configuration is safe for your selected MPPT.
The temperature coefficients (typically α for Isc, β for Voc, and γ for Pmax) are usually listed on the datasheet as percentages per degree Celsius. The Victron calculator uses these to determine worst-case voltage at your location's minimum expected temperature.
Can You Mix Different Panel Brands?
Technically yes, but with important caveats:
Same Specs, Different Brands: Generally Fine
If two panels from different manufacturers have the same (or very similar) Vmp, Imp, Voc, and Isc values, they can be wired together in series or parallel without issues. The MPPT will track the combined power point effectively.
Different Specs: Use Parallel Only
If panels have different electrical characteristics (different Vmp, Imp, or wattage), you should wire them in parallel, not series. In a series string, all panels are forced to carry the same current — the weakest panel limits the entire string. In parallel, each panel operates at its own optimal current.
The Best Practice
For maximum energy harvest, use identical panels wherever possible. If you must mix panels, wire them in parallel. And if you have very different panels (e.g., a 100W and a 300W), consider using separate MPPT controllers — one for each panel type.
What About Victron's Own Solar Panels?
Victron does sell their own monocrystalline panels, and they're good quality. But they're not specifically optimised for Victron MPPTs — any panel of equivalent specifications will perform identically. The advantage of Victron panels is convenience (guaranteed compatibility and specs) and availability through Victron dealers, not any electrical advantage.
In fact, for larger installations (300W+ panels), most people use third-party panels from major manufacturers like JA Solar or LONGi because they're more cost-effective at higher wattages and more widely available.
Common Compatibility Questions
"Can I use 24V panels with a 12V battery?"
Yes, absolutely. MPPT controllers are designed for this. A 24V-type panel (Voc around 40V) works perfectly with a 12V battery. The MPPT steps down the higher panel voltage to the correct battery charging voltage, and the voltage mismatch actually improves MPPT efficiency.
"Can I use residential roof panels (60-cell / 120-half-cell)?"
Yes. Standard residential 300–410W panels work great with Victron MPPTs. Just check that the Voc doesn't exceed your controller's maximum, especially when wiring in series. A typical 400W panel has a Voc around 49V — two in series (98V with cold correction up to 110V) would need a 150V controller.
"Can I use flexible/thin-film panels?"
Yes. Flexible monocrystalline panels and thin-film panels both produce DC voltage that Victron MPPTs can convert. Just check the Voc and Isc specs as you would with any panel.
"Do I lose my Victron warranty by using third-party panels?"
No. Your Victron MPPT warranty is not affected by the brand of solar panel you use. The warranty would only be voided if you exceed the controller's electrical specifications (e.g., overvoltage damage from a panel string with too-high Voc).
Summary
Victron MPPT charge controllers work with any solar panel. There's no brand lock-in and no performance penalty for using third-party panels. Just ensure your panel string's Voc (with cold weather correction) stays below the MPPT's voltage limit, and keep total Isc within the controller's rated input current. Use the Victron MPPT calculator with custom panel specs to verify any configuration before purchasing.
