I often see people online saying that you can’t run two different solar panels connected in parallel into one battery, and this couldn’t be further than the truth.
If you have an 80W solar blanket, you can absolutely hook it together with a 200W panel and feed it into your battery, providing you do a couple of checks beforehand.
You will likely suffer some losses, but it works (and some solar controllers are much better at it than others), and I’ve been doing it for years without any negative side affects.
If you really want to keep them separate, you can run each panel through its own regulator, and then feed both regulators into the same battery, but that’s another story.
We often run a 120W solar panel on the roof of our camper trailer, with a 200W kings solar blanket through our Enerdrive DCDC charger to the batteries, and it works perfectly fine.
On occasion, I’ve even hooked our 200W Low Energy Developments Solar Panel on our Isuzu Dmax into the mix, so we’ve got 3 different panels all feeding into the same solar controller.
Now, there are a couple of things that you want to check before doing this, but for the most part you shouldn’t have any issues.
Check the voltage
Before you do this, you should check the open circuit voltage of the panels, and make sure that they are somewhat similar.
Our Renogy Solar Panels for example, are 27V, and pairing them with a normal 12V solar panel wouldn’t work very well.
Is your solar controller suitable?
Next up, you need to ensure that the solar controller that is controlling what power actually goes into your batteries is suitable.
If you had a cheap 10 amp PWM regulator, hooking multiple panels that exceed the 10 amps output would be a recipe for disaster. To give you an idea, our Enerdrive DC2DC is good for 500W of solar, and a maximum of 600W if you are OK with it shaving some off in peak sun.
As a result of this, connecting two 200W panels and a 120W panel together is no issue, and I ran our setup for about a week like this in Shark Bay Caravan Park whilst we ran the induction cooktop for our primary food cooking setup.
In short, yes, its possible to run different solar panels together, but you need to check that they aren’t vastly different, and that your regulator can take the power correctly.