RV Solar Q&A: Flexible Panels, Storage, Roof Mounting, and Generator Starting
- BBB Marketing Team
- 6 days ago
- 3 min read
RV solar systems bring up a lot of great questions, especially when you’re trying to make the right choices for your roof, batteries, and long-term setup. In this quick Q&A, we’re answering a few common questions from RV owners about flexible panels, solar storage, mounting feet, and generator starting options.
Should you attach flexible solar panels directly to an RV roof?
We do not recommend directly attaching flexible solar panels to an RV roof membrane.
Flexible panels can fail over time as they bend, flex, and heat up. Even when a panel starts to fail, it can still produce power, which may lead to hot spots or burn marks. We have seen plenty of RV roofs where flexible panels were removed and burn marks were left behind.
There’s also the removal issue. If you use a strong adhesive like Lexel or similar products directly on the RV roof, pulling the panel up later can damage or tear the roof membrane.
A better option is to either use rigid solar panels or mount flexible panels to something more heat-resistant and removable, like a fiberglass board, before securing that to the roof.
Should solar be disconnected from the charge controller during storage?
In most modern RV solar systems, you usually do not need to disconnect the solar panels from the charge controller for storage. Older solar setups sometimes allowed power to flow backward at night, which could slowly drain the battery. Modern solar panels and charge controllers typically include diodes or protections that prevent that from happening.
For storage, the bigger concern is not overnight drain. It’s making sure the battery is not being charged or discharged too aggressively while the RV is unattended. If your system allows it, lowering the charge rate can be a smart move, especially if the RV is stored outside. Leaving solar connected can help keep the battery maintained.
The exception would be very old panels or outdated equipment. If you are using used solar panels that are decades old, the setup may need to be checked more carefully.
How do you know where to screw solar panel feet into an RV roof?
Most RV roofs have decking under the membrane, often around half-inch decking. When mounting standard Z-bracket solar feet, you are usually not going to land every foot perfectly into a roof truss.
Because of that, many installs are secured into the roof decking itself. The key is using the right screw length and sealing everything properly.
At Big Beard Battery, we typically use a 1-inch screw with a larger pan head. We avoid longer screws because there can be wiring in the small attic space under the roof, especially near the edges of the RV where the space gets tighter.
Once the feet are secured, the mounting points need to be sealed correctly using the proper tape and sealant. When done right, the panel should sit securely without creating excessive lift.
Can a car audio capacitor replace a 12V battery for starting a generator?
A car audio capacitor is not a simple replacement for a 12V battery when starting a generator.
The issue is matching the capacitor to the generator’s starting needs. You cannot just grab any capacitor and expect it to work safely or reliably. A generator needs the right amount of stored energy and the right discharge behavior to start properly.
Another thing to remember is that a capacitor still needs a charge source. Unlike a true battery, a capacitor will lose voltage over time. That means you would still need a battery or another source to keep the capacitor charged.
In most cases, a properly sized battery is still the better and more reliable option for generator starting.
Need help with your RV solar system?
Whether you’re trying to choose the right solar panels, store your RV properly, mount panels safely, or build a full off-grid power system, Big Beard Battery can help.
Head to BigBeardBattery.com, fill out the Solar Design Form, and one of our certified solar experts will help you get started.
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