So you've got a solar panel set up and it's doing its job – but somewhere between the fridge, the lights, the fan, and keeping your phone charged, you're starting to wonder if one panel is enough. The good news is that it probably isn't a hardware problem. It's a wattage problem, and there's a straightforward fix: connect more panels.
Whether you're running a caravan, a 4WD setup, a camper trailer, or a remote off-grid station, combining multiple solar panels is one of the most practical ways to squeeze more charge into your battery bank. This guide walks you through why you might need more solar input, how to connect panels together, and the accessories you'll need to do it properly.
Why One Solar Panel Isn't Always Enough
A single 12V solar panel is brilliant for light duty use – keeping a small battery topped up, running a fridge overnight, or powering a few LED lights. But once your setup grows, the maths starts working against you pretty quickly.
Think about a typical extended camping trip. You might have a 12V compressor fridge drawing around 3 to 5 amps per hour, a fan running through the night, USB devices constantly charging, and maybe some 12V lighting. That's a meaningful daily draw on your auxiliary battery, and if you're parked up for a few days in a row, one panel – especially a smaller one – may simply not be generating enough power to keep up, let alone fully recharge a depleted battery before the next evening.
There are a few common scenarios where connecting multiple panels makes real sense:
- Extended off-grid trips where you can't rely on driving to recharge via a DCDC charger.
- Setups with high-draw appliances like large compressor fridges, electric blankets, or induction cooktops.
- Caravans or camper trailers with large battery banks that take longer to replenish.
- Seasonal trips where shorter days or overcast skies reduce your solar window.
- Fixed rooftop installations where you have multiple panels already in place and want to maximise output.
In all of these situations, adding a second (or third, or fourth) panel and connecting them together is a cost-effective way to get more energy into your system.
Series vs Parallel: Understanding the Two Connection Methods
Before you grab your cables, it's worth understanding the two main ways to wire panels together – series and parallel – because they produce different electrical outcomes, and the right choice depends on your system.
Connecting Panels in Parallel
Parallel wiring is the most common approach for 12V camping and caravan setups. When you connect panels in parallel, you join the positive terminals together and the negative terminals together. The result is that the voltage stays the same as a single panel, but the current (amps) adds up.
For example, if you have two 170W panels each producing 18V and around 9.4A, connecting them in parallel gives you a combined output of still 18V but roughly 18.8A – effectively doubling your charging current. Your charge controller sees a 12V-compatible input, and everything plays nicely with a standard 12V battery setup.
Parallel is generally preferred when:
- You want to keep your system voltage at 12V
- You're using a PWM charge controller
- You have panels that are the same wattage and voltage
- You want a simpler, more forgiving wiring configuration
It's worth noting that with parallel connections, if one panel is shaded or underperforming, it can drag down the output of the others. This is where bypass diodes (built into most quality panels, including KickAss fixed glass panels) help minimise the impact.
Connecting Panels in Series
Series wiring takes a different approach. You connect the positive terminal of one panel to the negative terminal of the next, forming a chain. This time, the voltage multiplies while the current stays the same.
Using the same example – two 170W panels each at 18V and 9.4A in series would give you 36V at 9.4A. That's a higher-voltage input that isn't compatible with a basic PWM controller designed for 12V systems. However, it works very well with an MPPT charge controller, which is designed to accept a wide voltage range and convert it efficiently down to whatever your battery needs.
Series wiring is often used in larger or more sophisticated systems, particularly where:
- You're using a quality MPPT charge controller that accepts higher input voltages
- You have long cable runs where higher voltage reduces resistive losses
- Your system is designed around 24V or 48V battery banks
Many KickAss fixed glass solar panels are noted as being configured for series connection, which pairs them perfectly with the KickAss MPPT controllers.
Series-Parallel: Getting the Best of Both
When connecting three or more panels, you can also combine both methods – known as series-parallel wiring. For instance, with four panels you might connect two pairs in series, then connect those two series strings in parallel. This balances voltage and current in a way that suits many MPPT controllers. It's a slightly more advanced configuration, but it opens up a lot of flexibility when scaling up a larger system.
What Panels Can You Connect Together?
A common question is whether you can mix and match different panels. It’s better not to – and here’s why.
When connecting panels in parallel, they should have the same voltage rating. If one panel has a higher voltage than the others, it can cause uneven loading and reduce overall efficiency. When wiring in series, the panels should have the same current rating. Mismatched panels can result in the weaker panel limiting the output of the stronger one.
The cleanest approach, and the one that avoids headaches, is to use identical panels – same brand, same model, same wattage. KickAss offers its fixed glass panels in a range of wattages (from 80W up to 350W), as well as folding portable panels from 60W up to 300W and solar blankets from 50W to 200W. Sticking to matching panels in your array keeps your system balanced and predictable.
The Accessories You'll Need
Connecting multiple panels properly requires a few key pieces of hardware. Getting these right is just as important as the panels themselves.
A Solar Charge Controller
No matter how many panels you connect, all the output needs to pass through a solar charge controller before it reaches your battery. The controller's job is to regulate the charging voltage and prevent overcharging, which can damage your battery.
There are two types to be aware of:
- PWM (Pulse Width Modulation) controllers are basic, affordable models. They work well for smaller systems with panels wired in parallel at 12V. The KickAss 30A PWM Solar Regulator is a solid option for straightforward setups.
- MPPT (Maximum Power Point Tracking) controllers are more sophisticated and significantly more efficient – often 20 to 30 per cent better than PWM in real-world conditions. They can accept a much wider input voltage range, making them ideal for panels wired in series or for larger arrays. KickAss offers both a 20A MPPT Solar Charge Controller and a 40A MPPT Solar Charge Controller, both of which support parallel panel configurations, are lithium-compatible, and include Bluetooth app monitoring.
As a general guide, add up the total wattage of all your panels and divide by your battery voltage to get an approximate amp rating. For example, two 170W panels at 12V would give you roughly 28A, so a 20A controller might be cutting it close and a 30A or 40A unit would be more comfortable. It's always better to have a controller with headroom than to run it at its maximum.
KickAss also offers a compact Smart 20A MPPT In-Line Solar Charge Controller with integrated Bluetooth – a plug-and-play option that's great for portable setups or where space is at a premium.
Branch Connectors (for Parallel Wiring)
If you're wiring panels in parallel, you'll need a way to combine the outputs before they reach the charge controller. This is where MC4 branch connectors (also called T-branch or Y-connectors) come in. They allow you to join two panel outputs together cleanly and weatherproof – one connector for the positive leads and one for the negative leads.
The KickAss Solar T Branch Female and Male Connector is purpose-built for exactly this. Rated 4.7 stars from over a dozen reviews, it's a simple and affordable piece of kit that makes parallel wiring clean and secure. If you're connecting three or more panels, you can daisy-chain multiple branch connectors together.
Extension Cables
Depending on your setup, you may need additional cable length to reach from your panels to your charge controller or battery. This is especially relevant for fixed rooftop installations on caravans or 4WDs where the controller is mounted inside.
The KickAss 5m Solar Panel PV to Anderson Extension Cable is engineered specifically for fixed glass solar panels and is MC4 compatible. At 5 metres, it gives you plenty of run to work with, and it's built to handle Australian conditions.
When sizing your cable, keep in mind that longer runs and higher currents require heavier gauge wire to avoid resistive losses. If you're running multiple panels in parallel (higher current), it's worth checking that your cable gauge is up to the job.
Mounting Hardware (for Fixed Panels)
If you're mounting fixed glass panels on a roof, you'll need appropriate mounting brackets for each panel. KickAss has dedicated mounting kits for its fixed glass panel range:
• The KickAss Mounting Kit for Fixed Glass Solar Panels suits the standard glass roof top range and includes everything needed to secure the panel to a vehicle or caravan roof.
• The KickAss Mounting Kit for Ultra Slim Fixed Glass Solar Panels is designed to match the slim 6mm frame of the ultra slim range (available in 80W, 110W, 170W, 210W, and 280W).
• There's also a dedicated mounting kit for the 280W Ultra Slim panel, which has slightly different dimensions to the smaller models.
When mounting multiple panels side by side, plan your layout carefully. You'll want to ensure the panels don't shade each other as the sun moves across the sky, and that cable routing to your branch connectors or controller is as direct as possible.
A Watt Meter (Optional but Highly Recommended)
Once you've got multiple panels wired up, it's incredibly useful to be able to monitor your actual solar input in real time. The KickAss Digital DC Watt Meter lets you see exactly how many watts and amps your array is producing at any given moment. It's simple to install inline between your panels and controller, and it takes the guesswork out of understanding your system's performance.
Step-by-Step: Connecting Two Panels in Parallel
Here's a basic walkthrough of how to connect two identical fixed glass solar panels in parallel to a charge controller:
- Gather your panels, MC4 T-branch connectors, extension cable if needed, and your charge controller.
- Connect the positive (+) MC4 output lead from Panel 1 and the positive lead from Panel 2 into the T-branch female connector (positive side).
- Do the same for the negative (-) leads using the male T-branch connector.
- Run the combined output from the T-branch connectors to your charge controller's solar input terminals – positive to positive, negative to negative.
- Connect your charge controller's battery output terminals to your auxiliary battery.
- If you have a watt meter, install it inline between the T-branch output and the charge controller input.
- Power up and check that your controller is reading the expected input voltage and current.
For series connections, the process is slightly different – you connect the positive of one panel directly to the negative of the next, and then run the free positive and negative ends to your MPPT controller. Refer to your controller's specifications to confirm the maximum input voltage it can handle, and make sure the series voltage of your panels doesn't exceed it.
Portable Panels: Connecting Folding Panels and Solar Blankets
Multi-panel setups aren't limited to fixed rooftop installations. If you run portable folding panels or solar blankets, you can connect multiple units together just as effectively.
The KickAss range of folding portable panels are all designed to work with standard Anderson connectors, making it easy to combine them using Anderson Y-splitter cables or appropriate branch connectors.
A few tips for portable multi-panel setups:
- Position all panels to face the same direction and at the same angle. Inconsistent positioning reduces the benefit of having multiple panels.
- Ensure your charge controller is rated for the combined output of all panels. If you're combining a 120W and a 160W blanket, for example, that's 280W going through your controller.
- Keep cable runs as short as practical to minimise voltage drop.
- The newer KickAss DC solar blankets (120W and 200W) use TOPCon cell technology and include both Anderson and USB outputs – they can also be used standalone for direct device charging without a controller.
A Note on Controller Ratings and System Sizing
One of the most common mistakes when connecting multiple panels is underrating the charge controller. Every watt you generate needs to pass through it, and a controller running at its absolute maximum will either throttle your input or – worse – fail early.
As a rule of thumb:
- For a 12V system, divide your total panel wattage by 12 to get the approximate maximum amps, then add at least 20 to 25 per cent as a buffer.
- Two 170W panels = 340W. 340 / 12 = 28.3A. A 40A controller gives you comfortable headroom.
- Three 110W ultra slim panels = 330W. Same result – a 40A MPPT controller is the right call.
Ready to Upgrade Your Solar Setup?
Connecting multiple solar panels is one of the most impactful upgrades you can make to a 12V camping or caravan system. Whether you're doubling up a pair of fixed glass panels on the roof, running two folding panels at camp, or building out a serious off-grid array, the principles are the same: match your panels, choose the right wiring method, size your controller properly, and use quality components throughout.
You can browse the full range of KickAss solar panels and solar accessories online, or drop into one of our retail stores to get hands-on with the products and chat to our 12V experts.