Having solar panels on a van or RV is the best way to generate off-grid electricity.
It allows you to head out into the world without the need for a mains hook up or to recharge your batteries by driving around.
The annoying thing is the limitations on how much energy you can produce.
There’s limited roof space to mount solar panels and you might end up parked in a shaded area.
The solution?
Add a portable solar panel to your existing system!
If you have a question about this, then you’re not alone, it’s a common thought.
And the good news is that it’s very easy to do.
Keep reading to find out how to add a portable solar panel, plus the factors to consider before attempting the hookup.
How to Add a Portable Solar Panel to an Existing System
You’ll need a few components to hook up your portable solar panel. You might find you can buy complete kits or you can simply buy the parts individually to suit your needs.
What you’ll need:
- Portable solar panel
- Solar Charge Controller (A second one specifically for your portable solar panel)
- Solar panel cables (MC4 adaptors)
- Battery cables
The easiest way to connect your existing system and the portable panel is with a charge controller connected directly to your battery.
Step 1 – Connect Charge Controller to Battery
To avoid problems with compatibility it is best to get a second solar charge controller to work directly with your portable panel. Generally, you will want to avoid connecting to your existing solar panels and charge controller.
- Find the positive and negative battery terminals where your exiting system is connected. You will be connecting directly to the battery terminals.
- With your new charge controller, connect the positive (red) battery cable directly to the positive terminal on the charge controller and battery.
- Repeat this with the negative (black) battery cable.
Always connect your solar charger to the battery first.
Step 2 – Connect Solar Panel to Charge Controller
Portable solar panels can have many different connections. Often they still have traditional MC4 connectors which make it easier to match with your charge controller.
- Using MC4 adaptors connect the positive wire to the positive input on the solar charge controller.
- Connect the negative wire in the same way
- The portable panel can now charge the battery without interfering with the other solar panels. (A bit like filling a pool with two hoses.)
Step 3 – Place in the Sun
With your equipment safely connected to your battery, you can place the solar panel in the sun. Here are some tips for best usage:
- For best performance, angle it at 30 degrees toward the sun.
- Make sure your cables don’t create a trip hazard.
- Strong wind can knock your solar panel over.
- Avoid liquid and rain as portable solar panels are not always waterproof.
Can You Connect a Portable Solar Panel Directly to Existing Panels?
You might be thinking of connecting your portable panel directly to your existing solar panels or charge controller.
Generally, it is best to avoid this as it presents a number of compatibility issues. It is bad to mix different types of solar panels with varying power, voltage, and cell structure. The difference in electric output can damage the equipment.
Adding to this, your original charge controller will be sized to work with a specific current. Trying to push extra current through it could create an overload.
The easiest thing to do is to run separate systems directly to your battery.
Final Words on Adding a Portable Solar Panel
It’s super useful to have the option of using a portable solar panel to charge your van or RV battery.
When you’re parked up you can get extra charging power by placing it in direct sunlight.
Plus you can quickly pack it away and store it safely when driving.
Rather than interfere with your existing system, your best bet is to simply connect directly to your battery to give it a boost.
Portable solar panels come in various shapes and sizes, you’ll find all sorts of connections on them. So check out what you need, such as a controller and adaptors, to hook up to your battery.
Thinking about permanent additions? Read my guide to Adding a Solar Panels to an Existing System: Is it worth it?
