Do I need a battery with solar panels?
For most things you plug in, yes. A solar panel makes electricity only while light falls on it, and the amount changes with every cloud. Most devices want steady power, so something has to store the energy and smooth it out. A portable power station does that, which is why panels and power stations are sold together.
What panels can and can't do on their own
- Panels can't store energy. At night, or in heavy cloud, there is nothing to draw on.
- Output isn't steady. Voltage and power swing with the light, and most devices and chargers can't cope with that directly.
- Some simple loads can run straight from a panel, such as a small fan or a purpose-built 12 V device, but that is the exception.
What the power station adds
- A charge controller (often an MPPT type) that takes whatever the panel is producing and charges the battery safely.
- A battery that stores the energy for the evening and for cloudy days.
- An inverter that gives you steady 230 V mains, or USB and 12 V outputs, whatever the weather.
The unit's solar input limits are covered in matching panels to your power station.
Do solar panels work in a power cut?
This is a common question from people with solar panels on their roof, and the answer surprises many. A standard grid-connected house solar system is designed to shut down when the grid fails, as a safety measure, so it doesn't feed power into lines that engineers may be working on. UK installers and energy sites make the same point: your panels can be in full sun and still go quiet in a blackout unless the system includes battery storage set up with backup. See, for example, advice from Switch Together and Heatable.
A portable power station is a separate, plug-in way to have power in a cut. It isn't wired into your house, so don't connect it to your home's circuits, and ask a qualified installer or electrician about any fixed backup system. For what to plug in, see what a power station can run in a power cut.
When panels without a separate battery make sense
- You only run things in the daytime, and they tolerate changing power.
- The panels are part of a purpose-built system with its own controller and storage, such as a fixed van or cabin installation put in by a professional.
For portable camping, van and power cut use, a power station with panels is the simpler route.
How big should the battery be?
It depends on what you run and for how long. Use how many solar panels do I need? to size the panels, and the power sizer to size the battery and panels together.