The sun is a near-unlimited source of free electricity, which makes the idea of using solar car battery chargers so tempting. If you need to charge your car’s battery but don’t want to plug in a traditional car battery charger, one of these clever solar panels on your dashboard can supplement battery life, preventing a flat battery.
This idea used to be reserved for particularly eco-minded vehicles, but now there are a raft of aftermarket examples available. These inexpensive slabs of cells will happily sit on a car’s dashboard or rest on the bonnet, collecting energy from the sun to provide some extra electricity for a car’s battery.
They work similarly to a trickle charger, albeit without needing a socket to plug the device into. They’re great for driveway-parked cars that aren’t driven often and are at risk of a flat battery without some extra support.
The best solar car battery charger 2025 at a glance
It would, in an ideal world, be quite nice if our favourite battery chargers from CTEK or NOCO could be solar powered. But as that’s not very possible at the moment, this is the next best thing and should at the very least prevent a flat car battery. We’ve found the best for you and listed them below.
How we test: solar car battery chargers
Each of these solar car battery chargers was tested on a set of parked-up cars left at Parkers HQ for a number of weeks. These consisted of a 1983 Audi 80, a 2010 Mazda MX5, and a 2001 Ford Puma.
Each one had battery-related difficulties throughout our test, and we acted accordingly over a period of a few weeks to ensure we had a fair test. For instance, the Ford’s battery was a lot lower than it should’ve been for the assigned solar panel to be effective. We also found in our tests that after connecting them via the 12V/cigarette lighter alone (if the unit was provided with them), it drained the batteries flat after checking up on them a week later. It was after we boosted each of the batteries and connected them via the panels’ provided crocodile clamps, that charging would become effective.
Each of the solar chargers was kindly provided by the manufacturers, and additionally to those that we have tested, we’ve also included a couple of recommendations as alternatives, using our in-depth research and knowledge from the testing we conducted.
What we look for in solar car battery chargers
In each of these individual tests, we’re primarily looking for charging capability as this will be the number-one thing on a buyer’s mind. Is the solar panel good enough to be able to keep a car’s battery topped up? That’s ultimately what we set out to answer in our test.
Next up, we’re looking for ease of use. If a charging unit comes with a set of complex instructions or is a bit of a faff to set up, it will be deducted some points. Ideally, you want to be able to just plug in the solar charger and let it do its thing – so you can come back to the vehicle without a flat battery.
Value for money is also considered. These units aren’t cheap sometimes, so it helps to know if you’ll be getting your money’s worth with these solar battery chargers. This will eventually be tied in with the overall score, which will determine how well we rate them.
The best solar car battery chargers 2025
Tested product
The best solar battery charger
The Ford Puma test vehicle we tried the charger on was parked up for quite a while - which isn't ideal for solar charging conditions. However, we did hook it up and checked back on it within the space of a week and a half. Sure enough, the car didn't fire up, so we suspected the battery needed a proper charge before testing out the device in its proper form.
Unbelievably however, two-ish weeks later when I approached the vehicle ready with a battery charger, I disconnected the clamps of the RSP1000, turned the key, and the little Ford fired right up without a fuss. Clearly therefore, the Ring unit managed to provide enough charge from dead to a hassle-free start-up.
I found this to be an amazement in terms of performance, and because of that, it sits as the one solar charging panel I would opt for if I was looking to buy one. It's a shame it doesn't have suction mounts, but the capabilities of this panel does override that for me.
Review by Aaron Hussain
Pros
- Was able to give the battery enough of a recharge to start on our test
- Materials feel good-quality and the terminal clamp wires are long enough to reach a lot of batteries
- Perfect for a number of applications, including cars, campervans and boats
Cons
- No suction cups or anything secure to place it on
| Power | 10W |
| Dimensions | 37 x 23.5 x 2.5cm |
| Weight | 1.34kg |
| Connection type | Terminal clamps, 12V socket |
Tested product
Editor's pick
The main source of concern I have with the CS FREE isn't the device itself, but rather leaving it outside on display. You can't realistically place it inside like the other options, so leaving it to charge on the street or open driveway would risk getting the equipment stolen. This of course, isn't an issue if your vehicle is parked up in a secure spot while having access to the sun.
Setting it up isn't the easiest task in the world, either. But once you get the hang of it, it's a bit of a lifesaver for giving a battery a bit of charge, so you can connect up a solar panel. I used it on the Audi 80, which gave it enough charge so that the Sealey unit could keep it topped up.
Because of its power storage and power bank outlets, it can be a useful device for camping as well. For charging up devices or even powering something else, the usefulness of the CS FREE is rather limitless.
Review by Aaron Hussain
Pros
- Is a very versatile item with loads of different uses and capabilities
- Connects up to 60W solar panel for sun-powered charging
- Is also a very effective power bank for camping trips
Cons
- The charger and panel need to be purchased together
| Power | 120A/h |
| Dimensions | 24.9 x 9.9 x 7.9 cm |
| Weight | 1.36kg |
| Connection type | Battery clamps |
Tested product
Editor's pick
In terms of usability, the solar panel is slightly complex at first. You get this rather tall bag, which acts as its stand and comes with a couple of hooks to attach the panel to. It is a bit fiddly at first, and it certainly took me a few tries to get it positioned correctly.
I can imagine it'll serve you very well if you're planning on going camping. It can provide a great source of power maintenance for a campervan or the accessories you bring with it. For a car, it's a little more complicated, but if you have the means to leave it parked up in a safe driveway with plenty of light, it's a useful bit of kit if you want to avoid using mains electricity.
Perhaps the main reason why it commands such a price increase over others is the fact it can help the CS FREE charge at up to 60W. This is almost comparable to what a plugged-in conventional CTEK charger can manage, so to see such figures in solar panel form is especially impressive.
Clearly then, it's incomparable to any other solar-powered battery charger on sale. But the power and uses - even away from cars - you can use it for makes the CTEK setup my personal choice if I was after a solar charging kit.
Review by Aaron Hussain
Pros
- Has 60W worth of power, which is substantial compared to others
- Fabulous quality and materials that make it feel premium
- Ideal for a number of applications, other than car charging
Cons
- Is very bulky and large to carry around
- You don't want to leave it unattended, due to its value
| Power | 60W |
| Dimensions | 42.2 x 53.6 x 2cm |
| Weight | 4kg |
| Connection type | Terminal clamps |
Tested product
Best solar battery charger for top-ups
We had a bit of trouble initially. As it turns out, you can't connect the panel by using the cigarette lighter, because the battery will run flat. It was only after I charged it back up with a battery booster and connected the panel using the terminal clamps, was any battery maintenance achieved.
I'm quite happy to report that days after leaving the car alone a second time, it fired right up again. It's designed to keep a healthy battery charged up rather than act as a conventional battery charger that can recharge a dead unit. And provided that the Audi was facing the sun - which it conveniently was - it could be kept up to good health with ease.
I like the Sealey a lot; it's a nice little unit to keep the battery of a classic car topped up, should you have to leave it outside periodically. It has a tiny amount of power output, but in the right conditions, it works very neatly.
Review by Aaron Hussain
Pros
- Ideal for batteries on older vehicles
- Good quality and materials for the price point
- Will keep a battery topped-up with ease, provided it has enough charge already
Cons
- At 2.4W, it certainly lacks in power, although you can opt for more powerful versions
| Dimensions | 37 x 21cm |
| Weight | 1.26kg |
| Watts | 2.4W |
| Connection type | Terminal clamps |
Recommended product
The best value solar battery charger
It comes with a handy set of suction cups, crocodile clips, and can be placed pretty much anywhere, so long as it's facing the sun. It's roughly the same size as the others that we tested, so you shouldn't have much trouble installing it on an average car windscreen.
Pros
- Easy to install, thanks to suction cup mounts
- Good value for money, sitting at around the £30 mark
- Perfect or uses in cars, boats, caravans and more
Cons
- Don't expect to rely on it completely to recharge a 12V battery
| Power | 10W |
| Dimensions | 26 x 28 x 1.2cm |
| Weight | 0.54kg |
| Connection type | Terminal clamps |
Recommended product
The most versatile solar battery charger
There's even a little LED light on the side of the unit, which can tell you when the vehicle you're charging is ready to be used. In terms of power, it's a 4.5W unit, so it should provide a decent top-up trickle charge for a vehicle parked directly in the sun.
Pros
- Easy to set up, thanks to suction mounts and terminals clamps
- Compact enough to fit in a lot of cars
- Is very capable, boasting 4.5W of power
Cons
- Not the most powerful solar charger available.
| Power | 4.5W |
| Dimensions | 34.5 x 21cm |
| Weight | 1.1kg |
| Connection type | Terminal clamps |
Solar car battery chargers: FAQs
Are solar car battery chargers any good?
They only work under a specific set of criteria and conditions. But once you have those in check, they are useful units for keeping your battery maintained while its parked up for days or weeks at a time in a place where sunshine can reach it.
It should be noted that they are not designed to recharge a dead or low battery, as they simply don’t have the power capacity to do so. The best use for them is to keep a battery topped up on charge as very little electrical current is being fed to them compared with a more conventional, plug-in smart battery charger.
Can a solar panel charge a car battery?
Yes, solar car battery chargers do charge car batteries, but their effectiveness depends on a few factors, including the quality of the charger, the size and condition of the battery, and the amount of sunlight available.
The best use case is keeping an already-charged car battery topped up. This is, for example, if you’re leaving it outside without driving it for perhaps 1 to 2 weeks at a time and simply want to keep it fresh for the next time you get into it. The same principle also applies to boats, caravans, and more.
They shouldn’t be seen as a replacement for a conventional battery charger. They’re not designed to recharge batteries from dead, and for that task, you’re going to need a smart battery or trickle charger.
What is the best solar charger for a car?
That will depend on a number of factors, including budget, type of use (such as maintaining a charge versus recharging a depleted battery), the size of the car battery, and the amount of sunlight available in your area. Popular choices often include brands like Ring Automotive, Sealey, and CTEK, like the examples we’ve tested.
How do you use a car battery charger?
Typically, whether it’s a budget battery charger or a more advanced unit, you simply plug it into a socket, hook up the crocodile clamps to the battery terminals, and set your device to the correct setting. Afterwards, you simply leave it and let it do the rest, whether your battery needs charging or you just want to keep it maintained throughout a period of time.
With solar panels, the best way to use them falls more in the latter category. They’re designed to keep 12V batteries topped up while a vehicle is parked up under plenty of sunlight. To use such a device, you have to make sure your car’s battery is in good health beforehand, and then, you can hook it up accordingly to ensure you maintain a high charge.
Can you overcharge a car battery with a solar charger?
Theoretically, it is possible to overcharge a car battery with a solar charger if the charger does not have a built-in charge controller or overcharge protection. The majority of good solar chargers typically include a charge controller to regulate the charging process and prevent overcharging. This ensures the battery remains at an optimal charge level, protecting it from damage and extending its lifespan. Always go for a charger with overcharge protection to avoid battery damage.
What features should I look for in solar car battery chargers?
Think about what needs you have for your car. If you just want to keep it topped up then a simple trickle charger with a low wattage should be fine. If you have a car with a very large engine or one that drains the battery very quickly then it may be an idea to invest in a portable jump starter to get your engine revving once more.
Try and find a solar car battery charger that has an OBD option. Modern cars come with one and it’ll make trickle charging a lot easier as this socket works regardless of whether there is a source of ignition.
How to install a solar battery charger
Installing a solar battery charger is somewhat more straightforward than hooking up a conventional battery charger. Firstly, you must ensure you have the engine turned off and have enough charge in the battery for the solar panel to effectively work.
They’re not designed to recharge flat batteries – rather just maintaining them by keeping the charge topped up from an already-healthy level. If your unit has suction cup mounts, it’s a good idea to stick the unit onto the inside of the windscreen and feed the terminal clamp wires through the door and bonnet gaps to the battery’s location.
By that point, the solar charger should do its task by keeping the battery in check. You do need to ensure that your vehicle is parked in a position where it’s facing a good amount of sunlight. That way, it’ll work at its most effective at providing power to your vehicle.
Are solar battery chargers worth it?
It depends on your needs. As per the name, solar battery chargers need the sun to be able to work properly, and if you can’t get the sun towards your unit, it’s going to be pretty useless. However, if you have a certain situation where your car is kept outside or can let a lot of light in through a garage window, then they can prove to be pretty effective.
They’re especially useful if you want to keep your electric bills at a minimum. Even with the CTEK CS Free, if you use the solar panel to charge that, you have a wireless method of multiple things from providing charge to a dead car’s battery, acting as a power bank for a camping trip, and quite a few more besides.
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