The sun is a near-unlimited source of free electricity, which makes the idea of using a solar car battery charger so tempting. If you need to charge your car’s battery, 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 2024 at a glance:
Best solar battery charger: AA 12V Car Solar Battery Charger 4.8W – View offer on Amazon UK
Editor’s pick: CTEK CS FREE – View offer on Amazon UK
Best solar battery charger on a budget: Eco Worthy 12V Portable 10W Solar Battery Maintainer – View offer on Amazon UK
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.
The best solar car battery charger 2024
The best solar car battery charger
Both connections will ensure that the car is being charged whenever there's sunlight as both connections bypass the ignition, a required source for other solar battery chargers (like a 12v socket). Beyond this, the large area of the charger will ensure a healthy battery remains topped up, although the AA don't recommend using this on a dead battery.
Pros
- Works without an ignition source, which will help some
- Represents good value for money at around £40
- Includes several connection ports which increases its versatility
Cons
- No weather resistance, which limits its capabilities
- Isn't useful for dead batteries, rather maintaining live ones
| Dimensions | 34.5 x 44 x 6.2cm |
| Weight | 2.2kg |
| Watts | 4.8W |
| Connects to | EOBD port, battery clamps |
Editor's pick
Rrp: $199.95
Rrp: $199.95
This technology works by working out the safest way to revive a dead battery, within 15 minutes of being connected. This is a pretty extreme example of a solar battery charger, but it is well worth considering.
Pros
- Can restart totally dead batteries, which makes it double as a jump starter
- Utilises intelligent trickle charging to maximise charging efficiency and battery conditioning health
- Is an incredibly useful device to have as a power bank on camping trips
Cons
- Requires two separate pieces to become solar-powered, which adds up a pretty huge cost
| Dimensions | 24.9 x 9.9 x 7.9 cm |
| Weight | 1.36 kg |
| Watts | N/A |
| Connects to | Battery clamps |
The best solar panel for charging a CTEK unit
A CS Free is useful to take to the campsite thanks to its great power bank capabilities, and topping up the power using the sun is the most eco-friendly way you can go about it.
Pros
- A very eco-friendly method of charging up your CS Free power bank
- Good quality, premium materials as per CTEK products
- You can take it as well as the CS Free anywhere on camping trips
Cons
- Doesn't represent as good value (for both the panel and charger) as the rest
The best budget solar charger
The blocking diode included ensures that there's no chance of the solar panel discharging the battery and the solar panel is very versatile, affixing to a car in a number of ways. There's a soft, padded rear perfect for use on your dashboard without the fear of leaving scratches, suction cups for mounting to glass and a strip that can attach it to the back of a sun visor.
Pros
- Good amount of power (10W) for the price of just £30
- Easy to mount on a car, thanks to suction mounts
- Suitable for a wide range of vehicles from cars, motorcycles, and boats
Cons
- No OBD connector, which limits its capabilities
| Dimensions | 28 x 26 x 0.25cm |
| Weight | 320g |
| Watts | 10 |
| Connects to | 12V socket, battery clamps |
The best solar battery charger for use over long periods
With 6W, its power output is ideal for trickle charging. It connects either via a 12V socket or battery clamp and while it's not the most technologically impressive option, it does work very effectively over a long period.
Pros
- Keeps your battery topped up with ease for a longer period of time
- Easy to use, thanks to either crocodile clips or a 12V socket
- Maintains steady power at 7.5W, which is perfect for many vehicles
Cons
- Not as powerful as some may want - others can offer up to 10W
| Dimensions | 29.5 x 29.5 x 3cm |
| Weight | 1.1kg |
| Watts | 6W |
| Connects to | 12V socket, battery clamps |
Best for maintaining charge
You can also get 1.5W and 2.4W versions at lower prices, but the top model is our favourite due to its capabilities across a range of different vehicles. It's simple clip-on and setup method makes it easy to use as well.
Pros
- Easy to set up, thanks to simple clips and sockets
- Power output of 4.8W, whch should be enough for a wide range of vehicles from cars to motorcycles
- Other, less powerful versions available with 1.5 and 2.4W respectively
Cons
- Lower power output than others, which may not be suitable for more powerful vehicles
| Dimensions | 35x 12.5 x N/Acm |
| Weight | 0.5kg |
| Watts | 1.5W |
| Connects to | 12V socket, battery clamps |
Most versatile solar battery charger
In theory, you could stick this charger on the windscreen of your vehicle or on your garage wall, close to your battery terminals. It comes with a 12-month warranty and had three indicators reflecting its status. It can even prevent over-charging like a smart battery charger.
Pros
- Prevents over-charging of the battery
- Easy to use, thanks to light indicators
- Comes in different guises, depending on your needs
Cons
- Quality isn't as great as others, but is reflected in the price point
Best solar panel trickle charger
It can be used for a variety of applications but is an overall perfect device for gently trickle charging your vehicle's battery, whether it's a car, motorcycle, or boat.
Pros
- Easy to use and has a variety of applications
- Good build quality, as per Ring Automotive products
- Easy to store away, thanks to weight and dimensions
Cons
- Not as powerful as others
Solar car battery charger FAQs
Do solar car battery chargers really work?
Yes, solar car battery chargers do work, 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.
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 Battery Tender, NOCO, and Sunway Solar, which offer a range of products to suit different needs and budgets. The AA 12 V Car Solar Battery Trickle Charger, which is our Editor’s choice, is a pretty good all-rounder at a decent price.
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 a solar battery charger?
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 do I install a solar battery charger?
If you’re wanting to use a solar battery charger the first thing to remember is to turn your engine off before plugging the solar car battery charger in.
If you’re connecting your solar car battery charger to your OBD or 12V socket then the best place to place the panel is on the dashboard because it’ll capture the most amount of light and the charger will reach the sockets. Remember that not all 12V sockets work without the ignition on, which would render the solar car battery charger useless unless you could leave the keys in (a very bad idea).
If you’re connecting a solar car battery charger directly to your engine, you’ll need to leave your bonnet open for the solar panels to work.
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.
How we choose the best solar battery chargers
All of these solar car battery chargers have been hand-selected by our team of experts who have spent hours investigating and researching solar car battery chargers to make it easier for you to find the very best, and we’d never recommend a product we don’t believe in.
Where possible, we also test and share the latest and best products you should know about.
Ryan Gilmore is the Deputy Autos and Tools Editor for Parkers, specialising in car cleaning and hand tools. A veteran car cleaner; if it details, waxes or washes he’ll be on hand to make sure it’s worth your money.
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