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Best Solar Car Battery Charger with Overcharge Protection

Car Batteries naturally discharge when not in use. This is a small but constant drain that if overlooked it may drain completely and become dead. This reduces the battery lifespan and you will have to jump start the battery to use again. Modern vehicle have upward of 30 body control modules (computer), alarm system immobilizers and lock monitoring. These devices accelerate the drain on your battery.

If you don’t use your car often or leave in the garage too long, you may find a dead battery. A solar car battery charger will charge your battery when not in use and maintain the charge.

Solar chargers quite simply require the suns rays to start charging your batteries and should be positioned in a place where in it can obtain the greatest amount of sunlight. They also give you the chance to charge your car batteries without the having to connect to an external source of power. But because light intensity can change over time and the battery can be fully charge some of protection is necessary

Why you need one with a Charge Controller

Solar Panels over 5 watts (and occasionally the actual 5 watt) need a charge controller to cope with the output, and to stop overcharging your battery. For larger 12v batteries with more than 20Ah this should not be a concern. However if you plan to leave the charger connected for days; this will give you the comfort and confidence to leave it and not worry about it damaging your batteries.

Below we have listed some Chargers for various uses with overcharge protection. But we highly recommend the Suner Power 12v Charger.

Our PicksProductRatingFeatures
Editorial PickSUNER 8W Solar Battery Charger4.1Solar Charger with Three Stage MPPT Controller
Best Budget Trickle ChargerSunway 5watt Solar Trickle Charger4.0Trickle Charger for Truck and RV Battery
Best High Capacity Solar ChargerAllpowers 60 Watt Foldable Solar Panel4.5High Capacity Charger for Phone, Laptop and Car Battery

Other Features of a Good Solar Car Battery Charger

This is what we looked when choosing the solar charger.

Easy Mounting

A Solar Charger must be directed towards sunlight in order to charge. The best placement for a car in the outdoors will be the windscreen. Suction cups that allow easy mounting on the car’s windscreen. You can also just place it on the car’s dashboard if it will have access to light. If you car is not parked in the outdoors ensure you have long cables that allow you to mount it where you can get sufficient sunlight.

Solar Panel Mounted on Windscreen with Suction Cups

Efficiency rate

Solar panels are known to be inefficient this is that they don’t convert so much of the sunlight to electricity. Monocrystalline solar panels allow for charging in low light and cloudy conditions and will give you the best conversion rate of around 21%.

Covered in tempered solar glass

Tempered Solar Glass allows for better protection of the Solar Panel and can protect the solar panel from wear and tear from bad weather conditions. This is espcially important if you will be placing the panel on the outside.

Interchangeable clamps and Cigarette Cable

The charger should come with a connection cable, cigarette lighter and bare connector. Some cars will automatically work when connected to the cigarette lighter port but if that doesn’t work you should be able to use alligator clips to directly connect them to the battery for charging. More on that later in this article.


An LED light that indicates flow of current is a feature that enables you to know whether the charger will charge your battery. This will save you from a lot of disappointment having connected the solar panel to the battery only to find it not charged. If you aim the panel to the sun the LED should turn on to proves it is generating a current.  You can also plug into the lighter socket when the panel to disconnected to check that the socket is live.

Blocking Diode

It is important as the Solar Panel charges the battery that is does not drain the battery at night. A blocking diode prevents reverse charging.

How we tested for reverse charging  

Voltage Reading of a Car Battery on a Multimeter

Using a multimeter set to continuity measure we tested the solar charger.  We did this by connecting the leads via the positive clip to the multimeter.  By doing this you trying to see whether current is flowing towards the solar charger. There was no continuity. When the leads are connected the other way there was continuity (Positive lead to the negative lead).  Meaning there is flow towards the battery.

Although each are good in their own way. We have ranked from number 1 to number to 5 according to the factors listed above.

1. SUNER POWER 12V Solar Charger & Maintainer


Small size allows it to be used on the go.

MPPT Charge controller


Blocking diode to prevent reverse charging

Suction cups plus screws and anchors for mounting


Cannot charge devices like phones and laptops

The top spot we have given to SUNER POWER 12V Solar Car Battery Charger. And for good reason the small compact good quality solar charger to keep you battery topped off in all season.  It is a well durable well-made high efficient crystalline solar panel with a tampered glass around it. The inbuilt MPPT Controller ensures maximum conversion and battery protection.

It also comes with suction cups, screws and anchors for mounting.  The screws and anchors in addition to the 2.4m cable allow for mounting away from the car especially if you car is parked in doors and you need to place the panel where it can get sunlight.

It comes with a plug and play connector (2.4m cable (3 pcs of 0.5m connection cable, cigarette lighter and bare connector). You can connect it to to your battery via the cigarette lighter or using the long cable you can connect the charger to the battery terminals using the clamps.  

2. Sunway Solar Trickle Charger



Doesn’t need direct sunlight



For Batteries that are over 50ah

if you are looking for the budget option then the Sunway Trickle charger is the one to go. It uses  amorphous technology that allows it work in cloudy conditions.  It is covered with clear PV glass and with Durable ABS plastic housing which makes this solar panels charger stronger.

However you should be cautious with this charger as it doesn’t have a charge controller. The overcharge protection only applies to batteries that are over 50ah so make sure to check your car battery rating. Otherwise this is safe to use for most trucks and RVS.

It is low Maintenance and water proof. It has a built-in diode to prevent reverse charging from batteries. It blue light LED indicator to show when charging.

3. Allpowers 60 Watt Foldable Solar Panel


Two USB ports, DC and 12V output

Foldable and portable

Charger for Phone, Laptop and Car battery

Charge Controller



No suction cups for windshield

If you are looking to go solar why not just have 3 in one solar panel without having to buy a different panel for different uses. The Allpowers 60 Watt Foldable Solar Panel is the one for you. This high capacity solar panel will allow you to charge your phone, laptop, power station and even your car battery.  It also a great addition for emergency as it can give you up 6 amps per during sun peak hours or 30 amps a day.  This translates to around 500Wh on 4 hours of direct sunlight per week.

The two USB ports are rated 5V and have an output of 2.4 amps per port. You can charge two devices with these ports. The DC output has a voltage of 18V and an output of 5amps this comes with a variety of connectors compatible with most power stations and laptops.

The 12V output allows you to charge your car battery through the alligator clips. So when camping with your car you won’t worry about being stuck with a dead battery as you can use the panel to charge your battery.

Being a foldable panel it easily folds up to a suitcase allowing for portability and easy storage and it weighs just around 4lbs.

4. Eco-worthy 25 Watt Solar Battery Charger



Works even in cloudy days


Needs constant wiping as it gathers dust easily

The Eco-worthy Solar Panel kit is a Waterproof 25 Watt Solar charger. It also comes with a sturdy design that is dustproof and waterproof.  It comes with plug and play SAE connectors that are easy to install and free of maintenance.

It also comes with a 3A USB Charge controller with an indicator for charging and discharging.  

This also a great starter kit that is easy to install with plug and play cables with a pre-attached cable on the solar panel.

5. Solperk 12V Solar Panel Trickle Charger


Works in any weather



Casing can break in high temperature

The SOLPERK 12V Solar Battery Charger and Maintainer is a High quality amorphous solar car battery charger that uses  thin film technology and it can work in any weather. It comes with 4 suction cups a cigarette lighter plug and a battery charging clip line.

It is weatherproof  and is covered with a  durable ABS plastic case. It has built-in blocking diode to prevent reverse charging and battery reverse discharging. Blue indicator lights up when charging. The product is light and easy to install for inexperienced people

How to Use a Solar Car Battery Charger

Charging your vehicle battery with a solar trickle charger is easy and can even be done on a continuous basis. Just connect the device and leave the solar panel on your car’s dashboard. You will probably forget it is even there. It can be for new or old vehicles, it does not matter. As long as your vehicle has a cigarette lighter and a battery you can use a solar battery charger. You can also use alligator clips to hook on the batteries directly.

You do not need to have special technical abilities in order to use an auto solar charger. It is as simple as these three steps:

  1. Take the charger out of the box
  2. Set the solar system on the dash of your vehicle
  3. Plug the cord into your cigarette lighter

Mount panel on your windscreen where it sources out enough sun rays. Other position it on the dashboard with its suction cups to put it place. You can do this with your car lighter socket. Alternatively if this doesn’t work with your car use a crocodile clip that comes with the charger and connect it directly to the battery. Its panel provides a stable maintenance level charge to your car’s battery to ensure that your battery remains fully charged even if you don’t start your engines daily.

Now, doesn’t that sound simple? Your car battery will receive the energy from the sun through a trickle charging system. That basically means, as the sun hits the solar cell, energy will be transferred to the battery of your car.

You definitely do not need any special skills to hook up your solar charger. It is so simple anyone who can drive can use a solar battery charger.

Owning a this device can be a great way to bring mobile energy with you almost anywhere you go. You can bring the charger in your automobile as you drive along the countryside. They are also great for spending time at the beach or hiking through the wilderness. Having a portable charger powered by the sun can make your travels much easier. Owning an automotive solar charger will prevent you from having to get a battery jumped because the charger will constantly be adding power to your car’s battery.