5 Best Solar Car Battery Chargers 2020 [Buying Guide]

5 Best Solar Car Battery Chargers 2020 [Buying Guide]

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.  It converts light energy from the sun into 12v DC electricity which is then transported through a lead wire and connection.  It is important to note that this is a trickle charger to keep an already charged battery topped up.  It charges Wet, Gel, SLA, AGM and Deep cycle batteries.  Trickle chargers are mostly below 5 watts and will not need a charge controller for a battery whose capacity is 20Ah or greater. For those below you might to purchase one that has overcharge protection or you can purchase a charge controller alongside the charger.

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Best OverallBest ValueHonorable Mention
Preview
ProductSUNER POWER 6W
12V Solar Car Battery Charger
ECO-WORTHY
12V Solar Car Battery Charger
Sunway 5W
12V Solar Car Battery Charger
Wattage Available (W)2.4W, 6W, 8W, 12W, 14W5W, 7.5W, 10W1.5W,4W,5W,8W
Overcharge ProtectionYesNoNo, charge regulator sold separately
LED indicatorYesYesYes
WaterproofWeatherproof NoYes
Price

Advantages of a Solar Car Battery Charger

Works with Solar

The sun a free source of energy that can be accessed almost everywhere.  It is also a clean form of renewable energy making this device environment friendly.

Lightweight and Portable

Averaging at pounds you can easily carry it and mount it.

Easy to install and use

You can easily mount with suction cups or screws and has easy to use plug and play connection that can be used with the car’s cigarette lighter.

Low maintenance

You will just need to wipe the Solar panel once a month.

Choosing the Best Solar Car Battery Charger

This is what we looked when choosing the solar charger.

Easy Mounting

Suction cups that allow easy mounting on the cars dashboard.

Solar Panel on Car Dashboard
Solar Panel Mounted on Windscreen with Suction Cups

Efficiency rate

Solar panels that allow for charging in low light and cloudy conditions.

Covered in tempered solar glass

This allows for better protection

Interchangeable clamps and Cigarette Cable

The charger should come with a connection cable, cigarette lighter and bare connector.

LED

An LED light that indicates flow of current is a feature that enables you to know whether the charger will charge your battery.  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.

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.

Best Solar Car Battery Chargers

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 Car Battery Charger & Maintainer

Advantages

Small size allows it to be used on the go.

Weatherproof

Disadvantages

Not waterproof

The top spot we have given to SUNER POWER 12V Solar Car Battery Charger. And for good reason the small compact good quality solar trickle 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. It also comes with suction cups, screws and anchors for mounting.  It comes with a plug and play connector (2.4m cable (3 pcs of 0.5m connection cable, cigarette lighter and bare connector). It can connect via the cigarette lighter or using the long cable you can connect the charger to the battery terminals using the clamps.   It has a small LED light that lights up when the panel is receiving power. It has a built-in diode to prevent it from draining your battery.

  1. Sunway Solar Car Battery Trickle Charger

Advantages

Waterproof

Doesn’t need direct sunlight

Disadvantages

Plastic casing can break

Not waterproof

The Sunway Solar Charger 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. 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.

  1. SOLPERK 12V Solar Panel Solar trickle Charger

Advantages

Works in any weather

Waterproof

Disadvantages

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

  1. ECO-WORTHY Solar Panel Battery Charger

Advantages

Cost

Works even in cloudy days

Disadvantages

Needs constant wiping as it gathers dust easily

At number 4 we have the ECO-WORTHY Solar Panel Battery Charger Although this is the budget option it is well designed and made.  It comes with adapters to both charges the battery through direct through the alligator clips or through the cigarette lighter outlet.  It also has an LED to assure you that it is charging.  It has a blocking diode to prevent reverse charging.  Can be used for Car, Boat, RV and lawnmower.

  1. ALLPOWERS 18V 5 Watts Solar Car Battery Charger

Advantages

Small size

High Voltage

Disadvantages

Not waterproof

Needs direct sunlight

Last and not least is the ALLPOWERS 18V 5 Watts Portable Solar Panel Charger. Small sized high efficient mono Crystalline Solar panel. It has blocking diode to prevent reverse charging.  It has a green LED indicator to show when it is receiving charge.  It is easy to install, easy to use and maintenance free.  It comes with a  car charger cigarette lighter plug(power cord 1.5m) and a Battery charging clip line(power cord 1.5m) and 4 Suction cups.

How to use a Solar Car Battery Charger

You’ll need to mount the Solar Panel where there is sunlight. The can easily place the panel on your car’s dashboard inside the car. However if you have tinted windows this can have an impact on the amount on sunlight reaching the panel and may not charge.  You can easily mount on your windshield using the suction cup. If the car is indoors you will need to mount the panel outside. The panel should come with screws that allow for that. You can also mount it on top of your car.

Solar Panel Mounted on Top of a Car

You then either Connect the one way quick to the cigarette lighter or connect the solar panel directly to the cigarette lighter socket. Plug and Play connector connects to the cigarette lighter or Alligator clip. Make sure the lighter socket is live. (Test with the phone charger). This however may not work if the cigarette lighter does not operate when the ignition is powered off in this case use the battery clamps directly on your battery. The alligator clip adapter is connected directly to the car battery. Red is positive and blue is negative. Be careful and ensure to separate the clamps to avoid collusion. This can produce a short circuit.

Trickle Charging

Solar Car Battery Chargers  utilize the trickle effect to charge the Battery. In essence, this means that the battery is charged at a similar rate to that at which it uses energy (its discharge rate), to maintain full charge, whilst also taking a measure of protection against overcharging and damaging the battery.

Some earlier types chargers will continue to charge the battery whether or not the battery is fully charged. This means that care needs to be taken on the part of the owner in order to avoid causing damage to the battery. A slight variation was developed with the float method of charging. This type of automobile battery charger features circuitry that helps to prevent the battery from overcharging. It does this by sensing when the battery is nearing the correct ‘float level’, and temporarily stops charging. If the automobile battery remains connected to the charger, charging will resume once the device detects a fall in the float level of the battery. This method ensures that the battery will never be overcharged. Indeed, a float charger may be left connected to an automobile battery indefinitely without causing any damage.

Frequently Asked Questions

Does a it work with Lithium batteries?

No, it does not work with lithium batteries

How long does it take to recharge a 12v battery

A solar battery charger maintains a battery at current charge. It only charges the battery at the draining rate. This is not recommended for batteries below 60%. It could be months before the Battery is fully charger.

When should it be used?

One of the best applications for a trickle automobile battery charger is if you own a second (or third) vehicle that you rarely use. In many cases, automobile batteries will discharge even if they are not in use, and it can often be that you come to use the vehicle only to find that it has a flat battery. To avoid this situation, a trickle or float charger is perfect as, if used correctly, they will ensure that the battery on your vehicle will remain charged and at an optimum level for when you do need to drive it.

What should you be careful of?

The main problem with this type of automobile battery charger is that it doesn’t have any ‘smart’ capabilities. All though float chargers are capable of detecting the battery level, they can’t tell you whether or not the battery is damaged, meaning that you could spend ages charging your automobile battery, only to find that it can’t hold a charge and still doesn’t work. With a trickle type automobile battery charger, you also need to be aware of overcharging the battery. This means that you will need to carefully oversee the charging process to avoid causing any damage or leaks to the battery. However, a trickle type charger is fine for most uses, and is often the cheapest type of automobile battery charger, so should certainly be in your consideration.

If Lighter socket is on that means that the car is on and the battery is already charging.

Yes in this case use clips directly on the battery.

Can I leave it plugged in when driving?

No, you must disconnect the charger from your cigarette lighter or battery when starting engine driving to prevent electrical surge that will damage the panel. You might get lucky once or twice but really there is no need to risk.

Would it drain my battery at night?

No it has a blocking diode that prevents back charging

Will it overcharge my battery?s

If the battery is less than 20Ah you would need a controller other most car batteries are well above 20Ah and will not overcharge.

How does an Automotive Battery Work?

As with any battery, an automobile battery generates energy from a chemical reaction. Within the battery, plates of lead and plates of lead oxide are contained in a solution of water and sulphuric acid. The chemicals then produce electricity, which can be transferred to wires to turn on the vehicle’s lights and begin the ignition process. The acid in the solution responds to the lead plates, which causes the lead oxide to become lead sulphate. When the battery is recharged by an automobile battery charger, the chemical process is reversed, and the lead sulphate returns back to the form of lead and lead oxide. Every time the battery is discharged and recharged, this chemical process is repeated.

During the operation of the vehicle, the battery plays an important role. Whilst the engine goes through its initial start-up, the battery is used to start the motor of the vehicle, and will see continued use in order for the ignition system to crank. During normal circumstances, such as daytime driving, the initial electricity from the charging system of the automobile is enough to keep it running. However, in circumstances when the car is using too much electricity because of things such as lights, radio or other features, the battery is discharged.

There are a few different types of batteries. In older cars, water is required to keep the batteries going, as water is lost from the solution through electrolysis. The lead plates of the battery must not be exposed to the air, and remain in the chemical mix. The two most important batteries, and the varieties that you are most likely to find in your automobile are the SLI battery and the deep cycle battery. Deep cycle batteries are designed to produce a high charge for a long period of time, and are frequently used in motor boats. The downside to this battery type is that the high current can’t be produced for heavy loads or hauling duties. The SLI battery has a low charge, and is designed to discharge as little electricity as possible.

Terms Used in Car Batteries

Cold Cranking Amps (CCA) Cold cranking amps (shortened to CCA) is a measure of battery’s starting power. As a metric, it measures some amps a battery can deliver in 30 seconds at a temperature of 0°F. A battery with a large CCA rating is powerful and capable of starting almost any normal engine.

In addition to CCA, some batteries are rated in marine cranking amps (MCA). This is a measure of a battery’s starting power at 32*F.

There’s no “perfect” CCA rating for a battery. However, it’s always important to choose a battery that exceeds the recommended starting power for your engine. Most batteries with a CCA rating of 700 or more can comfortably start almost any small to a mid-sized outboard motor.

Maintenance and Design Older lead acid batteries require maintenance, making them a nuisance to own. New batteries that use AGM (absorbent glass mat) technology require zero maintenance, making them much easier to own and use.

AGM batteries also tend to be leak proof, making them safe to mount in positions that damage conventional batteries. Some high-end batteries are even designed with a watertight seal that allows the batteries to continue operating even if splashed with water.

Reserve Capacity A battery’s reserve capacity is the amount of time required for a fully charged marine battery to drop below 10.5 volts while discharging 25 amps. Like CCA, reserve capacity is often shortened to RC and is measured at the exact temperature of 80°F.

The higher a battery’s reserve capacity, the longer it’s capable of performing. If you have large electrical demands and need to power a lot of equipment, it’s important to choose a battery with a large enough reserve capacity to match or exceed your needs

Date of Manufacture Over time, batteries gradually begin to lose their effectiveness and stop being able to maintain a charge as effectively as they once could. Even if it’s completely new and unused, a battery that’s one year old won’t perform as well as one that was just delivered from the factory