Complete Guide to the Best Solar Battery Charger of 2021
Over the years, our cars have gained in safety and reliability; however, they still have one weakness – their battery.
If you don’t use your car regularly (every two weeks), you might have already experienced low battery voltage preventing your car from starting. This situation generates a lot of stress as it is, most of the time, unexpected, and we are often left with no other solutions than using a regular wall plug battery charger.
Don’t worry, this stressful experience won’t happen again if you get a solar car battery charger. They are user-friendly devices that will help you to maintain a charged battery at all times.
In our Buyer’s Guide, I will discuss the benefits of having a solar car battery charger compared to a regular charger. I will show you how to wisely choose your solar battery charger and how to use it properly.
Next, you will find the eight best products of 2021 in our review.
We completed our article by an FAQ in which we will be answering all your most common questions about solar car battery chargers.
For a quick overlook at the best products, let’s start with our editor’s pick
- Best Solar Car Battery Charger: Editor’s Top 3 Picks
- Buyer’s Guide to the Best Solar Car Battery Charger
- Review of the 8 Best Solar Car Battery Chargers Of 2021
- 1. SUNER POWER 12V Solar Car Battery Charger and Maintainer
- 2. ALLPOWERS 18V 12V 5W Portable Solar Battery Charger
- 3. Sunway Solar Car Battery Trickle Charger, 4W, 12V
- 4. MOOLSUN 12V, 10W, Solar Battery Charger
- 5. SUAOKI 12V Solar Car Battery Charger 18W
- 6. ECO-WORTHY 25 Watts 12V solar battery charger
- 7. ACOPower 12V 50 Watt portable solar battery charger
- 8. DOKIO 220 Watts Foldable Solar Panel with Charge Controller
- Solar Car Battery Charger: FAQ
- Final Tips
- Best Selling Solar Car Battery Chargers
Best Solar Car Battery Charger: Editor’s Top 3 Picks
We are featuring the best solar car battery chargers of their category, from solar battery maintainers to solar chargers, to fully charge your car battery.
- Best Solar Car Battery Maintainer – SUNER POWER 12V Solar Car Battery Charger and Maintainer
- Best All-Around Solar Car Battery Charger – ECO-WORTHY 25 Watts 12V
- Best Solar Car Battery Charger for Full Charge – DOKIO 220 Watts Foldable Solar Panel with Charge Controller
Buyer’s Guide to the Best Solar Car Battery Charger
You might not be familiar with solar car battery chargers. Don’t worry, we have summarized in our buyer’s guide the most useful information to wisely pick a charger according to your needs.
How Does a Solar Car Battery Charger Work?
If you get a solar car battery charger, here are the three components you will mostly find out of the box:
- Solar panel
- Solar charge controller
- Battery clips
The main component of the system is the solar panel. Solar panels convert energy from the sunlight into electricity.
Car batteries need at least 12V to be charged, and the solar charge controller helps to get the highest output of the solar panel at all times. As our sun is a natural source of energy, it doesn’t shine the same all day long, and its power output needs to be regulated for smooth charging.
Finally, the battery clips connect your solar charger to your car battery.
In the end, a solar car battery charger produces 12V of electricity to charge your battery from the sun.
Don’t forget that solar panels give their best output under full sunlight. If you want to get the most of your solar car battery charger, expose them to full sun, and try to avoid local shade.
What Are the Two Types of Solar Car Battery Chargers?
There are two categories of solar car battery chargers:
- The solar car battery trickle charger or battery maintainer
- The solar car battery charger
Solar trickle chargers help to maintain your battery at a steady state of charge. It prevents your battery from being drained when it is not used, as 12V batteries naturally lose energy over time.
A solar car battery trickle charger will never charge your battery to its full state.
Solar battery chargers in the range of 5W to 20W are all trickle chargers.
Above 25W, they are considered as battery chargers that can fully charge your dead battery.
In our review, we are featuring both solar battery maintainers and solar battery chargers.
What Is the Difference Between a Solar Car Battery Charger and a Regular Car Charger?
The main difference is that a solar car battery charger uses solar energy, a widely available renewable source of energy, to charge your car battery. Solar car battery chargers operate as stand-alone systems.
On the other hand, a regular car charger will need a wall plug connected to a grid electricity to charge your car battery.
The other difference is the charging type – a regular car charger will charge your battery to its full state in a few hours with a current of 16–32 Amps and can then be unplugged.
A solar car battery charger is made to be connected over a long period of time or even permanently as the current provided could be less than 1 Amps.
Their main function is to maintain the battery level to a fully charged state, preventing your battery from being drained even after a long period without use.
Some more powerful solar battery chargers will be able to fully charge your car battery in less than a day.
What Are the Benefits of Solar Car Battery Chargers?
Car batteries naturally discharge over time when not in use – this is called the self-discharge. In addition, modern cars have many built-in electronic systems (alarms, control modules, sensors, etc.) that are permanently getting electricity from the battery.
The main function of a solar car battery charger is to cover the self-discharge and the constant small electricity drain from car electronics.
The main benefits of a solar car battery chargers are:
- Prevent self-discharge of your battery – no more low battery.
- Increase overall battery life duration.
- Limit battery sulfation (main cause of battery degradation).
- User-friendly, plug and play.
- Small and lightweight.
- Extremely durable.
- Will save you money (no need to buy a regular car battery charger).
5 Tips to Choose the Best Solar Car Battery Charger
Now that you know why solar car batteries are the best partners of your car battery. Let’s have a closer look at how to choose them wisely.
As a solar and battery expert, I have selected the most important criteria to consider when choosing a solar car battery charger:
1. Solar Panel Power
As the most important criteria, it will determine your type of solar car battery charger. Below 25W, the power output is not enough to fully charge a battery. On the other hand, it is sufficient to compensate for self-discharge.
Below 25W, you will only find solar car battery trickle chargers, also called battery maintainers. The higher the power of the solar panel, the faster your battery will be charged.
2. Ease of Use
Manipulating car batteries could cause safety problems for nonprofessionals. Luckily, we have selected plug-and-play solar battery chargers that offer both the regular crocodile clips for direct battery connection and the car cigarette socket that allows current to flow in the car battery without opening the car hood.
All the products selected are strongly built and rain-resistant. Their solar panels can last at least 15 years.
In a car, size and weight matter. We made sure that the selected solar chargers are compact and easy to handle.
5. Blocking Diode
It is not the most known feature, but this one is quite important. A blocking diode will prevent reverse discharge during nighttime when your solar charger is not producing electricity.
Review of the 8 Best Solar Car Battery Chargers Of 2021
Our review features both solar car battery maintainers and solar car battery chargers. If you want to know the difference between a maintainer and a charger, have a look here.
SUNER POWER is a young brand specialized in domestic solar power. They are a team of passionate technicians committed to deliver the most advanced and durable solar products.
The SUNER POWER 12V features a 12W solar panel delivering up to 1 Amp under full sun. It will have no problem keeping your battery at its highest state of charge.
It has a built-in blocking diode to prevent reverse charging. It is truly plug and play – just mount it on your front window with its four suction cups, and plug it into your cigarette socket. Your battery is now in charge.
It also gives you the option to use the classical battery clamps for direct battery connection.
Reliable, it is built with high-quality ABS material. Finally, it is compact and will fit in a pouch.
- 12W to maintain all types of 12V batteries
- Plug and play
- Includes a blocking diode to avoid reverse charging
- Cannot fully charge a car battery
- Not waterproof
Highly recommended, it is compact yet powerful enough to maintain any 12V batteries to a full state of charge. As it is plug and play, you don’t need to be a specialist to use it. This product is also a good value for money.
- [Charge Anywhere] The solar charger converts light energy from sun into 12 volt DC electricity and transported to rechargeable batteries. The charger will generate electricity current to trickle...
- [Charger & Maintainer] The product is a solar powered battery charger and maintainer, safely charges and maintains Wet, Gel, SLA, AGM and Deep Cycle batteries, etc. Also, perfect for any cars,...
- [Reverse Protection] The solar charger will not damage or over charge your battery, similarly, built-in blocking diode prevents reverse discharge, make sure no drain of your battery.
ALLPOWERS is a brand dedicated to solar power for the outdoors. Their products range from foldable solar panels to solar power stations. Therefore, when it comes to solar chargers, you can trust them. Let’s have a closer look at their solar car battery charger.
The ALLPOWERS portable solar battery charger features one of the smallest solar panels of our review. With 5W and 18 volts output (max. 0.28 Amps), it is still capable of compensating the natural loss of your battery.
It is easy to handle – just mount it on your side windows with the two suction cups, or fix it to the sun visor with the included back strips.
This product is a plug and play. Connect it to the cigarette socket of your car, and it will provide top-up power to your car battery. It also features a blocking diode to avoid reverse charging.
One of the most unique features is that it is extremely compact (half of an A4-sized paper, 12.6 x 5.0 x 0.12 inches) and weighs only 11.4oz. It will fit in your car storage compartment when not in use.
- Super compact
- The cheapest
- Will maintain your 12V car battery
- Plug and play
- 18 months warranty
- Low power during cloudy/rainy days
- Not waterproof
- Will not fully charge a car battery
A great entry-level product by ALLPOWERS, it is super affordable and will maintain any 12V batteries to a high state of charge. You might want to consider a more powerful model in case of cloudy days.
- ☀️ ALLPOWERS trickle battery charger maintainer can charge 12V batteries with the power of the sun and create 5 watts of energy
- ☀️ Mono-crystalline silicon panel works in all daylight conditions and is weatherproof（rain drop is OK, but not completely waterproof）for added durability
- ☀️ Works with automotive, motorcycle, tractor, boat batteries, car battery and more
Sunway Solar only offers a handful of products, all dedicated to solar car battery chargers. Their 4W model is an Amazon best seller. Let’s see why we like it.
Don’t be fooled by its tiny size. The Sunway Solar car battery trickle charger is able to maintain your car battery’s state of charge at all times by compensating its natural loss. It features a 4W, 15 volts solar panel, capable of producing 0.27 Amps.
Plug and play, install it on your windshield or side windows with the suction cups. Plug it to your cigarette socket, and it will start charging. It has a built-in blocking diode to prevent reverse charging and protection against overcharge.
Strongly built, you can even bring it outdoors (splashproof) to charge any types of 12V batteries thanks to the crocodile clips. It comes with a 12-month warranty.
It will easily fit in a pouch or car storage compartments, as it is only 13.9 x 5 x 0.5 in and 22.4 oz.
Finally it is affordable to all.
- Good pricing
- Will compensate natural battery power loss
- Plug and play
- 12 months warranty
- Protected against overcharge
- Not waterproof
- Might be limited during cloudy days
This model is tiny and reliable. The Sunway Solar battery charger will maintain your battery. It is one of the best entry models, and it offers the most common features for years of good services.
- [Solar Panel Power Up To 4W]--Keep your 12 Volt batteries topped off with this solar battery trickle charger ,which helps to manage 12v battery drain in all seasons. Designed to compensate for small,...
- [Simple And Very Easy to Use]--This solar trickle charger will NOT overcharge the battery or cause any damage if the battery capacity is 20Ah or greater, .The solar charger panel mounts easily to the...
- [Stronger and Durable]--This solar powered battery charger is Covered with ultra clear PV glass which is more efficient and also with Durable ABS plastic housing which makes this solar panels charger...
MOOLSUN has more than 10 years of expertise in manufacturing portable solar panels. Their team of solar engineers is committed to develop the most advanced solar products. Let’s see below why their solar car battery charger is one of our favorites.
MOOLSUN solar battery charger features a 10 W, 18 V (0.5 Amps) solar panel protected by a splashproof robust canvas.
It is slim and lightweight (15.6 x 6.9 in, 0.86 Lbs). You can fix it to your front or side windows, thanks to the suction cups, or at the back of the rear view mirror with the built-in straps.
It is powerful enough to maintain your battery even during cloudy days. Furthermore, it is user-friendly, and you don’t need to be a battery specialist to use it. Just plug it to your cigarette socket, and it will charge your battery.
You can also bring it outdoors and use the crocodile clips to charge any 12V batteries. It is safe with protection against overcharging and a blocking diode to avoid reverse charging at night.
- Strongly built (shock and dust proof)
- Plug and play
- 10 W for battery trickle
- 18 months warranty
- Will not charge a dead battery
- Needs full sun to give its best
This product has the best quality/price ratio of all our solar battery maintainers. It is strongly built and will do a great job to compensate for your car battery’s natural loss.
- High Efficiency and Portable: The solar panel is 10W output, the size is 15.59*6.97*0.19inch and weight is only 0.86Lbs. The solar panel voltage is 18V, with reverse diode protection. So it is simple...
- Ultra-Portable and Comfortable: The Solar Panel Is With PET laminated and PVC Fabric, Ultra Light, Easy To Take Anywhere;
- Environment Friendly: Save Energy, Make Good Use of Unlimited Sunshine Anywhere,Best Power Resolution for All Kinds of Batteries In Remote Area For motorcycles, automobiles, snowmobiles, tractors,...
SUAOKI is a brand specialized in power stations and portable solar panels. They also have a range of products dedicated to cars. Let’s have a look at their 18W solar car battery charger.
This 12V solar car battery charger is one of the most powerful of the trickle charger category. It features an 18W solar panel (18V, 1Amp) that will have no problem compensating for your battery loss when your car is stored for a long period of time.
Unlike other models, SUAOKI features a flexible rainproof solar panel; therefore, it is super slim and can fit on non-flat surfaces. It can also be attached anywhere thanks to the four eyelets. It is roughly the size of two A4 pages and weighs only 0.76 lbs.
Thanks to its cigarette socket connector, it is plug and play. You can also connect it to any 12V battery with its crocodile clips.
It is safe to use with the blocking diode that prevents reverse charging overnight.
- 18W of solar power (18V, 1Amp) to maintain your car battery
- Lightweight flexible solar panel
- Plug and play
- No suction cups
- Cannot fit in a bag
- Will not fully charge a dead battery
This is a great innovative solar car battery maintainer, with a super slim, flexible solar panel. Thanks to 18W of power, your 12V battery will never be drained even after months of storage.
- CAR BATTERY MAINTAINER: perfect for keeping automobile charged to lengthen the life expectancy of car batteries; output voltage of 18V and 18 watts of energy
- 18W SUNPOWER SOLAR PANEL: made of premium quality SunPower solar panel with high solar cell efficiency of 22.5%; 18W output works better than 4.5W, 7W of other similar products
- BUILT-IN BLOCKING DIODE: prevent your batteries from discharging backwards through your solar panels at night when charger’s voltage is lower
ECO-WORTHY is a small company specialized in solar power both for portable and domestic use. We are featuring their 25W model, with the promise of charging dead batteries. Let’s have a look at its main features.
The solar car battery charger from ECO-WORTHY is a kit including a 25W (18V, 1.2A) solar panel, a 3A solar charge controller with a USB output, and two connectors – battery crocodile clips and O-ring terminal cables.
Thanks to its 25W solar panel, this model is able to not only maintain the state of charge of your battery but also charge it. Of course, with only 1.2A maximum output, full charge will take a day for a 10 Ah car battery, but this is an entry model.
It can only charge your car battery when directly connected with the crocodile clips or the O rings. The solar panel is waterproof and could be mounted on top of your RV, for example.
Thanks to the charge controller, you are protected against overcharge, and you can charge your phone through the USB output.
Its size is reasonable, but it will not fit in a backpack with 17 x 13.8 x 1.4 in and 4.38 lbs. It is IP65-certified and suited to stay outdoors permanently.
- 25W of power to maintain and even charge your car battery
- Can charge a phone via USB
- Weatherproof (IP65)
- Good pricing
- Not really plug and play
This is a great entry-level car battery charger that will maintain your battery level at all times and can even achieve full battery charge. THis product is also perfect on the roof of your RV.
- [Plug & Play] SAE connectors cable is easy to install and virtual free maintenance and two cable with alligator clips (18.5inch) and O-ring terminal (16.5inch) for battery charging connection
- [Widely Used] Ideal solar power kit for variety of off grid applications including chicken coop, gate opener, water pump, shed, cabin etc where 12V deep cycle battery is used as well as charge and...
- [Durable Panel] Waterproof 25 Watt solar panel with 9.84ft SAE connector cable, SAE connectors easy to connect and disconnect with controller, plug and play
ACOPower is a trusted brand, specialized in solar products for the outdoors, like foldable solar panels, solar refrigerators, batteries, and accessories. We are glad to feature one of their products in our review. Let’s have a look below at its main characteristics.
ACOPower 12V 50W is a kit including a 50W foldable solar panel and a battery charge controller. It also comes with all the needed connectors, like crocodile clips.
The foldable design is really clever. It makes this solar car battery charger ultra portable. When folded, it is the size of a small briefcase. Unfold it, and you can attach it anywhere – thanks to the three loops.
It has great solar charging abilities, thanks to its 50W solar panel. The maximum output is 18V, 2.77A under full sun. Therefore, it can not only maintain your car battery but also charge it to its fullest capacity.
The PWM solar charge controller offers a high level of safety with overcharge protection and regulation. You can also plug in your USB device.
It is built with a strong canvas and comes with a 18 months warranty. The panel has a power output certified for 20 years.
- 50W of power to charge your car battery
- Highly portable
- Foldable design
- High-quality material (18 months warranty, certified 20 years power output)
- PWM solar charge controller (MPPT is best)
- A bit more expensive than classic 50W solar panel
A great product from ACOPower, we especially like the foldable design and its 50W power. It is able to maintain your car battery and also charge a dead battery under full sun.
- High Conversion Efficiency: 50W monocrystalline photovoltaic kit was made of 4 pcs 12.5W solar panels
- Highly Portable: Features ultra lightweight design (92 oz), laptop-like storage size of 14.2 x 11.4 inch
- Multi-Purpose: Charges 12V lithium and lead acid batteries, provides a USB 5V output for phones/USB devices when connected to the battery. Features removable charge controller for solar generator,...
DOKIO is a solar panel brand specialized in outdoor products. We are featuring their most powerful model, which is also the most powerful solar car battery charger available on the market.
Two features are making the DOKIO 220W a unique solar car battery charger – its design and its power output.
Indeed, DOKIO has chosen a foldable design with four 55W solar panels. The result is a super portable and easy-to-handle solar car battery charger. When folded, it is the size of a suitcase and only weighs 9 lbs. Given its power, this is quite impressive. Unfold it, and you can easily adjust the solar panel orientation to maximize power output.
It can produce up to 220W at 18V, 12 Amps. It is enough to charge a regular car battery from dead to full in less than a day. You might even be able to connect two car batteries during sunny days.
It comes with a solar charge controller to ensure smooth car battery charging and protection against overcharge. A complete set of connectors is included, with crocodile clips for battery charging.
Like all DOKIO’s products, it is built for the outdoors and will withstand the rain. Finally, it is well-priced given its power output.
- 220W of solar power (car battery from 0% to 100% in 3 hours)
- Foldable design
- Easy to handle
- Built for the outdoors
- Well priced
- PWM charge controller (MPPT is better)
- No built-in stands
If you want to truly charge a dead battery, this is your solution of choice. It is ultra compact, will fit in your car or RV, and powerful with 220W. It will charge anything in a few hours.
- 【FOLDABLE AND LIGHTWEIGHT EASY TO CARRY】-- This solar panel photovoltaic packs 220W of power yet is only 0.9inch (2.4cm) thick and weighs only 9lb (4.1kg), making it easier to mount,transport,...
- 【PERFECT CHOICE FOR OUTDOOR AND EMERGENCY LIFE】-- 9.85ft (3m) cable length from panel to controller, For most power stations (Jackery,Goal Zero,Ecoflow,Paxcess) and 12-volt...
- 【AFFORDABLE AND HIGH CONVERSION EFFICIENCY】-- With high efficiency monocrystalline solar cell, you will get greater power efficiency even though the panel is smaller than a traditional model.
Solar Car Battery Charger: FAQ
Do Solar Car Battery Chargers Work Better Than Normal Chargers?
They don’t work better – they work differently. Solar battery chargers will only provide low-charge current, thus acting as a battery maintainer. Regular chargers provide higher current and can fully charge a battery in a few hours.
How Long Do I Need to Charge a Car Battery with a Solar Charger?
If you are looking to fully charge your battery, depending on the power of the solar charger, it could take as long as 2 days. With the most powerful solar battery charger (220W), it can take only 4–5 hours under full sun.
Do Solar Car Battery Chargers Charge Dead Car Batteries?
Only solar battery chargers with power above 25W are able to charge dead car batteries; however it will be very slow. For full charge, models above 60W are recommended.
How to Test a Solar Car Battery Charger
Lay your solar car battery in full sun, and connect it to an electric tester. The voltage should be higher than 12V.
Do I Have to Disconnect the Solar Charger When I Start the Car?
No. If you are using a solar battery maintainer, it can stay plugged all the time so that your battery will never be drained.
How Long Would It Take to Charge a Tesla Car Off a Solar Battery Charger?
Assuming that you use the most powerful model of solar car battery charger at 220W, charging the Tesla Model 3, will take between 60 and 90 days.
Our review is coming to an end, and we hope that you now have all the keys to wisely choose your solar car battery charger.
Don’t forget that models below 25W are battery maintainers and will only compensate for the natural loss of your car battery.
They should be connected at all times when your car is not in use. Models above 25W can charge a dead battery with solar energy, similar to a regular car charger.
Finally, solar car battery chargers will save you the stress of the dead battery, as they will keep your battery up, even if you don’t use your car for months.
Solar chargers are your car battery’s best companion!
If you are missing a point, we will be pleased to help you. Feel free to leave us a comment below.