How to Choose Solar Battery Maintainers for Car, Rv & Boat

Apart from slow internet, nothing else is more frustrating than a discharging battery. One minute it is full and running and an hour later, it is below 9V! However, you can get one of the best solar battery maintainers. It will help you resuscitate your battery.

As long as there is some sunshine, you can keep your 12V battery juiced up ready to start your car, tractor, boat or snowmobile. Tell you what … you can keep the solar battery maintainer connected for the entire time that you need to keep the battery juiced up.

What To Consider for the Best Solar Battery Maintainers


Honestly, there are thousands of solar battery maintainers in the market. However, not all of them can be good for you. Therefore, to help you get the best value for your money, find out whether they fulfill the following factors.

 Pricing and Warranty

I know… we hardly start this section with the price but hey, there is a first time for everything. On that note, most solar battery maintainers cost between $20 and $35. However, it is also possible to find some going for more than that.

Whether it is cheap or expensive, check the warranty first before you buy a solar battery trickle charger and maintainer. For instance, most of them come with a warranty of 12 months. In addition, the manufacturer can promise lifetime technical support, which you might never use.

Basically, we think that a warranty of 12 months for a $25 solar panel battery maintainer is a fairly good deal. Therefore, you can buy such without hesitation.


Mostly, you will find the manufacturers of the best solar battery maintainers saying that there are chargers as well as maintainers.

However, that is hardly the case because most of them are just maintainers. By this, we mean that they can only top up a charged battery. Therefore, do not expect them to charge a dead battery.

Ease of Installation

Most of these solar battery trickle chargers and maintainers can be installed on the dashboard or on the roof of the RV. However, before you can install one on the roof of your RV or on your boat in exposure, make sure it is weatherproof.

Some models that we have reviewed come with nicely welded cases that cannot allow water into the panel. Such can be good for outdoor use.

On the other hand, when you buy a small solar maintainer for a car battery, you can install it on the dashboard. You can also install it on the passenger visor if it is small enough. That way, you can also rotate it depending on where the sun is.

In addition to easy installation, the boat, RV, snowmobile or car battery maintainers should come with installation accessories. These include suction cups for dashboard installation. In addition, most of them come with lighter plugs and battery terminal clamps.

If your car lighter works even when the ignition is off, you can use the lighter plug. On the other hand, if it doesn’t and you want to park your car, use the battery terminal clamps.

The Charging Ability

These battery maintainers usually come in three solar cell technologies. First, there is the amorphous technology, which is good for charging even on cloudy days.

Second, we have popular monocrystalline technology. This one is known for its black color. In addition, it has a high conversion rate of up to 25%.

Third, there is polycrystalline solar technology. Most solar panels running on this technology are identifiable by their blue color. On the same note, they are good, but they have a lower conversion rate.

Mostly, we park our cars, trucks, pontoon boats, RVs and other vehicles for winter. Therefore, it is at this time that we truly need to keep the batteries topped up. Consequently, it is good to have a solar 12-volt battery maintainer with the ability to recharge even on overcast days.

However, if you just need a solar panel to make up for the daily battery drain for your SUV, you can just go for the cheapest one.

Blocking Diode

In our review section, we tried hard to bring you many 12-volt solar battery chargers with blocking diodes. This is very important because it prevents reverse discharge at night, where the voltage flows back to the solar panel maintainer. This can cause damage to your maintainer and battery.

Build Quality

Simply go for the best! We have had instances where solar panels melt when exposed to the extreme Texas or California heat. Therefore, you might wonder why it does this yet it is supposed to work with and in the sun. Most of the time, it has to do with the design and build quality.

Frequently Asked Questions


If this is your first time buying a solar-powered 12-volt battery charger and maintainer, you might need more clarification. Here are some of the most frequently asked questions:

How do you use a solar battery maintainer?

It is very simple. First, you need to set it at a place that receives enough sunshine or sunlight. This includes the dashboard or the passenger visor.

Secondly, you will need to plug the provided plug into the lighter. In addition, if you are using the battery alligator clamps, you should attach them first and then plug them into the panel.

Third, disconnect the SAE cable when starting the car, or remove the terminal clamps/plug from the lighter.

Will a solar battery maintainer charge a battery?

It will charge a battery that is not flat out. Mostly, it will charge a battery that has at least 60 percent voltage. Therefore, we refer to it as a maintainer, meaning that it maintains a charged battery rather than a charger. However, a solar battery charger can also be useful as a maintainer.

Can I leave a solar car battery maintainer on all the time?

Because they come with blocking diodes that prevent reverse discharge at night, you can connect your solar battery maintainer, install it on the dashboard and leave it on all the time. However, you just have to unplug it from the lighter when starting the car, if the manufacturer says you have to do that. Therefore, it is a “plug and forget” kind of thing.

Solar Battery Maintainer Reviews 

If you have a car, a truck, tractor, snowmobile, RV, boat or any other machine that uses a 12V battery, you need the best solar 12V battery maintainer. There are so many of them that you will be spoilt for choice. However, here, we are going to review the top 10 of them. Keep reading!

1. ALLPOWERS 18V 12V Solar Battery Maintainer

If you have a car that you do not drive that often, you might need to buy a battery maintenance charger like this one. In fact, you can keep it on all the time, just turn it towards the light so that it keeps the battery charged up all the time. But first, you need to see the features.


This 12V solar battery maintainer kit comes with the solar panel itself, which runs on monocrystalline technology. Therefore, you can be sure that this solar panel has a high conversion rate and it is very good at harnessing sunshine.

In addition, the kit also comes with a cigarette lighter plug. Therefore, you can install it on the dashboard and plug it into the lighter. In that case, it is going to keep the car battery continuously topped up. However, if your car lighter does not work when the ignition is off, you can use the provided alligator clips.

To get it to work, connect the solar panel to the cigarette plug and the battery will start charging, as soon as the solar panel faces the light. In addition, you can install the panel where you like, or where there is the most sunlight. For instance, some people install theirs on the passenger visor where they can rotate it to catch the sunshine. However, you can also install it on the dashboard.

This is a small solar panel and charging kit. However, it works very well, but there is a small catch. You have to make sure that your battery voltage is higher than 60 percent. If it is, this 12V battery maintainer kit will not charge it.


  • Small enough to fit on the dashboard of your car
  • Charges using the cigarette lighter plug
  • Comes with suction cups for easier installation
  • Has a blocking diode to prevent reverse discharge


  • It is not good for outdoor use
  • Does not charge flat batteries

Bottom Line

This solar battery maintainer kit is going to keep your battery ready to move at any time. It will work as expected but you have to turn it towards the light.


2. TP-solar 12 Volt Solar Battery Maintainer

This is a straightforward solar kit to use to keep your battery fully charged all the time. TP-Solar has been in the industry for decades. However, you need to see the features that this kit comes with before you can commit your money.


This one is called a kit because it comes with a 10A solar charge controller. Therefore, even when the sun is blazing super hot, you need not worry about overcharging your battery or causing a fire. When the battery is fully charged, the solar controller prevents more current from passing to the battery. When the battery discharges, it kicks in to allow more current.

This kit measures 16 by 14 inches. Therefore, it will take some maneuvering to fit on your dashboard if it will. However, for a boat battery, it is just fine. In addition, the weight is minimal at less than 3 pounds, so it should be easy to carry with you.

You can use this solar panel outdoors in any kind of weather. After all, this is a waterproof solar battery maintainer. Therefore, you can install it outside to charge your remote-controlled gate battery. You can also install it on your boat and the water will not damage it. The face is made with tempered glass, which survives well in strong winds, sleet and rain.

Supplied with alligator clips for battery and a 10A charge controller, installation is superbly easy! Just read the user manual. Besides, TP-Solar offers good technical support.

In spite of these benefits and features, some improvements could help. For instance, the 10A controller is only good for lead-acid batteries. Therefore, you might have to look elsewhere for gel, li-ion, open and sealed batteries.


  • So simple to install anywhere that you like
  • Small size and minimal weight make it easy to travel with
  • The monocrystalline panel has a high conversion rate
  • Weatherproof design for outdoor use


  • The charging ability for small solar panels is highly dependent on the weather

Bottom Line

While this TP-Solar solar battery maintainer 12V kit has some disadvantages, the benefits are much more. Therefore, it will give you good value for money.


3. SOLPERK 12V Waterproof Solar Battery Maintainer

You might want to try the Solperk 12V solar battery charger and maintainer if you have a car that you do not use all the time. The SOLPERK name is not a stranger in the solar industry. However, you need to see the features first, before you can buy this one.


The solar panel is small and nifty enough to fit on the dashboard of your car. However, do not let the small size fool you because it is very efficient. In addition, it comes with amorphous technology and the cells can harness energy even when there is cloud cover.

As far as battery chargers and maintainers go, this one pretty much plugs and play. Therefore, you just have to switch the ignition off and plug in the cigarette lighter plug. If the LED lights up, you will know that your car lighter works even when the ignition is off. Therefore, you can leave the solar panel plugged in all the time to charge the battery.

One of the worries for many users of solar battery maintainers is that it will reverse discharge at night. However, SOLPERK has already taken care of this by installing a blocking diode. Therefore, when you leave it plugged in at night, it stops the battery from discharging.

There are many more features to this solar panel battery maintainer. However, it also has a few downsides. For instance, if you plug it into the battery terminals using the provided alligator clips, you have to remove them when starting your car.


  • Comes with a cigarette lighter and alligator clips for connection
  • Easy to install anywhere on your car’s interior
  • Keeps your battery topped up all the time
  • Sold with a warranty of 12 months


  • Some people complain that they’re melted in extremely high temperatures

Bottom Line

This is one of the most recommended trickle chargers for maintaining your batteries in top condition. It works as advertised.


4. Sunway Solar Car Battery Maintainer

Owning this Sunway solar car battery charger and maintainer is one of the best ways to keep your 12-volt battery always topped up. Sunway makes affordable solar products for different home needs. This solar battery maintainer is one of them. See its features below.


This solar battery maintainer kit is not going to overcharge your battery. Therefore, you can leave it connected even in the hottest sun and you can be sure that your battery is going to be safe. However, before you connect it, you need to ensure that your battery is 12V and 20Ah or bigger.

For such a small unit, installation is so simple. Therefore, you can install it on the dashboard and it will not get in your way. However, you need to make sure that it does not reflect on your windscreen when you are driving.

While it is not advisable to leave this solar panel outside in serious weather, the panel is made with high-quality PV glass. In addition, the frame is made of high strength ABS plastic. On the same note, there is practically no maintenance needed for this charger. You just need to wipe it down and it is good to use.

When buying a solar 12V battery maintainer, most people want a kit that can charge every type of battery. And this one can! Therefore, if you have a Gel, AGM, Deep cycle battery, flooded or SLA battery, it is going to trickle-charge all of them.

Finally, we must mention the built-in blocking diode that prevents the reverse discharge of the battery at night. Therefore, when you have a tractor, motorbike, car or mower that uses a battery and you know you won’t use it soon, you can use this charging kit to keep the battery topped up.

We could go on and on about the benefits and features of this solar car battery maintainer. However, this unit is not waterproof. Therefore, it is best that you do not use it in an unsheltered place.


  • Trickle-charges a 12V battery and maintains the charge
  • Installation is simple even if it is your first time
  • Comes with suction cups for installation on the dashboard
  • You can leave it plugged into your car if your lighter works with the ignition off
  • Different methods of installation if your lighter doesn’t work with the ignition off


  • You may not use this kit outdoors exposed to weather

Bottom Line

Simple to install, the ability to trickle-charge the battery and maintain the available charge are some of the benefits to expect from this kit. It might meet your battery charging and maintenance needs.


5. Schumacher 12 Volt Solar Battery Maintainer

RV, car, boat, snowmobile and indeed other 12V batteries have one thing in common – they gradually lose their charge, a little at a time. Therefore, if you would like the engine to ignite with just one crank after some time in the parking, you might love the Schumacher SP-200 battery maintainer. See more of its features below:


First, this 12V solar battery charger comes with a cigarette lighter plug. Therefore, you can find out whether your lighter works when the ignition is off. On the other hand, if it does not, you will just follow the instructions to plug the solar panel into the battery using the alligator clips. In addition, please note that whether you use the lighter plug or clips, you will have to remove before starting the car.

The solar panel uses amorphous technology. Therefore, it can capture energy even on a cloudy day. However, basically, these kits work well when there is some sunshine. In addition, you cannot use it to charge a dead battery. If the battery has discharged below 60 percent, it will not charge.

The build quality of this solar battery maintainer is admirable. The manufacturer has seamlessly welded the frame and solar panel. Therefore, it is waterproof so you can also use it on boats.

The only disadvantage with this solar trickle charger for RV is that it does not have an LED indicator light to let you know when it is charging or when it has stopped.


  • Water resistant design enables outdoor use
  • Easy to install even if this is your first time
  • Good design and build quality
  • Can charge a little even on cloudy days


  • It would be much better if it came with an LED light to show status

Bottom Line

This no-frills battery maintainer solar panel can work using the lighter or the provided clips. You can use it if you park your car away from the closest electricity outlet.


6. SUNER POWER RV Solar Battery Maintainer

This 8-Watt SUNER POWER 12-volt battery maintainer gives you the flexibility to top up your car, motorbike, RV or boat batteries anywhere. In addition, if you do not drive around a lot, you might want to start using this battery.


First, you will be happy that this solar charger for batteries not only tops up the voltage using the power of the sun but that it also prevents damage. Indeed, it can help to prolong the life of your battery. Thanks to the built-in blocking diode, this charger is going to stop your battery from discharging at night.

Even with minimal care and maintenance, this solar panel kit can last a long time. After all, it is built with a high-quality ABS frame and premium solar glass. However, it is also important to note that most of these items are built for sheltered use. Therefore, do not expose it to rainfall, wind and sleet.

Most people want a simple to use system and this one is no different. For instance, you can use the cigarette lighter plug if your lighter works even when the ignition is turned off. On the other hand, you can use the clamps in the package. In addition, it should be easy because the black clamp is negative while the red one is positive.

In spite of the good design, construction and ease of use, this solar battery charger kit still comes with some downsides. For instance, you will have no idea whether this charger is working or not since it does not have an LED indicator.


  • Pretty simple installation even for beginners
  • Built to last over a long time
  • 12-month warranty and lifetime tech support
  • Might have a higher output so you might need to buy a solar controller


  • No way to know when it is or isn’t working

Bottom Line

Keeping your car, bike, tractor or boat battery topped up actually prolongs its life. Therefore, you might want to use the SUNER POWER battery maintainer because it works very well.


7. POWISER Solar Battery Maintainer

For an affordable price, you can have this POWISER solar battery charger for RV, car, pontoon boat, dirt bike, snowmobile and any other machine that you have. However, you should see its features first before you buy it.


First, you might appreciate that this battery maintainer works well with all types of batteries. Therefore, whether yours is lead-acid, lithium-ion, GEL or other, it is going to trickle charge it. However, just make sure that it is a 12V battery.

Second, solar panel technology is amorphous. Therefore, it is efficient with a high conversion rate. At the same time, the construction quality is quite good such that the solar panel can withstand torrential rains, hail, sleet and even strong winds. Therefore, if you have a remote-controlled gate that uses a battery, you might use this kit to power it up.

You do not want to be bothered about installing this solar panel. Therefore, you will be happy with the simple, plug-and-play design. By this, we mean that the kit comes with a cigarette lighter plug and a couple or clamps. The lighter plug is for cars whose lighter works even when the ignition is off. On the other hand, you can use the clamps if the lighter turns off when you switch off the ignition.

Like any other product, the POWISER solar panel 12v battery charger has many benefits and some downsides. For instance, it is not a charger; it is a maintainer. However, the sellers advertise it as a charger/maintainer, thereby misleading some buyers.


  • Comes with suction cups for the dashboard or other installation
  • No need for any extra cables
  • Will maintain a full battery even in cloudy weather
  • Heavy-duty construction for use in all weather


  • Need to unplug from lighter or unclamp the clips when starting the car

Bottom Line

No one needs a complicated solar battery maintainer system if all they that need is to keep the battery at full ca therefore, you might love the simplicity of this kit from POWISER.


8. MOOLSUN 10W Solar Car Battery Maintainer

Since its establishment in 2008, MOOLSUN has been bringing some affordable solar products for users of different categories. Therefore, we set out to find whether their 12 Volt solar battery maintainer and charger can help you. Here are its features:


First, this is a 10-Watt solar panel for maintaining your battery. While the manufacturer refers to it as a charger too, we feel that could be a bit misleading because it barely charges a dead battery. Therefore, please use it as a maintainer only, you know, to cover the minimal losses that your battery undergoes every day.

This is a monocrystalline solar panel with an efficiency of 23.5 percent. What this means is that 23.5 percent of the sunshine that lands on it converts to energy. Therefore, on a super bright day, this solar panel is going to fill up the battery fast.

You will be glad that it comes with an SAE connector for the solar panel. Therefore, this means that you need not bother about what is the negative or the positive cable. Just connect them! In addition, you can trickle-charge your car battery using the provided cigarette lighter plug or the alligator clip adapter. Of course, what you choose depends on whether your car lighter works even when the ignition is off.

Lastly, you ought to know that your battery is protected against losing charge at night. Therefore, to help with that, this 12V battery maintainer comes with a blocking diode that prevents reverse discharge.

Not to water the parade, MOOLSUN could improve some things here. For instance, this solar panel battery maintainer keeps on charging the battery even when it is full. Therefore, you cannot just set it up and forget it.


  • So easy to install and use
  • Keeps battery charge maintained at full all the time
  • Charges fast when there is bright sunshine
  • Comes with all accessories including suction cups


  • Naked wires at end of the clips going onto the battery terminals
  • No LED indicator light to show you status or progress

Bottom Line

When you have set up the MOOLSUN battery maintainer, do keep checking on it so that you do not overcharge your battery. This is especially vital on bright sunny days.


9. Sunforce 12 Volt Solar Battery Maintainer

If it is winter and you need to keep your RV batteries topped up, you might use the Sunforce 50022 5-Watt solar battery maintainer. However, only get this one after you see some of its features below.


First, for such a small solar panel, cell technology matters a lot. Therefore, in this case, the manufacturer has used amorphous cell technology, which is as good as the monocrystalline panel. Consequently, on bright days, you can expect this panel to do a fast job of topping up your battery.

Second, the build quality of this kit is excellent. In addition to high-quality solar panels, you also get an aluminum frame. Therefore, it is corrosion resistant and the entire kit is weatherproof.

Third, the kit also comes with installation accessories. For instance, you can use the lighter plug if your car’s lighter works when the ignition is off. In addition, you also get battery terminals if it does not. Either way, your 12-volt battery stays topped up all the time.

There are so many good things to say about its size, ability and outdoor use. However, there is one main flaw. For instance, the black clip from the solar panel is actually the positive one and the red is the negative one. If you do not install it that way, you will experience a serious battery drain.


  • Good for outdoor use
  • Simple to install and use but mind the wrongly colored battery clips
  • Will charge well to top up the battery even on cloudy days
  • Helps your battery to get to its intended lifespan


  • You might need to sand the plastic mounting tabs a bit for the panel to fit
  • Mismarked wires for battery clips

Bottom Line

If you have an unexplained car battery drain, chances are that you need a kit to keep it topped up when you are not using it. The 5-watt Sunforce might help you with that.


10. Sunway Solar Car Battery Maintainer

Another Sunway solar panel car battery maintainer and trickle charger make it to the list and it is simple to see why. If you have a snowmobile, a car or truck, a boat or a motorbike that you hardly use, you need to use a battery maintainer kit to keep the battery topped up. Therefore, this one might be it, but first, see its features.


This trickle charger and battery maintainer works with almost all types of batteries. Therefore, you can use it for your RV deep cycle batteries, GEL, SLA, Lithium-ion, Wet and AGM. In addition, Sunway says that this maintainer can top up these batteries without overcharging them.

The technology used in this solar panel is monocrystalline. It has a high conversion rate of up to 23.5 percent. Therefore, on bright days, it charges your battery fast. In addition, it will also charge on cloudy days, albeit slowly, so you will keep your 12V battery topped up all the time.

When your battery is charged, it might lose its charge at night. However, just leave this solar panel plugged in and it will prevent that. To do that, this solar panel has a built-in blocking diode. It is important to charge a 12-volt battery and it is more important to maintain whatever charge you get in.

Other features include installation accessories using the lighter plug or the battery terminal clips. However, there are downsides too. For instance, the charging ability depends on the weather. Therefore, on seriously overcast days, you will not be able to top up your battery.


  • Blocking the diode prevents reverse discharge at night
  • Cabled from the solar panel side so you just plug in at the terminals
  • Well built with high-quality ABS plastic casing
  • Sold with a warranty of 12 months


  • Only charges well on bright days

Bottom Line

This Sunway solar powered battery maintainer is pretty much a plug and plays solar panel. If you are buying it for your car battery, you don’t require any extra cabling.

Conclusion and Recommendation

Never let your car battery die on you! However, if you do not drive that often, you know this is going to happen.

On the same note, your car battery could be experiencing the usual battery drain. However, there is a simple way to stop that. Just buy the best solar battery maintainers and your problem will be solved.

Here, we recommend that you try the ALLPOWERS Solar Battery Maintainer. It has the sturdiest build. In addition, it is small and nifty enough to fit on your dashboard, while remaining conspicuous at the same time.

You just need to connect it and forget it. In addition, it has a blocking diode so your battery will not pass voltage to the solar panel at night.

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