Best Solar Trickle Chargers For Motorhomes, RV’s, and Caravans
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A solar trickle charger will provide the opportunity to keep your RV battery from dying out when it is not in use. But which solar trickle chargers work best for RVs, motorhomes, and caravans?
The best solar trickle chargers for RVs have at least 15 watts of maximum power. They also have controllers to prevent overcharging from occurring. Additionally, some of the leading brands have 3-piece SAE connectors, which provide you with versatility and can help prevent reverse polarity.
In the sections below, you’ll find out why solar trickle chargers can be so effective and which features to look for in a charger. Further down, you’ll find the 8 best solar trickle chargers on the market today, broken down and compared in terms of features and performance expectations.
What Is A Solar Trickle Charger?
Self-discharging occurs to some extent in most types of batteries, including the 12V batteries used in the automotive industry. This causes a decrease in the stored charge of a battery over time. The rate of this decrease depends on a host of factors, including the type of battery, ambient temperatures, charging current, and much more.
A solar trickle charger replaces the self-discharge of a battery so that the battery will not go dead. These are most effective in the flooded lead-acid batteries used in RVs because the rate of self-discharge can be as high as 30% in a month.
Why would an RV battery go dead? Lead-acid batteries can die out if they are left unused for several months. RVs and caravans are often left to sit in one location for several months at a time, whether in storage or at an RV resort offering seasonal residency.
A solar trickle charger fights against the rate of self-discharge by continually charging the battery.
What Does A Solar Trickle Charger Do?
The power source for the charger is a small solar panel, making the entire unit small enough to fit in the back of a vehicle or inside one of the cargo holds in your RV.
All you have to do is connect the positive and negative electrodes to the corresponding terminals on the battery. The wires are small enough to be fed through tight spaces, such as closed car hoods. The panel can then be laid flat on a surface that receives direct sunlight.
You do not have to worry about having access to a wall outlet or a shore power station. The entire kit is small enough to be stowed away at any storage compartment onboard your RV or camper.
Solar trickle chargers serve a broader purpose than just maintaining 12V batteries. They also often come with built-in charging ports that allow you to charge your electronic devices, such as cell phones, tablets, and laptops. This comes in handy when you’re camping remotely, without access to a reliable source of electricity. It also helps you conserve energy use in your RV.
How Strong Of A Trickle Charger Do You Need For RVs?
You don’t need more than a single solar panel to trickle charge an RV battery, although the ideal wattage does depend on several factors. You’ll need to know how much power is being drained from the battery.
Here’s how to determine this:
- Determine the battery’s storage ability, which is often in the range of 75 amps.
- The storage capacity can be divided by the amount of time it takes for the power to be completely discharged.
- You need to find a solar panel that produces enough amps per day to replenish the discharge.
In terms of watts, you’ll be looking for something with at least 15-20 watts for keeping an RV or camper battery charged. Many of the same manufacturers that package the trickle chargers listed below also make smaller chargers that are great for cars, ATVs, boats, and the like.
What To Look For In A Solar Trickle Charger
It’s hard to compare solar trickle chargers unless you know the differences between the numbers and features. In the section below, you’ll learn about which features to look for in a solar trickle charger.
Multiple Ways To Connect To The Battery
Many solar trickle chargers come with multiple different ways to connect to a battery. Some come with alligator clips, o-rings, and a cigarette lighter plug. This eliminates the possibility that you may have to keep a hood/door open to charge your battery.
Being able to connect to a cigarette lighter plug also reduces the chance that reversed polarity will occur (positive and negative electrodes misplaced).
Solar Panels: Polycrystalline vs. Monocrystalline
You’ll notice that the solar panels in trickle chargers are either polycrystalline or monocrystalline. This makes a difference in how effective a given solar panel is. However, the difference is not as significant in solar trickle chargers, where the panels are much smaller than those found on the roofs of homes and businesses.
Polycrystalline
These types of solar panels are made out of many silicone fragments melted together. They are typically more affordable than monocrystalline panels, although they are less efficient. You can tell them apart visually since polycrystalline panels tend to have a bluish hue, while the monocrystalline is black.
Monocrystalline
These types of solar panels are made out of solar cells, which consist of a single crystal of silicon. Monocrystalline panels are more efficient than their polycrystalline counterparts. They also come at a higher cost, so anything with this type of solar panel can be considered a premium product.
Solar Cell Protection
There can also be differences in the type of material used to protect the solar panel. This can affect the overall durability of the product. You may be able to find an affordable charger, but will it stand the test of time? Below you’ll learn more about how to get a good read on the durability of your solar panel.
Solar panels can be made from two different types of glass: either tempered or flat plate. The tempered option is six times greater in terms of strength than normal plate glass. As such, it is a much more durable option and will reward you with a product that is much less easy to break.
You’ll also see many of these options featuring ETFE as the exterior material. This is a honeycomb-like structure that protects the solar cells. Many solar trickle chargers also have aluminum frames, which help keep the panel from getting roughed up.
Look For A Charger With A Charge Controller
A charge controller is a valuable tool when you are using a trickle charger. This is a piece of equipment that prevents the battery from becoming overcharged. Once the battery has received a full charge, the system is cut off from delivering more juice to the battery.
There are typically two different types of solar controllers: PWM and MPPT. The main difference between the two is that the PWM works slowly by constantly supplying a small amount of power to keep the battery topped off. MPPT (Maximum Power Point Tracking) controllers, on the other hand, adjust their input to deliver the maximum power possible.
8 Best Solar Trickle Chargers For Motorhomes, RVs, And Caravans
Below you’ll find the top 8 trickle chargers on the market, along with the top features associated with each. That’ll help you make a decision when it comes to getting the best solar trickle charger to suit your needs.
| Charger Name | Top Feature |
| OYMSAE 30W | 3-piece SAE cable |
| POWISER 20W | Built-in charging microprocessor |
| SOLPERK 20W | Designed To Charge 24V |
| SUNER POWER 20W MPPT | Maximum Power Point Tracking |
| TOPSOLAR 20W | Simplified LED indicator |
| MEGSUN 20W | USB 5A/2V output port |
| SUNAPEX 20W | PCB layer for durability |
| POWOXI 20W | Smart controls prevent overcharging |
OYMSAE 30W Trickle Charger
The OYMSAE 30W Solar Trickle Charger is a monocrystalline charger contained within an ETFE housing with a light transmittal engine of 95%. The PCB bottom plate on the solar panel reduces the risk of panel breakage due to weathering. The charger also comes with a 1-year warranty.
This solar trickle charger comes in a size that is easily portable, weighing just 1.4 lbs and measuring 14.3″ x 13.58″ x 0.79″. As far as mounting hardware, it seems that only plastic suction cups are provided, which is fine as long as you are mounting on a windshield or other flat surface.
Best Features
The most notable feature of this charger is the 3-piece SAE cable that allows you to have multiple choices in terms of charging methods. The 3-piece kit includes alligator clips, cigarette lighter plugs, and an o-ring terminal.
This trickle charger also claims an IP65 waterproof rating. This rating is defined as “protected from dust” and “protected against water jets from any angle.” As such, the claim is that you should not have to worry about this panel if you leave it out in either rain or snow.
| Parameter | Value |
| Exterior Material | ETFE |
| Monocrystalline Or Polycrystalline? | Monocrystalline |
| Product Dimensions | 21.2” x 13.6 “ x 0.79” |
| Maximum Power (Watts) | 30W |
| Open-Circuit Voltage (V) | 21.6V |
| Optimum Operating Voltage (V) | 18V |
POWISER 20W Trickle Charger
The POWISER 20W Trickle Charger comes with an advanced LED indicator system. A blue light tells you to put the solar panel in the sun, while a red light tells you that the battery is being charged. A green light indicates a 100% charge level. The charger has durable elements too, with a sturdy layer of epoxy on the bottom.
If you are looking for a charger that is easy to carry, this charger is a suitable match. It weighs just 1.4 lbs. and measures 14.3″ x 13.58″ x 0.79″. You will notice that this makes it one of the more portable options on this list.
Best Features
The best feature is the built-in charging microprocessor designed to improve the charging algorithm. This also protects against overvoltage, overcharging, and short circuits. This is an excellent attribute for trickle chargers to have since overcharging can be a concern with battery maintainers.
The POWISER is also versatile since it comes with a 3-piece SAE cable kit. This means that you can plug this charger into a cigarette lighter plug if you wish to do so. This charger also comes with suction cups and carabiner clips to keep the panel attached to the surface of choice.
| Parameter | Value |
| Exterior Material | ETFE |
| Monocrystalline or Polycrystalline? | Monocrystalline |
| Product Dimensions | 14.3” x 13.58” x 0.79” |
| Maximum Power (Watts) | 20W |
| Open-Circuit Voltage (V) | 21.6V |
| Optimum Operating Voltage (V) | 18V |
SOLPERK 20W Trickle Charger
The SOLPERK 20W Trickle Charger comes with tempered glass, weatherproof film, and an aluminum frame to account for rain, snow, and sun.
This charger also comes with an adjustable mounting bracket that can be rotated 360 degrees so that you can place your panel directly in the path of maximum sunlight. This is a superior alternative to the suction cups found on many solar trickle chargers.
This solar panel does come with two connectors and alligator clips, but it does not appear to come with the 3-piece SAE cable that some other charging kits do come with. This offers a little less flexibility when it comes to connections.
Best Features
The best feature of the SOLPERK 20W Trickle Charger is the fact that it is designed to charge 24V batteries or two 12V batteries in series. The advantage of 24V batteries is you can run a smaller diameter wire than you would with the more common 12V option.
This may help you reduce wiring costs and is most effective in scenarios where long wire runs are necessary.
The solar panel is protected by a layer of tempered glass and an aluminum frame. This offers superior protection against rain or snow. The anodized aluminum frame also protects the solar panel from corrosion.
| Parameter | Value |
| Exterior Material | Tempered Glass |
| Monocrystalline or Polycrystalline? | Monocrystalline |
| Product Dimensions | 14.6 x 13.2 x 0.7 |
| Maximum Power (Watts) | 20W |
| Open-Circuit Voltage (V) | 18V |
| Optimum Operating Voltage (V) | 12V |
SUNER POWER 20W MPPT Charger
TheSUNER POWER 20W charger comes with an MPPT charge controller. MPPT stands for Maximum Power Point Tracking, which is a system designed to extract the maximum amount of available power from a PV module under certain conditions. This type of controller generates 10-20% more power than traditional controllers.
This comes with a polycrystalline solar panel rather than the monocrystalline cells seen in many other solar chargers. This helps keep costs down, as MPPT controllers are pricier than other types of solar controllers. The main difference with polycrystalline is that these types of solar cells tend to be less efficient than monocrystalline.
Best Features
This charger also comes with a feature that automatically cuts off the charge once the battery has become fully charged. As soon as the battery becomes flat, the charger is activated once again. This eliminates overcharging concerns, particularly when you are not able to routinely check up on the system to make sure that there aren’t any problems.
The IP 65 waterproof design means that the solar panel is built to withstand rain and snow, as well as the intrusion of dust particles. It is also hard to beat the durability of the ABS frame and the tempered glass cover.
| Parameter | Value |
| Exterior Material | Tempered glass |
| Monocrystalline or Polycrystalline? | Polycrystalline |
| Product Dimensions | 16.5” x 13.19” x 0.67” |
| Maximum Power (Watts) | 20W |
| Open-Circuit Voltage (V) | 22.32V |
| Optimum Operating Voltage (V) | 18V |
TOPSOLAR 20W Trickle Charger
The TOPSOLAR 20W Trickle Charger is made of a heat-resistant and waterproof material. It can be attached two ways: either on the windshield with suction cups or with an open car hood. It comes with both a cigarette lighter and an alligator clip.
This solar charging kit comes with suction cups and carabiner clips for mounting, which offers less versatility than the options on this list which have mounting brackets that can be adjusted 360 degrees. On the plus side, this is one of the smaller panels in this list.
Best Features
The electrical components are protected in a weatherproof junction box. One of the nicer features is a simplified LED indicator. It has a normal working indicator and a polarity reversal indicator. The latter tells you if the electrodes are connected backward, a feature not commonly seen in other trickle chargers.
This charger does come with a cigarette lighter connector, which allows you to connect to the battery in a way that makes reverse polarity less likely.
| Parameter | Value |
| Exterior Material | Heatproof/waterproof material |
| Monocrystalline or Polycrystalline? | Monocrystalline |
| Product Dimensions | 14.17 x 13.1 x 0.1 |
| Maximum Power (Watts) | 20W |
| Open-Circuit Voltage (V) | 14.5V |
MEGSUN 20W Trickle Charger
The MEGSUN 20W Trickle Charger comes with an adjustable mounting bracket that claims 50% more solar energy collection than horizontally-mounted panels. This solar charger comes with an 18-month warranty, which gives you plenty of time to measure its performance before deciding if it’s worth it.
This solar trickle charger is built with strong tempered glass and an aluminum frame for enhanced durability. The solar cells are polycrystalline rather than monocrystalline, which certainly helps make the charger more affordable but also leads to a slight dip in efficiency versus the chargers with monocrystalline panels.
Best Features
The best feature in the MEGSUN is the Smart 4-Stage PWM, which is designed to improve efficiency and prolong the life of the battery by preventing overcharging.
This charger also comes with a USB 5V/2A output port capable of supporting cell phones, laptops, and other electrical devices requiring 5V voltage. You can keep all your devices charged, even when you are traveling remotely.
| Parameter | Value |
| Exterior Material | Tempered glass and aluminum frame |
| Polycrystalline or Monocrystalline? | Polycrystalline |
| Solar Panel Dimensions | 13.19” x 14.57” x 0.67” |
| Maximum Power (Watts) | 20W |
| Open-Circuit Voltage (V) | 22.4V |
| Optimum Operating Voltage (V) | 18.2V |
SUNAPEX 20W Solar Battery Charger & Maintainer
The SUNAPEX Solar Charger & Maintainer is designed to be more efficient, thanks to a special honeycomb structure. This is another solar charger that has a three-color LED indicator. This lets you know when the battery is receiving sunlight and when the battery is fully charged.
For mounting hardware, the SUNAPEX comes with carabiner clips for easy mounting on surfaces, but it does not come with the 360-degree bracket that some trickle chargers come with. This may make the SUNAPEX less adjustable than chargers with mounting brackets.
Best Features
One nice feature is the layer of PCB designed to make the panel more robust. Many solar panels can be susceptible to internal chipping due to weathering. The solar panel also contains the honeycomb-like ETFE exterior allowing light to travel twice.
This solar charger also comes with a 3-piece SAE cable kit that makes it easy to connect the charger to a diverse selection of vehicles, including RVs, campers, cars, and ATVs.
| Parameter | Value |
| Exterior Material | ETFE |
| Monocrystalline or Polycrystalline? | Monocrystalline |
| Product Dimensions | 14.4” x 13.4” x 0.39” |
| Maximum Power (Watts) | 20W |
| Open-Circuit Voltage (V) | 18V |
| Optimum Operating Voltage (V) | 12V |
POWOXI 20W Solar Trickle Charger
This POWOXI 20W Solar Trickle Charger comes with six magnets so that you may easily mount the panel in the path of direct sunlight. The solar panel kit also comes with much-needed safeguards such as overload protection, short circuit protection, and the like.
You’ll notice that the POWOXI 20W charger is rated as an IP-65 waterproof device. This means that it should be able to handle rain without issue. An ABS plastic frame makes the panel easy to carry and can help protect it against damage if it is accidentally dropped or stepped on.
Best Features
The kit also comes with a 3-stage PWM charging controller that adopts three types of charging called fast charging, upgrade charging, and floating charging. The manufacturer claims that this can generate at least 10-20% more power over a traditional controller. The charger is equipped with an STM 8 microprocessor to prevent overcharging.
| Parameter | Value |
| Exterior Material | ABS frame |
| Monocrystalline or Polycrystalline? | Monocrystalline |
| Product Dimensions | 16.9” x 14.96” x 1.57” |
| Maximum Power (Watts) | 20W |
| Open-Circuit Voltage (V) | 12V |
Are Solar Trickle Chargers Worth It?
Vehicle batteries maintain an adequate charge for 9-12 months when they are left sitting. You certainly need some way to keep your RV batteries from going dead when they are in storage. A solar trickle charger is one of the most cost-effective ways to do this and will work as long as you know what to look for.
Can’t you just disconnect the battery? Yes, you can indeed disconnect the battery while the RV is sitting, but there’s a good reason not to do this. This is because newer vehicles, including RVs, will lose their settings if you remove the battery, even temporarily.
Do You Need Sunlight For A Solar Charger To Work?
Solar chargers do not necessarily need direct sunlight to work, but they do need to receive at least some exposure to the sun. These chargers can work on cloudy days for the same reason that you need to apply sunscreen on cloudy summer days: up to 80% of the sun’s UV rays can find their way through cloud cover.
Still, solar trickle chargers will be more effective if they can be placed in direct sunlight. This is why many of the products listed below have 360-degree mounting brackets that allow you to easily adjust the panel for full exposure to the sun. To prevent the battery from being drained during nighttime, solar chargers commonly come with a feature that will automatically shut them off when it gets dark outside.
How Long Do Solar Trickle Chargers Last?
You’ll notice that many solar trickle chargers come with warranties in the range of 12-18 months. They can last for many years beyond the warranty, as long as you take good care of the solar panel and the other charging components.
Be sure to regularly clean your solar panel, as removing dust particles will also help maximize the energy yield of your solar panel. Whenever you aren’t using the charger, stow the solar panel and other electrical components in a dry location, such as a cargo hold inside your RV.