The topic of the importance of solar panels for RV is something that will always come up in any conversation between RVers.
After all, the debate of whether it’s truly necessary is still yet to be settled.
Once the issue of the importance of solar panels has been resolved, you still have so many choices to make. Where do you put it? Do you get a portable one, or a giant panel for your rooftop? What wattage is perfect for you? Which charge controller to get? Do you go for a monocrystalline one or a polycrystalline? There are so many variables in play, which makes the decision-making process overwhelming
Portable solar power systems are an especially hot topic amongst RVers, simply because is so much you need to know before being able to choose the best one for you.
The Best RV Solar Panels Quick Picks:
What You Need To Know About RV Portable Solar Panels
There is A LOT to learn before you can buy the best portable solar power system to accompany you in your adventures.
Terms like wattage (watts), amps (amperage), volts (voltage) and even different controllers, are so casually thrown around in the discussion about choosing the portable solar panel for your RV. Not everyone is an electrician, so it’s understandable that it sounds incredibly complex to the average buyer.
To make things easier for you, here’s a short summary of what to know before you can be sure that your choice in a portable solar panel is the right one.
Do You Need RV Portable Solar Panels
While it sounds convenient and awesome, portable solar panels are not for everyone. On the contrary, a significant portion of the RV community don’t need any form of solar power system.
The only purpose of getting a solar power system is to charge the battery of your RV whenever there’s no outside power source available to plug into.
In short, solar power is for charging your RV whenever you’re not on the electrical grid, or you’re ‘off-grid’. Simple and easy.
Except it’s not. Because in general, RVs are off-grid more often than not. Since you’re going to be using your RV to drive to different places, you’re rarely going to find yourself plugged in unless you’re dragging a miles-long extension cord while you’re on the road.
Obviously not. Which means that when you’re driving (which is presumably almost all the time), you’re technically off-grid. However, this doesn’t immediately mean that a solar power system is necessary for you.
Most of the RV on the road nowadays have the ability to charge its batteries while you’re driving. Additionally, RVs that have their own engine typically have at least one alternator which can provide power for the house batteries (the power source of all the 12-volt appliances in the RV).
Most of the trailers also have something called an ‘umbilical cord’, which is an electrical cord connecting the RV to the tow vehicle, capable of charging the RV’s house batteries.
Additionally, if the places you go to often have a power supply for you to plug into, then a solar power system is redundant and unnecessary.
Even if you camp off-grid every once in a while, that still doesn’t mean you really need solar panels. Your house batteries may already have enough capacity to allow you to go through a few days without a power source — just make sure that the lead-acid batteries don’t get discharged below 50%.
After camping over the weekend, or even longer, you can just go home and plug in your rig to fill your batteries again.
The people who really benefit from having a solar power system are the ones who go camping in places with no power source a.k.a the boondockers. Especially the ones who have a relatively small battery capacity.
So if you see yourself boondocking or staying unplugged for extended periods of time, then it’s wise to invest in a solar power system for charging your batteries while off-grid.
Of course, there’s always the alternative of using a generator, but do you really want to listen to a generator’s noise when you’re probably camping in order to stay in a place where it’s nice and quiet? Of course not.
In short, if you’re the type that often stays in campgrounds with power supply, then you probably don’t need solar panels.
If you go to places with no power supply most of the time, then you definitely want to invest in quality solar panels, especially if you don’t want to deal with a generator.
RV SOLAR PANELS: ROOF MOUNTED VS PORTABLE
So you know for sure that your life will be made better by having a solar power system on your RV for charging the house batteries, great! Now, what you need to know is whether you need portable solar panels or roof mounted ones.
Both choices have their own pros and cons which you can use to decide which one is the best at fulfilling your needs.
One important fact to take note of is that a single portable solar power system can only output around 200 watts at most. A possible solution to bypass this cap is by utilizing several portable solar power systems with all of them connected to just one solar charge controller.
But this often ends up with a bunch of solar panels scattered all over the place, which may become a major source of annoyance. If you’re willing to deal with that, however, then it’s definitely an option.
Another possible choice is to go for a combination of roof mounted solar panels along with portable ones. This is especially great for those who require a lot of solar power capacity.
ROOF MOUNTED SOLAR PANELS
This type of solar panels is the easier of the two, since after setting them up, they will just remain mounted on your RV’s rooftop. This means you that you don’t go through the hassle of setting them up every time you arrive at a new campsite. If you’re the clumsy type, there’s also less risk of accidents.
This makes roof mounted solar panels reliable and easy. However, they may also be unnecessary, depending on your needs.
Additionally, it’s also important to note that if you’re the type to park their RV under the shade of trees, then roof mounted solar panels are going to have a harder time producing power.
- The solar panels are mounted on the roof permanently, so there’s no need for setting them up every time you use them
- Placed on the roof of your RV, so they don’t get in the way of your everyday life.
- Don’t have to be rotated throughout the day to follow the sun’s position
- Requires room on the rooftop of your RV to be installed
- Parking your RV under the shade of trees will result in the solar panels producing less power
- They are more expensive than portable solar panels and your solar power needs may not be big enough to justify the cost, especially if you’re getting a good system
- The solar panels have to be kept clean all the time, meaning you will need to climb up to the roof your RV often in order to clean the panels
PORTABLE SOLAR PANELS
If you feel like none of the pros are important to you, or too many of the cons apply to you, then chances are that what you need are portable solar panels.
Portable solar panels are perfect for people who just want to try out having a solar power system in order to find out whether they really need one. It’s also great for people who don’t require that much solar power. If you realize that you benefit a lot of from having a solar power system, or if your solar power needs suddenly increased, then you can still upgrade to a roof mounted system later down the road. The best part is that when you do upgrade to a roof mounted system, you can still use your portable solar power system for better efficiency and increased capacity.
So if this is your first solar power system, or if you only boondock occasionally, portable solar panels are perfect for you.
- Beginner-friendly, they are not a massive investment if you’re only trying to check out using solar power to charge your house batteries
- The perfect choice for people who don’t always camp off-grid, or whose RVs don’t have a lot of appliances that require 12-volt of power
- Since they’re not on top of your rig, you can park your RV under the shade of trees where it’s cooler, and just set-up your portable solar panels out where it’s directly under the sun
- They’re not permanently attached to your RV, so you can easily transfer them every time you change your RV
- Can be used in conjunction with roof mounted solar panels to increase your solar power capacity and give you the best of both worlds
- Solar power panels need to be cleaned regularly in order to allow them to operate at maximum efficiency. Since portable roof panels aren’t permanently attached to your roof, they’re a whole lot easier to clean compared to roof mounted solar panels
- Requires you to deploy them —set them up under the sun— every time you need to use them
- You’ll have to keep turning the solar panels every once in a while, so that they’re always facing towards the sun
- In terms of watts per dollar, portable solar systems are generally more expensive compared to roof mounted systems
- Once deployed, portable solar panels can be messy and hinder the movement of your everyday life. Be careful when moving around them, especially at night
Is your RV equipped with a Zamp Sidewall Solar Port? If that’s the case, then here’s something you need to know.
Zamp Sidewall Solar ports are an SAE connector, meaning you can use it to connect to ground mounted solar panels. This means that the RV is already made with the ability to use portable solar power systems.
Luckily, this does not mean that you can only use Zamp portable solar panels for your RV. Rest assured, you can whatever brand you prefer.
HOWEVER, do take note of the fact that the Zamp Sidewall Solar Port has reversed polarity. This means that the positive polarity and the negative polarity are reversed, so the wires will also have to be plugged differently (positive wire to the negative side of the battery and vice versa).
If it’s not yet obvious, proper wiring is incredibly important. If you try to do it carelessly, you’ll end up creating massive problems. How massive? Well, everything will get fried kind of massive.
But have no worries! Now that you’re aware of the possible problem, you can easily make sure it never becomes an issue.
In the event that the portable solar power system you desire is not made by Zamp, all you have to do is to buy either (or both!) of the adapters listed below and all your worries will be over.
Does your preferred solar power system have an SAE connector? In that case, all you need to buy is a SAE polarity reverser connector and problem solved.
If the solar power system you’re eyeing requires MC4 connectors, then you’ll need to buy not only a SAE polarity reverser, but also a MC4 to SAE connector.
When you have these two items, here is what you need to do:
- Plug your solar panel’s MC4 connector to the MC4 side of your adapter
- Plug the SAE connector of the adapter to the polarity reverser
- Plug the other end of the polarity reverser to the Zamp Solar Port.
Once all you’ve done all the plugging necessary, using the Zamp Solar port should be 100% safe.
If you don’t feel like you’re the type that needs that much solar power, or the cons of having a roof mounted system applies too much to you, then going for a portable solar power system is a great decision.
Additionally, portable solar power systems are much more versatile than roof mounted ones and can add flexibility to your set-up. For example, you can use them to augment a roof mounted solar power system, if you already have one or planning to upgrade to one. You can also use the portable system to gather power while leaving your RV under the shade of trees.
If you already have an existing roof mounted solar power system, here are a couple reasons why you should go for portable solar panels instead of another roof mounted ones:
- Solar panels produce more power when they’re directly facing the sun. This means that during winter, when the sun is relatively low, the flat roof mounted solar panels can’t manage to produce power at maximum efficiency. Ground deployed portable solar panels, on the other hand, can be tilted. This means that you can always have them looking at directly into the sun at the best angle, which is perfect for maximizing power production efficiency.
- Because they’re ground mounted as opposed to being attached to the roof of your RV, you can happily park your motorhome under shade to keep it cool without having to worry about the solar panels being covered. When it’s the middle of the day and the blazing sun is high above is the time for both charging your solar panels and leaving your RV under the shade where it’s cool and shaded. If you have a rooftop mounted solar power system, the shade will cover the solar panels, reducing efficiency. However, a portable solar power system can be deployed on the ground, right under the burning heat, while the RV itself is just chilling under the shade.
If your power consumption is higher than what a single portable solar power system can provide, but still not big enough to warrant a roof mounted system, then you can always just get two (or even more) portable solar panels and connect them all to one solar controller.
How much solar power does my RV need?
The most important question when it comes to choosing the most suitable solar power system for your motorhome is, “how much power do I need from my solar power system?”
Exactly how many watts do I need to buy to make sure that there is enough supply of power for my motorhome, including the needs of the house batteries
The short answer is that there isn’t one. Everyone has a different idea how much solar power is necessary, and they all think their opinion is the right one.
What should be the capacity of your portable solar power system? Just like with the power issue, there’s no quick answer for this problem, either. There are a lot of variables that can affect the amount of solar power you’ll need.
One of the things that can drastically affect the amount of solar power you can get from the house batteries of your RV is temperature. And its effects are HUGE.
Most of the RVs on the market have batteries made from lead acid. They are rated based on their ampere hour (amp hour), or the amount of charge it can transfer if it was given a steady supply of one ampere current for an hour.
What isn’t stated, however, is that this rating is made when the batteries are at a specific temperature, commonly around 77 Fahrenheit (25 degrees Celsius).
If the battery isn’t at the specific temperature it was rated at, then there will also be changes to the rating and the battery’s performance. If it’s too hot, it will result in the battery’s lifespan being lowered. If it’s too cold, then the usable amp hour capacity will decrease (however, the battery’s lifespan will be longer).
This is the reason why most RVers prefer keeping their rig cool.
The temperature outside can directly affect battery temperature, and by extension the battery capacity as well.
For every 15ºF increase in temperature above the 77ºF threshold, the lifespan of your batteries will be decreased by half, and the battery capacity go up by 10%
On the other hand, every 15ºF lower than 77ºF will do the exact opposite. There will be a 10% decrease in the battery capacity, but the battery life will increase.
In short, depending the temperature outside (whether it’s freezing cold or burning hot), the capacity of your house batteries will vary as well.
TEST YOUR USAGE AT DIFFERENT TEMPERATURES
So what’s all this talk about temperature for? Because as already stated, the capacity of your house batteries can vary depending on the ambient temperature. Therefore, the only way to make sure how much solar power do you need is to do what you normally do every day.
Long story short, just use the 12-volt electrical system of your RV with your usual routine and never plug it into a generator or solar power system, or even shore power.
This will give you the amount of power you typically consume. But since ambient temperature changes with the season, this will only be an approximation at best.
FIND OUT HOW MUCH POWER YOU CONSUME
To do this, you will first need to find out the rating of your house batteries in amp hour. Hopefully this can be accomplished by checking your battery to see if it’s listed there.
In the event that it’s not listed on the battery itself, here is how you can check for the amp hour rating of your batteries.
First of all, you need to find out two things: voltage of the batteries in your house battery bank (are they 6-volt or 12-volt?), and the amp hour rating of individual battery.
FIND OUT THE BATTERY MAKER AND THE PART NUMBER
You can look at the battery label located at either the top or the sides of the battery or batteries. This will contain both the manufacturer and the battery part number.
However, chances are that there won’t be any information there regarding the voltage or the amp hour rating of the battery or batteries.
So to find those out, you’ll have to use the internet.
You can input the battery maker and the part number into the search bar. This will show you a page with the battery specifications. This page will also contain the voltage and the amp hour rating of your battery.
Find the words ‘Ah @ 20hr’ or ‘20HR rating’, or something along those lines. It will refer to the amp hour rating of the battery after 20 hours of use.
This is normally what people in the industry refer to when they talk about the amp hour rating of a battery.
FINDING TOTAL AMP HOURS RATING OF YOUR ENTIRE BATTERY BANK
If your entire battery bank consists of only a single battery, then it’s easy. Whatever the amp hour rating at 20 hours (the Ah @ 20hr stated on its battery specification page) is the amp hour rating of your battery bank!
However, if you have multiple batteries, then it can be a bit more complicated. For the purposes of this explanation, we will assume that your battery bank is composed of two batteries.
The first thing you need to know is the connection between the batteries. Is it series or parallel? One trick of finding out which is to find out whether your batteries are 12-volt or 6-volt.
If your battery bank consists of two 12-volt batteries, then their connection will be parallel. If the two batteries are 6-volt, then they are probably connected in series.
This is always true as long as you have two batteries.
To calculate for the amp hour rating of your entire battery bank, there is something important you must keep in mind:
When batteries have a series connection, the voltage of the battery bank will double, but the amp hour rating will not change. On the other hand, if the connection of the batteries is parallel, the amp hour rating is what doubles, while the voltage will not change.
An example would be having two 6-volt batteries each with an amp hour rating of 210 amp hours being connected in series. The resulting battery bank will have double the voltage at 12 volts, but the amp hour rating will remain at 210 amp hours.
Another example is two 12-volt batteries rated at 75 amp hours each being connected in series. The result will be a battery bank with 12 volts of voltage and a 150 amp hour rating.
FIND OUT YOUR DAILY AMP HOUR CONSUMPTION
The easiest and most accurate way to find out the amount of energy you consume is to use a battery monitor. However, this option requires you to buy a new instrument, which you will then have to install. But fret not, there is an alternative way of getting a rough estimate of your power consumption.
To get an idea of the daily amount of your amp hour power consumption, here are the things you need to do:
- Know what the amp hour rating of the battery bank of your RV. Remember that this rating is only for the ideal outside temperature (77 ºF) and will vary depending on the actual ambient temperature.
- Go out and camp at a place you normally go to and make sure that you never plug into any outside source of power like shore power, or even a solar power system.
- Go through your life with your regular electrical usage. Don’t try to manipulate it to save energy or burn energy faster. Just do what you would normally do during a regular camping trip.
- After the first 24 hours, check the battery voltage. If your rig has a gauge that can tell you the voltage, that’s alright. But another, more accurate way of checking the voltage is by using a multimeter and measuring the voltage of the battery bank directly. Below is a chart that shows you what is the equivalent charge percentage of the voltage you measured:
- If your battery bank still has more than enough juice left for another 24 hours after the first 24-hour period, then you’re free to keep going. For another day, use the 12-volt systems of your RV just like usual. Then get another reading after another 24-hour period has elapsed and once again check the battery percentage your batteries are left with.
- Keep on using the batteries of your RV until they drop to 50% charge and record the number of days that it took. If you successfully ended with your batteries close to 50% charge, then you can divide the amp hour capacity rating of the batteries by 2 to find out how many amp hours were used during the testing period. Once you get the number of amp hours used, you can then divide that number by the number of days it took to get your batteries to roughly 50% to get your amp hour usage per day. For example, taking 3 days to reach 50% of the rated capacity of a 200-amp hour batter bank (100 amp hours) means that the usage is roughly around 33 amp hours per day (100 amp hours divided by 3 days).
Lead acid batteries are the most common type of batteries used for RVs, and this type of battery shouldn’t be brought to lower than 50% charge.
Even though 40% charge is still considered relatively safe, the best practice is still to keep the charge from dropping below 50%.
This will allow your lead acid batteries to have a much longer life and will help it retain charge for longer. In short, this good practice will help in slowing down battery degradation.
Importance of Temperature
As previously discussed already, the ambient temperature affects the performance of your RV’s batteries. The ideal temperature to conduct this test should be roughly around 77 ºF. However, this is obviously not going to happen often.
Daytime will always be hotter than nighttime. Your location will always be changing, and different places enjoy different climates. Not to mention that seasons change, so the weather changes even if you never move.
So by default, this test is already inherently flawed and will probably not hold up to real life usage most of the time. However, unless you’re willing to pay for fancy battery monitors and the installation (or you’re willing to do it yourself), then this is an easy way to have a rough gauge on how much power you consume on a daily basis.
So now you know (or at least have a very rough guess) of the number of amp hours of electricity you consume every day. The next step is to find out how much solar power you’ll be needing.
To do this, we’ll have to assume that a single solar panel rated at 100 watts can generate roughly around 30-amp hours per day.
To make the discussion easier, we’ll keep on using the example earlier (the one that uses 33-amp hours per day). If we assume that your consumption is roughly the same as the example, then we can find out the ballpark in which the amount of solar capacity you need should fall into.
Given our assumption of the average power generated by a single portable 100-watt solar panel is only about 30-amp hours each day, it’s clear that a single one will not be enough to fulfill the needs of our hypothetical RV.
From this scenario, we already know that a single 100-watt portable solar panel will not be enough and that we’ll need a portable solar panel system rated at 120 watts. The prudent choice, however, is to get a portable solar panel system rated at 160 watts minimum, or even 200 watts.
At this point, you might be wondering why getting more solar power than what you expect to use is a good decision.
The answer is that we must once again remember that there are several factors that can affect the efficiency at which your solar power systems produce power.
If the skies are covered with clouds, your solar power systems will have less sunlight to work with, and its production will be nowhere near the expected output. During such days, it’s better to have more solar capacity than what’s normally necessary.
Keep in mind, however, that it’s almost impossible to have enough portable solar power systems to counter really bad weather.
If you think you’re only going to be camping in places where the weather is always perfect and beautiful, then this might not be an issue for you. Of course, the chances of that happening often is already slim, and having perfect weather all the time is practically impossible. In that case, it’s much better to invest on excess solar capacity, even to the point that you might need a roof-mounted solar power system.
Before deciding on that, though, you should try using a portable solar power system first to see how well it fulfills your needs, which can vary depending on your preferred camping style as well as power usage.
If you find yourself lacking in solar power capacity later down the road, then you can always buy another portable solar power system, or even a roof mounted one.
SOLAR PANELS: POLYCRYSTALLINE VS MONOCRYSTALLINE
In general, there are two most common types of solar cells used in portable solar panels: monocrystalline and polycrystalline.
The process of making the solar cells is what makes the polycrystalline different from the monocrystalline.
Monocrystalline (mono) solar cells are more costly compared to polycrystalline ones, but they’re also more efficient. Mono solar cells are cut out from a single ingot of silicon. Mono solar panels are smaller compared to their poly solar panel counterparts of the same wattage. This means that mono solar cells are much more efficient compared to poly solar cells. You can recognize if a solar panel is made from mono solar cells by noticing the distinct squares that look like their corners were cut off.
Polycrystalline (poly) solar cells are the cheaper option. However, they are also a bit lacking in efficiency compared to monocrystalline ones. Poly solar cells are made by melting silicone crystals and fragments together to form a giant ‘wafer’.
As already mentioned, mono solar cell systems are the more efficient of the two, running at around 15-20% efficiency. On the other hand, poly solar cell systems are only about 13-16% efficient.
Because of this, most of the high-end, high quality portable solar panel systems use monocrystalline solar cell over the polycrystalline counterpart due to the greater efficiency of the mono solar cell systems. The higher efficiency also means a much smaller size of panels, making them easier to store and to deploy.
IMPORTANT SIDE NOTE: ALWAYS KEEP YOUR SOLAR PANELS CLEAN!!!
When we talk about efficiency of your solar power systems and solar panels and controllers and whatnot, the assumption is always that your solar panels are functioning at 100% efficiency.
As already mentioned, there are several factors that can affect the production rate of solar panels.
One of them is the cleanliness. Clean solar panels are working at 100% efficiency, and dirt can reduce that. Always keep them spotless to ensure that they’re providing the power you expect them to.
If your solar power system is ground mounted, then they’re relatively easy to clean. If what you have is a roof mounted solar power system, however, then the solar panels will be a bit harder to reach.
In order to do so, you might even need a folding ladder to reach the roof mounted solar panels.
Mono Solar Cells
- More efficient (though the difference is not exactly significant)
- A single system is much smaller in size compared to its poly solar cell system counterpart
- Darker in color (black)
- More expensive
Poly Solar Cells
- Pricing is lower compared to a mono cell system
- Color is more of blue than black
- Poly Solar cell systems are bigger compared to mono cell systems of the same capability
- Lower efficiency (however, the difference may be negligible)
So which one will you choose? The efficient monocrystalline or the cheaper polycrystalline? The best choices for a portable solar panel are all made with monocrystalline solar cells.
Additionally, the solar power systems that use panels made from poly solar cells are generally cheap. But aside from the less efficient solar cells, they also have lower quality controllers, badly sized wiring, and the frame and legs are often made from cheap materials.
Therefore, if you really want to invest on a long-term portable solar power system, get one with panels made from monocrystalline solar cells.
ECLIPSE VS LEGACY
Eclipse solar panels are more efficient than legacy panels, so they are smaller in size and lighter, as well. However, they are also more expensive.
So what are solar charge controllers?
A solar charge controller is what regulates the voltage that comes from the solar panels before it goes to the house batteries of your RV.
The controller will keep track of what the house batteries’ voltage is at, and then the controller will make sure that the voltage entering the batteries from your solar panels will match the current state of charge of your batteries.
DIFFERENT TYPES OF SOLAR CHARGE CONTROLLERS
Just like solar cells, there are also two types of solar charge controllers, pulse width modulation (PWM) and maximum power point tracking (MPPT).
PWM controllers are cheaper however they are not as efficient as MPPT controllers.
In general, the controllers that come with portable solar panel systems are PWM controllers, so that’s what we’ll be focusing on.
As already mentioned, PWM charge controllers are not the most efficient choice for converting the solar power gathered by your solar panels to another form that can be used as power by your batteries. In general, PWM controllers are only around 75-80% efficiency, compared to the 94-98% efficiency of MPPT controllers.
The reason behind this is the way they work. PWM controllers just take the voltage from the solar panels and just reduce it to a point which the batteries can handle without getting overcharged.
Obviously, this method means that the power produced by the solar panels is reduced.
If your system has low wattage, just like most portable solar power systems made for RVs, this inefficiency is necessary for keeping the overall price of the system lower. While MPPT solar charge controllers are obviously more efficient, they are also considerably more expensive and that may not always be worth it.
However, if you’re dealing with bigger solar power systems (which also have higher wattage), the power lost due to the inefficiency of using a PWM controller stops becoming negligible. In cases like this, MPPT controllers are more commonly used. This is also because as the solar power system grows bigger, it also becomes more expensive, so the cost of having an expensive charge controller becomes less significant compared to the overall price of the whole system.
Charge Stages of Solar Controllers
Solar controllers have stages that mark the actual voltage being used to charge the batteries of your RV. The three basic stages (or 3-stage charger) are the following:
- Bulk Charge – All of the power available from the solar panels will be used to charge your batteries until the voltage reaches 14.4 to 14.6 volts (also known as absorption voltage).
- Absorption Charge – Once the absorption voltage is achieved (14.4 to 14.6 volts), the charge controller will begin the absorption stage. When this point is reached, the battery should be charged at around 85% of full capacity. At this stage, the charge controller will maintain the voltage at 14.4 to 14.6 volts (absorption voltage) for roughly one to two hours. However, both the exact voltage and the duration of the absorption charge may vary depending on the manufacturer of your solar charge controller.
- Float Charge – After the necessary time is over, the absorption charge will be completed, and your RVs house batteries should be almost full. At this point, your solar charge controller will reduce the voltage of the battery charge to around 13.2 to 13.7 volts (exact voltage varies depending on the manufacturer). This lower voltage will then be held for the duration of the whole solar day. The reduced charge voltage is for making sure that the batteries don’t get overcharged, as well as protect the battery acid from boiling off. If the load on the batteries is pressured due to excessive power consumption, the controller will no longer be able to keep the battery charge level at float charge mode. When this happens, the bulk charge mode will kickstart to increase the voltage supplied to the batteries. If there is enough solar power produced by the solar panels, the house batteries will keep receiving voltage until it gets fully charged again.
The three charge modes listed above are used by all the solar charge controllers available on the market today in order to charge batteries properly. However, there is another mode named “equalization”. This is technically not a charging mode, and it used to be just called “equalizing the batteries”. However, later on, it was decided that it should be the fourth charging mode.
In Equalizing mode, the batteries get charged in the neighborhood of 14.8 to 15.5 volts (once again, exact voltage depends on the manufacturer). This results in the overcharging of the batteries and the gassing of its cells. The purpose of this process is to ensure that the cells of the battery bank all have an equal charge.
In general, equalization should be done every four weeks. However, some charge controllers automatically initiate equalization mode whenever the voltage of the battery bank dips under a specific level (normally 10 to 12.1 volts, once again depending on the preference of the manufacturer and their idea of what is right).
Equalization should only be done if your battery bank is made of flooded, wet cell lead acid batteries unless the manufacturer says that it’s alright even if what you have is gel led acid batteries or AGM batteries.
To get the specific voltages and duration for each charging stage, check the specifications of your solar charge controller.
SOLAR CHARGE CONTROLLER DISPLAY
If your solar charge controller is on the high-end side of the market, then it will probably have an LCD or a digital display that shows you exactly what your controller is doing and what’s happening to your batteries.
Additional information that can be displayed includes voltage, amperage, and even power usage, as well as many other info that you will most likely never need.
Sometimes there will also be LEDs used to indicate the charge mode and other such details.
Of course, the cheaper controllers will only have LEDs, but at the very least they’re still capable of charging your battery bank.
WATERPROOF SOLAR CONTROLLERS
Another important detail to take note of is whether your charge controller is waterproof or not. Nowadays, both Zamp and Renogy use waterproof controllers for their portable solar panels.
If you have a controller that isn’t waterproof, you must be careful when using it, as well as make sure that it’s not exposed during wet weather.
MONITORING OF YOUR BATTERY
Some high-end controllers can monitor the voltage and even the temperature of your battery bank directly.
This information can be useful in preventing the batteries from overcharging or overheating.
While a nice feature to have, it’s not something everyone needs, so don’t put it up too high in your list of priorities,
MAKE SURE YOUR CHARGE CONTROLLER AND BATTERY TYPE ARE COMPATIBLE
Portable solar panel systems come with charge controllers that can be used with gel, flooded and AGM lead acid batteries.
If your batteries are lithium ion, then you’ll need to get another controller which should be compatible with lithium batteries.
ELECTRICAL CONNECTORS FOR YOUR SOLAR PANEL
You should also find out the electrical connectors of your solar power system of choice.
However, this is not very important since it can easily be dealt with by changing by electrical connectors.
What’s important is that you know what electrical connectors your system has so you know whether you can just plug it in as it is or if you need the connector ends need changing.
It’s also useful in the event that you want to use an extension cable to increase the range of deployment of your portable solar power system. You need to know the type of connectors of your system in order to buy the correct extensions (they have to be compatible).
There are four common connectors that are most often used by manufacturers. These are the MC4, SAE, Anderson, and no connectors (which uses alligator clips).
Just make sure that your connectors are compatible. In the worst case scenario, you can always just switch them out.
Having solar power systems is a great way of making sure that your RV never runs out of juice, even while boondocking. In general, the amount of power you need will decide which system is best for you.
At this point, you should be mostly educated on how to choose the right portable solar panel best suited for your needs.
If you’ve finally decided to pull the trigger and are now in the market for your first solar power system, or if you decided that what you currently have is not sufficient and you want to add more, here are some suggestions from us and why you should pick them.
All the brands shown below are also tried and tested.
Which RV Solar Panel brand to get?
The manufacturer of your solar panels is an important factor, it’s better to get yours from an established brand well-known for making quality products. Here are three manufacturers that will surely get the job done.
Zamp is an industry-leading manufacturer and for good reason. Their product line is wide and varied, with different panel sizes depending on your needs. Their portable solar panels are always durable and of high quality, guaranteed to give you what you require. However, all this comes at a price: Zamp is also the most expensive brand among the three.
While their selection is not as big as Zamp’s, Renogy still offers great products of high quality. Even better, their products are generally cheaper compared to Zamp.
Eco-worthy’s products aren’t the best quality, but they’re not the worst either. More importantly, they are very affordable and will always get the job done.
COMPARISON OF THE BEST PORTABLE SOLAR PANELS
|Features||Best Portable Solar||Best Bang-for-Buck Solar||Best Solar Panel at a Budget|
|Wattage||80, 120, 160, 200||100, 200||120|
|Digital Display on the Controller||Yes||Yes||No|
|Number of Charging Stages||5||4/5||3|
|Adjustable Panel Tilt Angle||Yes||Yes||No|
- The Zamp Solar Portable packs a big punch with a staggering 6.84 amps, large enough to handle larger battery banks.will perform up to 30-40 amps per day.
- The system has been designed to work well with dual 6 volt or 12 volt battery systems, this system will perform up to 30-40 amps per day.
- Monocrystalline solar cells
- Manufactured in USA
- Waterproof controller
- PWM solar charge controller
- Controller has a digital display
- 5 Charging stages
- Wide range of wattage
- Best quality in construction
- Adjustable tilt angle
- Comes with a carrying case
If you’re in the market and you want the best of the best, regardless of the price, then look no further than Zamp and their portable solar panels. From the construction, to the quality of materials, to the features packed, there is no question that this is the best solar panel you can buy on the market.
The only problem is the price. Zamp’s offering costs almost twice the price of Renogy’s portable solar power systems. The only question is whether the extra features and better quality makes up for the price.
However, that’s something only you can decide. The fact is that what Zamp offers with their portable foldable solar power system is much better than the competition. Zamp also offers a wide range of choice when it comes to wattage rating, which is a good option to have.
Just keep in mind that if you’re the type to go boondocking often, whatever choice you get, your solar power system will eventually pay for itself with the gasoline for the generator and fees for campgrounds that you no longer have to pay for.
- Compatible with gel, sealed, Lithium, and flooded batteries.
- Excellent performance in low-light environments, alligator clips for ease of connection. German-made Solar cells. Protective casing. The low-voltage system avoids electric shock hazards.
- Monocrystalline solar cells
- Perfect balance between the quality and performance of the product and its price
- Waterproof controller
- PWM solar charge controller
- Digital display on controller
- Has 4/5 charging stages
- Adjustable panel tilt angle
- Comes with a carrying case
- Construction quality not quite as amazing as Zamp’s
If you’re in the market for something that will last you a long time but doesn’t break the bank, then Renogy is perfect for you.
Of course, Renogy’s portable solar panels are not as good as the ones offered by Zamp, but the lower pricing is a good compromise for the features lost. Despite not being the best, Renogy is still more than adequate to fulfill your needs. This combination of good quality and lower pricing makes the Renogy portable solar panels the perfect choice for a vast majority of RVers.
Renogy only offers their panels in 100-watt and 200-watt ratings. However, they’re all made from monocrystalline solar cells.
The 100-watt version can be bought in both the older legacy panel as well as the newer Eclipse Panel. The 200-watt version is only available with the Eclipse panel and doesn’t come with its own solar charge controller.
- Ideal Daily Output: 500W (depending on the availability of sunlight).
- Basic component for off-grid solar panel system, caravan, RV, boat, Green house solar panel system.
- Monocrystalline solar panels
- Aggressive pricing
- Perfect for people who don’t use solar power often
- No display on the charge controller
- Does not come with a carrying case
- No way of adjusting the tilt angle of the panel
- Lackluster construction
Eco-worthy’s portable solar panels are a cheap way of getting solar power. However, whether the lower price is worth the tradeoffs is debatable. The construction is not as good, so it might not last as long. Solar panels generally pay for themselves over time, but they if they break too quickly, which might be the case for this portable solar power system.
However, if you’re only looking for something cheap because you don’t feel like you’ll need to use it often, then this product is good for you. Just remember that it doesn’t come with a carrying case which, combined with the flimsy construction, means you have to take extra care when using this solar panel. Its controller also lacks a digital display which could be a deal breaker for some.
Having a portable solar power system is great because it allows you to charge the battery bank of your RV for free.
Portable solar power systems are not for everyone. However, if you’re the type to go boondocking often, or prefer camping off-grid for extended periods of time — to the point where your batteries get drained just from daily use — then having a portable solar power system is perfect for you.
Additionally, solar power is a great alternative to using a generator, so you can say goodbye to the annoying noises that your generator… generates (heh).
Since you already know all there is to know about how to choose the perfect portable solar panel for your needs, all you need to do now is apply what you’ve learned and get the panel most suited for you.
OTHER THINGS YOU MAY WANT TO KNOW ABOUT
Solar panel extension cables
One of the reasons why portable solar panels are better than roof mounted solar panels is because you can mount them on the ground directly under the sun while your RV is cooling under the shade.
However, the standard power cord that comes with your portable solar panel may not be enough to do this. In that case, all you need to do is buy a solar panel extension cable.
Most extension cables on the market right now have an MC4 connector on both ends. If you have a Renogy portable solar panel, then an MC4 connector is already compatible with your solar power system.
Zamp, on the other hand, uses SAE connectors on their portable solar panels.
When choosing an extension cable, all you need to do is make sure they’re compatible with your portable solar panels and that of course their lengths are sufficient enough for your needs.
Easy portable solar panel hold down
Because portable solar panels are deployed on the ground, they’re susceptible to being affected by strong winds.
If a sufficiently strong wind hits the back of your solar panels, they can easily get flipped over which can cause damage.
To prevent this from occurring, all you need to do is to set up a system to hold down your solar panels.
If your portable solar panels have the leg set-up of Renogy, then you’ll need a metal rod and a full 5-gallon water jug.
Place the metal rod on top of both legs and then place the filled 5-gallon water jug directly on top of the rod.
If your portable solar panels have legs like the ones made by Zamp, then you’ll only need the full 5-gallon water jug, which you’ll then place on the built-in horizontal support.
If you want to be precise about the amount of power that you use on a daily basis, which can also help in figuring out how much solar power do you need, then you can always use a battery monitor to make your life easy.
Battery monitors measure the exact amount of electrical current that flows in and out of your batteries.
Not only will this help you find out exactly how much solar capacity you need, but it can also help you check whether your batteries are still in top shape or if they’ve started degrading.
Solar Battery Maintainers
Solar battery maintainers help in keeping your RV’s house batteries fully charged even while there’s no shore power to connect to.
Even when not in use, the batteries of your RV are always getting drained slightly unless it’s plugged in. Solar battery maintainers prevent this even without needing a shore power.
When choosing a solar battery maintainer, always be wary of cheaper products. They may not be able to provide enough juice to keep your house batteries at full capacity. Or their solar charge controller may be the cheap sort which can even lead to damage to your batteries.
Solar Battery Maintainers can either be permanently mounted or have legs for less permanent deployment.