Charge Your RV Batteries With A Portable Solar Panel Charger When Boondocking/Dry Camping
I use a 100W Renogy suitcase solar panel to keep my RV batteries charged while boondocking. It’s impressive how much power you can generate on a sunny day, even in winter.
Your RV battery powers essentials like 12V lights, a TV (if it’s 12V), the bathroom fan, and the water pump when you’re off-grid. While campgrounds charge your battery via shore power, boondockers rely on gas generators or solar panels for recharging.
Related Post: How Good Is A 170W Solar Panel That Costs Less Than $100?
Why Choose Portable Solar Panels?
Portable panels are great for beginners or those who don’t want to mount panels on their RV roof. With built-in stands, they’re easy to set up and can be placed in the sun even if your RV is parked in the shade.
If your RV has a quick-connect port, make sure it’s compatible (e.g., Zamp or Furrion). I recommend reading this article if it’s a Zamp solar port, or this article if it’s a Furrion solar port.
Key Tip: Always use a solar charge controller between the panel and the battery. It is a necessity to make sure the battery is charged safe and properly. The products I recommend below include one, but double-check if you’re considering other options.
For more details, including FAQs about solar panels, accessories, and monitoring your batteries, scroll down or leave a question in the comments—I’m happy to help.
Now, let’s dive into today’s comparison of portable solar panels.
Product Summary (Links to Amazon)
- Acopower 60W Foldable Panel
- Most Portable – ECO-WORTHY 120W Foldable Solar Panel
- My Choice – Renogy 100 Watt Suitcase
- Most Features – ACOPOWER 120W Portable Foldable Suitcase
- Most Watts – Renogy 200 Watt Eclipse
Most Portable
My Choice
Most Features
Most Watts
Last update on 2025-03-18 / Affiliate links / Images from Amazon Product Advertising API
Best Portable Solar Panels Reviewed
1. Acopower 60W Foldable Panel
The Acopower 60W solar panel is a portable option made from two efficient 30W monocrystalline panels. It includes a 10A solar charge controller to protect your 12V RV batteries from overcharging.
Why Choose the Acopower 60W?
- Lightweight and Portable: Its 60W size makes it more manageable than heavier 100W panels.
- Built-In Kickstand: Allows you to angle the panel for optimal sun exposure, especially helpful during mornings, evenings, or winter camping.
- Travel-Friendly: Includes a carrying bag and handle for easy transport and protection.
- Bypass Option: Can bypass the charge controller to connect directly to a solar generator.
- Connectivity: Use an MC4 to SAE adapter for Zamp ports or an MC4 to 2-pin adapter for Furrion quick-connects.
The solar charge controller isn’t waterproof, but the panel is sturdy and durable, with built-in fused alligator clips for safe battery connections.
Who Is It For?
The Acopower 60W is perfect for campers looking for an easy, reliable way to keep their RV batteries charged while boondocking. It’s ideal for running essentials like water pumps, 12V lights, fans, and TVs, allowing for extended stays off-grid.
PROS
- Foldable and portable
- Built-in bypass for solar generators
- Kickstand built-in
- 10A Charge controller
- Includes carrying case
- Monocrystalline panels
CONS
- Heavy compared to flexible solar panels
2. ECO-WORTHY 120W Foldable Solar Panel
The Eco-Worthy 120W foldable solar panel is an excellent choice for RV travelers, vandwellers, and car campers who want portability and efficiency without the need to mount panels permanently.
Why Choose the Eco-Worthy 120W?
- Built-In Solar Charge Controller: Safely charges 12V RV or car batteries, preventing overcharging.
- Direct Connection Option: Bypass the charge controller to connect directly to solar generators.
- Lightweight Design: Weighing just 8 lbs, it’s easy to transport and set up.
- High Efficiency: Generates ~70-80 watts in optimal conditions, enough to recharge a 100Ah battery from 50% in about 8 hours.
- USB Ports and DC Adapters: Charge phones, tablets, and small devices via USB or use the included 8 DC adapters for versatile connections.
Who Is It For?
The Eco-Worthy 120W is ideal for those who want a portable, efficient, and easy-to-use solar panel. It’s perfect for off-grid camping, especially if you park in shaded areas, as you can place the panel in the sun. Its portability also makes it great for winter camping, where angling the panel toward the low horizon sun significantly boosts efficiency.
Related: Best 12 Volt RV Lithium Battery Reviews + How To Charge
Lightweight, portable, and versatile, the Eco-Worthy 120W is a reliable companion for anyone looking to harness solar power on the go.
PROS
- 20A PWM Charge Controller with USB port
- 10 feet wiring
- Several different DC outputs
- Folds and becomes very portable
- Handle
CONS
- Nothing particular
3. Renogy 100W Suitcase
The Renogy 100W portable solar suitcase is a trusted choice for RV travelers and campers who want an efficient, durable, and portable solar solution. Renogy’s reputation for quality makes this panel a standout option for off-grid adventures.
Why Choose the Renogy 100W Solar Suitcase?
- Built-In 20A Waterproof Charge Controller: Safely charges gel, sealed, lithium, and flooded lead-acid batteries while displaying performance metrics like amperage.
- Bypass Option: Some newer models include a pre-wired bypass, making it easy to connect directly to solar generators like the Goal Zero Yeti 1000X.
- Portable and Durable Design: Includes a kickstand for sun angling, a handle for easy transport, and a sturdy carrying case for travel.
- Flexible Connectivity: Comes with 10-ft alligator clips for 12V batteries and supports adapters like:
- MC4 to SAE adapter for Zamp solar ports.
- MC4 to 2-pin adapter for Furrion solar ports.
- Extension Options: Extend the included cables with WindyNation 20-ft MC4 extension cables for added flexibility.
Who Is It For?
The Renogy 100W solar suitcase is perfect for those seeking a plug-and-play solar setup that’s easy to transport and set up. It’s especially useful for RVers, vandwellers, and campers who want reliable power to keep 12V batteries charged without committing to a permanent roof-mounted system.
For added efficiency, consider the Renogy Eclipse 100W, a similar model featuring more advanced solar cells.
With its durability, portability, and flexibility, the Renogy 100W portable solar suitcase is an outstanding choice for off-grid power.
PROS
- 20A waterproof charge controller
- 10 ft alligator clips cable
- Robust handle
- Built-in kickstand
- Monocrystalline panels
- Carrying case included
CONS
- Heavy compared to flexible solar panels
4. ACOPOWER 120W Portable Foldable Suitcase
The Acopower 120W portable solar panel builds on the functionality of their 60W model, doubling the wattage while remaining portable, lightweight, and easy to store.
Why Choose the Acopower 120W?
- Efficient Design: Made up of three foldable 40W monocrystalline panels, it folds nearly flat for easy transport and storage.
- Built-In Bypass: Allows direct connection to solar generators.
- 10A Charge Controller: Features two USB ports for charging phones, tablets, and small devices directly.
- Kickstand and Versatility: Comes with a kickstand for optimal sun angling, but can also be placed on the ground or hung up.
- Portable and Easy to Use: Includes SAE to alligator clips, extension cables, and a built-in storage bag with a handle for effortless carrying and setup.
Who Is It For?
The Acopower 120W is perfect for RV campers, car campers, and boondockers who need reliable, lightweight solar power for charging batteries and devices. Its portable design makes it ideal for travelers who value convenience but need enough power to support essential off-grid needs.
It is a highly portable, feature-packed solar charger that excels in efficiency and ease of use.
PROS
- 120W solar power
- Monocrystalline panels
- Stand
- Bag to store cables in
- Handle
- 10A charge controller with USB ports
- Built-in bypass for solar generators
- Lightweight
CONS
- Not waterproof
5. Renogy 200 Watt Eclipse
The Renogy 200W Eclipse Solar Suitcase is a larger, more powerful version of the Eclipse 100W kit, designed for those who need higher efficiency and more wattage while remaining portable and easy to use.
Why Choose the Renogy 200W Eclipse?
- High Efficiency: Features two 100W monocrystalline panels with excellent build quality and performance.
- Voyager Waterproof Charge Controller: Displays battery voltage, incoming amps, and includes temperature and voltage sensors for easy monitoring.
- Durable and Portable Design: Comes with a rugged carrying case, locking latches for safe storage, and plastic edge protectors for added durability.
- Adjustable Aluminum Stand: Lightweight at 36 lbs and easy to adjust for optimal sun exposure throughout the day.
- Plug-and-Play Setup: Includes 10 feet of wiring and alligator clips for simple connection to RV batteries.
Who Is It For?
The Renogy 200W Eclipse is perfect for RVers and campers who want a powerful, portable solar kit to maintain a healthy battery charge. It’s ideal for those with higher energy needs or larger setups, but still value portability and ease of use.
Pro Tip: Pair this system with a 100Ah AGM battery and an inverter for a complete solar setup capable of powering multiple RV appliances.
The Renogy 200W Eclipse Solar Suitcase is my top pick for portable solar panels this year, offering a robust, efficient, and reliable solution for keeping your batteries charged off-grid.
PROS
- 200W
- Adjustable stand
- Waterproof 20A charge controller with 4-stage charging
- Temperature and voltage sensor
- 10 feet wiring
- Rugged carrying bag
- Robust handle
- Monocrystalline panels
CONS
- Should include extension cord for this price
Conclusion And Portable Solar Panel Recommendations
If you’re unsure how many watts or panels you need, check out the considerations and FAQs below. The best option is the one that meets your needs—no more, no less.
See Also: The New EcoFlow Delta 2 Tested & Reviewed
That said, I always recommend getting more solar than you think you’ll need. Sunny conditions won’t be perfect every day—some days, you’ll rely on energy stored from previous days, and others, you might only get an hour of sunlight before a storm rolls in.
Here are my top solar panel recommendations.
Most Versatile: ACOPOWER 120W Portable Foldable Suitcase
The Acopower 120W solar panel is lightweight, portable, and impressively powerful.
With a kickstand, USB-equipped charge controller, cable storage bag, handle, and built-in bypass for charging solar generators, it’s thoughtfully designed for boondockers. Acopower has truly nailed the essentials with this panel.
Best For Charging RV Batteries: Renogy 200 Watt Eclipse
I wouldn’t go beyond 200W with portable panels—for anything more, roof-mounted panels are more practical.
If you want the best portable option for quickly charging 12V batteries, this 200W kit is it. With high-efficiency monocrystalline panels, adjustable legs, a waterproof charge controller, and a rugged carrying case, it’s the top plug-and-play system available.
A 100W version is also available for smaller setups.
What To Consider When Buying Solar Panels
When shopping for a portable solar panel there are a few things to consider. Let’s name a few.
Wattage
The wattage you need depends on your energy usage.
- Low Usage: If you’re running only 12V lights and a bathroom fan for an hour a day, a 100W panel might be enough.
- Moderate Usage: For daily use of a 12V TV or similar devices, 200W or more is recommended.
Even on cloudy days, a 200W panel will outperform a 100W panel, producing roughly double the output, even if it’s not much in absolute terms. This extra capacity can make a big difference in less-than-ideal conditions.
Weight
If you frequently set up and pack away your panel, weight is an important factor. Portable panels are often heavier than expected, so check the weight to ensure it’s manageable. For panels left out long-term, weight may not matter as much.
Cord Length
If you park in the shade, a longer cord will be necessary to reach your battery. However, longer cables cause more power loss, so keep the wire as short as possible between the panel, charge controller, and battery for better efficiency.
DIY Solar Panel System vs. Plug-and-Play: What You Need to Know
If you’ve browsed forums or talked to solar enthusiasts, you’ve likely heard the advice: “Just build your own solar panel system—it’s cheaper!” While that’s true in some cases, DIY setups require time, effort, and a basic understanding of solar components.
For beginners or those with limited free time, plug-and-play systems are a great alternative. They may cost more upfront, but they save you the hassle of sourcing parts, figuring out compatibility, and assembling everything. However, if you enjoy hands-on projects and want to save some money, a DIY system can be a rewarding way to power your RV or camper off-grid.
Why DIY Solar?
A DIY setup gives you full control over every component, allowing you to customize the system to your exact needs. You can upgrade individual parts over time, and if something breaks, you’ll know how to fix it. Plus, it’s a great way to learn more about solar power and how your RV’s electrical system works.
That said, a DIY approach requires research. You’ll need to understand key concepts like series vs. parallel wiring, how to calculate wattage and amperage, and why using the correct wire gauge and fuses is critical for safety. If this sounds overwhelming, a plug-and-play system might be the better option.
What You’ll Need for a DIY Solar System
Solar Panels (Essential):
Solar panels are the heart of your system. I recommend 100W 12V monocrystalline panels, such as the Renogy 100W Compact Panel, for their lightweight, high-efficiency design. Your next question might be how many panels you should get.
Two panels are ideal for beginners, as they pair well with most entry-level charge controllers. For more panels, you’ll need to upgrade the controller and wiring to handle the extra power.
Solar Charge Controller (Essential):
A charge controller regulates the voltage from your panels to protect your battery. The Renogy Voyager 20A is a great choice for small systems.
This controller works with most battery types and includes a display to monitor voltage and amps.
You can also go with this model by Acopower which is already wired and ready to be connected to solar panels and a battery using alligator clips.
Stand (Optional):
While you can lean your panels against a bucket, an adjustable stand like this adjustable solar panel mount makes setup easier and improves efficiency by allowing you to angle the panels toward the sun.
Fuses and Safety Components (Essential):
Fuses are critical for preventing electrical fires and protecting your components. Place them between the panels and charge controller and between the charge controller and the battery.
Cables and Connectors:
Choose cables based on your setup. If you buy the Renogy charge controller that doesn’t include wiring, you’re going to need MC4 to bare wire cables to connect the solar panel to the charge controller. Renogy sells these (click to view on Amazon).
Now you need cables to connect the battery to the solar charge controller.
If you want to set up a more permanent installation, use these types of cables by Renogy.
For a more portable setup, use this type of cable by Newpowa that comes with alligator clips.
For parallel wiring of two panels, you’ll need MC4 Y Branch Connectors.
If your charge controller is far from your panels or battery, use an MC4 Extension Cable.
How To Connect the Parts Above
1. Connect Charge Controller to Battery
The first step is connecting the charge controller to your battery. Ensure your battery is sealed, gel, lithium, or flooded. Check the label to confirm the type and configure the charge controller accordingly (refer to the product manual). The controller must be connected to a battery before making changes, but it’s safe to do so since the solar panel isn’t connected yet.
Prepare the Charge Controller:
Locate the four connection points on the controller:
- Two for the solar panel (positive
+and negative-) - Two for the battery (positive
+and negative-)
Attach the Battery Wires:
- Use a screwdriver to connect the wires.
- Red = Positive (
+) and Black = Negative (-). Don’t cross these connections.
Attach the Solar Wires:
- Use a screwdriver to connect the wires.
- Since the Renogy solar panel I recommend above comes with a positive MC4 male connector, we must match it with an MC4 female connector. So you must connect the wire with the MC4 female connector from the Renogy cable kit to the positive solar panel connection point on the charge controller.
- Then connect the wire with the MC4 male connector from the Renogy cable kit to the negative solar panel connection point.
Permanent Installation To the Battery:
If using a cable with terminal rings like this one by Renogy, connect the red cable to the battery’s positive terminal and the black cable to the negative terminal.
Using Battery Clamps To Connect Charge Controller to Battery:
- Connect the Newpowa wire with alligator clamps cables to the battery connection points on the charge controller. Make sure you connect positive to positive (red) and negative to negative (the black alligator clamp, which seems to have a blue wire).
- Clip the clamps to the battery terminals, starting with the red positive clamp.
Once connected, the charge controller should power on, allowing you to set the battery type.
2. Connect Charge Controller To Panel
Steps for Single Panel Setup:
- Plug the positive MC4 male connector from the panel into the positive MC4 female connector, if you followed my instructions above using the Renogy cable kit.
- Plug the negative MC4 female connector into the negative MC4 male connector.
- I recommend installing a Renogy 20A inline fuse on the positive connection for added safety.
Steps for Two Panels (Parallel Connection):
If you’re using two panels, connect them in parallel with Renogy MC4 Y Branch Connectors.
Combine Positive Wires:
- Connect the positive wire from each panel into the Y branch connector’s positive input.
- Plug the output of the Y connector into the positive MC4 female connector connected to the charge controller.
Combine Negative Wires:
- Connect the negative wire from each panel into the Y branch connector’s negative input.
- Plug the output of the Y connector into the negative MC4 male connector connected to the charge controller.
Parallel Connection Benefits:
- Voltage remains constant (e.g., 12V or 18V under load).
- Amps are additive (e.g., two 12V panels rated at 5A each will output 12V and 10A).
3. Place Solar Panels in the Sun
Position your panels in direct sunlight and start generating power. This completes the most basic setup for off-grid solar.
Next Steps: Add an Inverter
To run standard 120V AC appliances in your RV, add a pure sine wave inverter like the Renogy 1000W Pure Sine Wave Inverter.
Inverter Installation:
- Install an inline fuse between the battery and the inverter for safety.
- Connect the inverter to the battery, matching positive (
+) and negative (-) connections.
With this setup, you can power your RV appliances directly from your solar-charged batteries.
Frequently Asked Questions About Solar Power And Solar Panels
How Much Solar Power Do You Need?
The amount of solar power you need depends on your daily energy usage. Here’s a simplified way to calculate it.
Step 1: Measure Energy Use
Use a tool like the Poniie PN2000 Electricity Usage Monitor to measure the wattage of your appliances. For safety, don’t plug in anything over 1900W, like an air conditioner.
Make a list of your appliances and their wattages. Convert watts to amps for 12V systems by dividing watts by 12. For example:
- A 900W microwave uses 75 amps per hour (900 ÷ 12 = 75).
Below is a table I made of our electricity needs and the amperage each device requires.
Step 2: Estimate Battery Capacity
Your battery’s usable capacity determines how long you can run your appliances before needing to recharge. Here’s how to calculate it:
- Find the Battery’s Amp-Hour (Ah) Rating: Check the battery label for the Ah rating. If it’s not listed, look for the Reserve Capacity (RC), often labeled as “minutes @ 25 amps.”
- Convert RC to Ah: Divide the RC by 2.4. For example: A battery with 120 RC at 25 amps = 50Ah usable capacity (120 ÷ 2.4).
- Determine Usable Capacity:
- Lead-Acid/Deep-Cycle Batteries: Use only 50% of the total capacity to avoid damage. A 100Ah battery = 50Ah usable capacity.
- Lithium Batteries: Typically allow 80% usage. A 100Ah lithium battery = 80Ah usable capacity.
See Also: How Long Will An RV Battery Run The Furnace? + Calculations
Example: TV Usage
Let’s say you have a 12V battery rated at 100Ah and want to run a TV using 5 amps/hour:
- Calculate Safe Usage: Usable capacity = 50Ah (50% of 100Ah for lead-acid).
- Calculate Runtime: 50Ah ÷ 5 amps = 10 hours of runtime.
- Adjust for Inverter Efficiency: If using an inverter (80% efficient), multiply the runtime by 0.8: 10 hours × 0.8 = 8 hours of TV usage.
Step 3: Calculate Solar Panel Needs
A good 100W solar panel generates about 5 amps per hour in peak sunlight. Multiply this by the average sunlight hours in your location:
Example: In Utah (5 hours/day), a single 100W panel generates 25 amps daily (5 × 5).
If you don’t know how many hours of peak sunlight you get per day in your state, see the picture below for some reference.
If your daily energy needs are 100 amps, you’ll need:
- 4 panels (400W) generating 100 amps/day in optimal conditions.
- Adding a 5th panel compensates for inefficiencies, providing 125 amps/day.
Example Setup
To power 103Ah daily (the amps required to fill my needs) with a safe 50% battery usage:
- Batteries: Two 225Ah 6V batteries (like these for example) wired in series for 12V, providing 112.5Ah usable capacity.
- Panels: Five 100W panels generating 125 amps/day in ideal conditions.
How long will it take to charge my RV battery with solar panels?
The time it takes to charge your RV battery with solar panels depends on several factors. Let’s break it down to give you a realistic understanding of what to expect.
Battery Size and State of Charge
The size of your battery plays a significant role in charging time. For example, a 12V battery rated at 100 amp-hours (Ah) will take less time to charge than a larger battery, but it also depends on how much energy you need to replace. If your battery is at 50% (50Ah remaining), your solar panels will need to provide 50Ah to fully recharge it.
Solar Panel Output
The number and efficiency of your solar panels determine how much power you can generate. For instance, two 100W panels can produce around 5 amps each in good sunlight, giving you a total of 10 amps per hour. If you get five hours of direct sunlight, that’s 50 amps—enough to fully recharge a 100Ah battery from 50%.
However, real-world conditions rarely match perfect calculations. Weather, shading, and seasonal changes can significantly reduce panel output. On cloudy days, those same panels might only produce 1–2 amps combined, drastically increasing charging time. And in winter, when the sun is lower on the horizon, even properly angled panels won’t reach their maximum potential.
See Also: How To Install Solar Panel On RV Roof & Connect To Battery
Charge Controller Efficiency
Your charge controller type matters. An MPPT controller is more efficient than a PWM controller, especially during early mornings, late afternoons, or overcast conditions. MPPT controllers optimize the power from your panels and can significantly reduce charging time in less-than-ideal conditions.
The Role of Battery Temperature
Temperature affects battery performance and charging efficiency, especially for lead-acid batteries. Here’s what you need to know:
Cold Temperatures:
- Lead-acid batteries (AGM and flooded) lose usable capacity as temperatures drop. At 32°F (0°C), a 100Ah battery might provide only 80Ah, and at 0°F (-18°C), it could drop to 50–60Ah.
- For lithium batteries, capacity is better maintained in the cold, but charging below freezing (32°F/0°C) can damage the cells unless the battery has built-in heating or protections.
Hot Temperatures:
- Batteries self-discharge faster in hot weather, meaning you lose stored energy more quickly. Prolonged heat exposure can also shorten battery lifespan.
If you’re boondocking in extreme conditions, account for these temperature effects. In cold weather, lead-acid batteries may not power your appliances as long as expected, and lithium batteries require care during charging to avoid damage.
Real-World Example
Let’s say you have a 100Ah 12V battery at 50%, two 100W solar panels, and five hours of good sunlight. Ideally, those panels generate 10 amps per hour, giving you 50 amps—enough to fully recharge your battery.
However, real-world inefficiencies, such as charge controller losses, wiring, and temperature effects, can stretch this time to 6–7 hours. If it’s cloudy or cold, it could take significantly longer. Conversely, if it’s very hot, your battery might self-discharge faster, requiring more frequent charging.
Planning for Imperfections
Solar power is incredibly useful but not perfect. Weather, seasonal changes, and battery temperature can all affect charging times. To avoid running out of power:
- Slightly oversize your solar system. Adding an extra panel can help compensate for cloudy days or reduced winter sunlight.
- Monitor battery health and plan for temperature effects. Keep batteries warm in the winter and shaded in the summer to maximize performance and lifespan.
Do Solar Panels Work When It’s Cloudy?
It depends on several factors:
- Time of Year: The sun is higher in the sky during summer, which can help panels perform better even on overcast days. In winter, the sun’s lower angle reduces efficiency.
- Charge Controller Type: An MPPT charge controller is much better at extracting power in low-light conditions compared to a PWM controller, increasing your chances of generating a few amps on cloudy days.
- Panel Quality and Type: High-quality monocrystalline panels are more efficient in low-light conditions than cheaper alternatives.
- Panel Angle: Panels angled directly toward the sun, even behind clouds, are more likely to generate power than flat-mounted ones.
That said, on very cloudy days, output may drop to near-zero. In heavy overcast or storms, it’s possible your panels won’t generate any usable power at all.
While solar panels can work in cloudy conditions, their performance depends heavily on these factors, so it’s always good to plan for variability in your system’s output.
How Do I Get the Most Out of My Solar Panels?
- Keep Them Clean: Dust, dirt, or debris can significantly reduce efficiency. If your panels are roof-mounted, check and clean them regularly, especially after storms. A quick wipe with glass cleaner can make a big difference if you notice your batteries taking longer to charge.
- Optimize the Angle: Proper angling is crucial, particularly during the winter when the sun is lower on the horizon. Adjust your panels to face the sun directly to maximize exposure and energy generation.
- Use an MPPT Charge Controller: An MPPT charge controller extracts more power in less-than-ideal conditions. It’s especially effective in early mornings, late afternoons, winter months, or cloudy weather, providing better efficiency than a PWM controller.
- Monitor Your System: Pay attention to how your system performs under different conditions. Experiment with panel angles, especially in winter or during late afternoons, to learn what generates the most amps. A monitoring system or app can help you track performance and make adjustments for optimal efficiency.
Do Solar Panels Work in the Winter?
Yes, solar panels do work in the winter, but their performance can be less efficient because of shorter daylight hours and the sun being lower on the horizon.
With less direct sunlight, it becomes more challenging for your panels to generate as much energy as they would in the summer months.
However, there are ways to improve energy production. Tilting your panels to face the lower winter sun will help capture more light and increase energy generation.
Using an MPPT charge controller can significantly enhance the system’s efficiency in low-light conditions, allowing you to generate more amps even when the sunlight is weaker. While winter solar production may not be as high as in the summer, these adjustments can help you get the most out of your system during the colder months.
Related: BougeRV MPPT Solar Charge Controller – Worth It Over PWM?
Are Solar Panels Better Than Generators?
In terms of cost, solar panels aren’t necessarily better than generators. Solar systems are an investment that can be expensive upfront, while a generator is typically much cheaper, even if you have to factor in ongoing fuel costs like gas or propane.
However, when it comes to the environment, solar panels are the clear winner in the long run.
By producing your own clean energy, you reduce your carbon footprint and contribute to a more sustainable lifestyle. Plus, when you’re camping, it’s much quieter and more peaceful without the constant hum of a generator—unless, of course, your neighbor has one!
While solar systems are still costly, the hope is that advancements in technology and reductions in manufacturing costs will make solar more affordable and competitive with traditional generators in the near future.
So, if you’re looking for a greener, quieter way to power your RV or campsite, solar panels are the better choice, even if the initial cost is higher.
What is a Solar Charge Controller and Do I Need One?
Yes, you absolutely need a solar charge controller. It plays a crucial role in managing the voltage coming from your solar panels to your battery, preventing overcharging and ensuring the battery is charged safely.
Even though a solar panel might be rated at 12V, it often produces between 16 to 20 volts when the sun is shining. Without a charge controller, that higher voltage can damage your battery. The controller regulates the voltage, ensuring it stays within safe limits, protecting your battery from harm.
Another important feature of a charge controller is its ability to prevent reverse current flow. Without this, electricity could flow back from the battery into the solar panels, essentially wasting energy. The controller solves this by opening the circuit when there’s no usable power and preventing reverse current.
Types of Solar Charge Controllers
There are two main types of charge controllers: PWM (Pulse Width Modulation) and MPPT (Maximum Power Point Tracking).
- PWM (Pulse Width Modulation): These are cheaper and commonly used in smaller systems. They’re about 70-80% efficient, as they take the voltage from your panels and reduce it to 12V to safely charge the battery. While PWM controllers are effective, they’re not as efficient at converting excess voltage into usable power. PWM controllers are typically available up to 60 amps, making them ideal for smaller solar setups.
- MPPT (Maximum Power Point Tracking): These are more expensive but 90-98% efficient. MPPT controllers convert excess voltage into amperage, rather than wasting it like PWM controllers. They also allow for higher voltage through the wires, which reduces power loss, making them a better choice for larger systems. MPPT controllers are available in sizes up to 80 amps, so if you have a larger system (like 1000W or more), an MPPT controller will be a better investment.
Is MPPT Worth the Extra Cost?
If you have a smaller solar setup, such as a single 100W panel, a PWM controller is likely sufficient, and the money you’d spend on an MPPT controller could be better spent on adding another panel or upgrading your battery.
However, for larger systems, the extra efficiency of an MPPT controller can make a significant difference, especially if you’re trying to maximize the amps you can generate. The efficiency gain of 10-20% might translate to a substantial increase in power over the course of a day, which can be very valuable for larger systems.
3 or 4-Stage Charging
Many solar charge controllers also feature 3 or 4-stage charging, a system that helps to charge your batteries in a way that maximizes lifespan and prevents damage. These stages are:
- Bulk: This is the initial stage when your battery is less than 80% charged. The controller delivers as much amperage as possible to the battery to charge it quickly.
- Absorb: Once the battery reaches about 80%, the controller maintains a set voltage and reduces the amperage to prevent overcharging, allowing the battery to safely reach 100%.
- Float: Once the battery is fully charged, the controller reduces the voltage even further to maintain the battery at a safe, low charge, preventing overcharging during periods of full charge.
- Equalization (Optional): This stage is a controlled overcharge meant to balance all cells within the battery, ensuring they charge equally. It’s particularly important for lead-acid batteries.
For systems with 4-stage charging, it’s crucial to set the correct parameters based on your battery type to ensure it charges safely and efficiently. Always consult the manuals for both your charge controller and battery to set the right values.
Does a Charge Controller Charge My Batteries Any Different from the Built-In Converter Charger in My RV?
Yes, a charge controller charges your batteries differently from the built-in converter charger in your RV. The converter in most RVs is usually a “dumb” charger that only uses the bulk charging stage. This means it provides a quick charge, but it doesn’t fully charge your batteries to 100%, nor does it include the other charging stages that help maintain the battery’s health over time.
A bulk-only charger often stops charging once the battery reaches a certain voltage but doesn’t taper off to ensure the battery is topped off safely, which can lead to undercharging and reduce the battery’s lifespan.
By contrast, a solar charge controller, especially one with multi-stage charging (like PWM or MPPT controllers), offers a more sophisticated charging process:
- The bulk stage quickly charges the battery until it reaches 80% capacity.
- The absorption stage then slows the charge to prevent overcharging, keeping the battery at a constant voltage while it charges to 100%.
- The float stage maintains the battery at full charge with a lower, steady voltage, which is essential for long-term maintenance.
If your RV’s converter only has one charging stage, it might be worth upgrading to a newer smart converter charger with 3 or 4-stage charging. Many modern inverters come with built-in smart chargers that offer multiple stages, improving the efficiency of your battery charging and prolonging the life of your expensive batteries.
So, while the RV’s built-in converter is a simple, cost-effective option, a charge controller (or an upgraded converter with multi-stage charging) ensures your batteries are charged more effectively and last longer.
How Do I Connect a Solar Panel to My RV Battery?
To connect a solar panel to your RV battery, you’ll need to use a solar charge controller as the intermediary. The solar panel will be connected to the charge controller, and the charge controller will then be connected to the battery. The charge controller is essential because it regulates the voltage going into the battery, protecting it from overcharging and preventing damage.
There are different ways to connect the charge controller to the battery, depending on whether you want a permanent or temporary setup.
- Permanent Connection: The most reliable and secure way to connect the charge controller to your battery is by using ring terminals. These are standard connectors that fasten tightly around the battery terminals with bolts. This method is ideal if your solar panels are mounted on the RV roof and you don’t need to disconnect the cables frequently.
- Temporary Connection: For portable solar panels, alligator clips (like those found on jumper cables) are a convenient option. These clips are easy to attach and detach, making them ideal if you need to set up and take down your system regularly.
When connecting the cables, always remember that RED is positive (+) and BLACK is negative (-). This is crucial to avoid short circuits or damaging your battery.
In summary, whether you choose ring terminals for a permanent installation or alligator clips for portability, the key is to connect your solar panel to a charge controller, which then connects to your battery, ensuring a safe and efficient charging process.
See Also: How To Install Solar Panel On RV Roof & Connect To Battery
How Do I Know How Charged My RV Battery Is?
Unfortunately, most RV manufacturers don’t make it easy to accurately monitor your battery’s state of charge. While some newer, high-end trailers are improving in this area, most RVs come with basic monitoring screens that show rough percentages—like 0%, 25%, 50%, and 100%. While convenient, these readings are often inaccurate and don’t provide the detailed info you really need.
Some solar charge controllers do have built-in screens that display the battery voltage, and while these can be helpful, they’re still not entirely reliable for determining your exact state of charge. The voltage can fluctuate and doesn’t always correlate directly with the battery’s true charge level.
The most accurate way to monitor your battery’s charge is with a battery monitoring system. These systems use a shunt that is hardwired to your battery, providing real-time data on the battery’s state of charge.
A popular choice is the Victron BMV-700 Battery Monitor, which gives you detailed readings on your battery’s percentage, voltage, and current consumption. Once you set the total amp-hours of your battery bank, it provides an accurate percentage of how charged your battery is at any time.
If you don’t have a battery monitor and are relying on voltage readings, you can use some general guidelines to estimate your state of charge. For example, here’s what the voltage typically shows for a 12V AGM or wet cell battery:
Remember, these are just general guidelines, and your specific battery type might have slightly different values. Always refer to your battery manual or consult with the manufacturer for more accurate readings.
By investing in a battery monitor, you’ll get a clearer and more reliable understanding of your battery’s charge level, ensuring you never run into unexpected power issues while on the road.
How Low Can I Safely Discharge My RV Battery?
The safe depth of discharge (DoD) and usable amp-hours of your RV battery depend on the battery type.
For most RVs and trailers, the factory-installed flooded lead-acid batteries should never be discharged below 50% of their total capacity. Going below 50% repeatedly can significantly shorten their lifespan, so it’s best to recharge them before they dip too low.
Lithium batteries are much more resilient and can be discharged down to 20% without risking damage. Lithium batteries offer a deeper usable capacity, which is one reason they’re becoming increasingly popular for RV use.
Now, you might wonder: What if I discharge my lithium battery to 10%?
While it’s not ideal, doing so occasionally won’t immediately destroy the battery. However, consistently discharging it to such low levels will reduce its lifespan. For the best results, it’s a good practice to keep lithium batteries above 20% to ensure they last as long as possible.
As always, these are general guidelines, and it’s important to refer to your specific battery’s manual or consult the manufacturer for the exact safe discharge voltage and percentage. Following these recommendations will help maximize your battery’s performance and lifespan.
What is the best 12V battery for RVs?
I recommend watching this video (less than 10 minutes) about the different lead-acid battery types often used in RVs and what each of them does good and bad.
What is not talked about in the video is lithium batteries which are becoming more and more popular, although at a much higher cost than flooded, AGM, and cell.
If you plan on living full-time in your RV it can definitely be worth the investment. I recommend purchasing 12V lithium batteries from reputable companies like Battle Born or Renogy.
Click here to see Battle Borns 100AH 12V Lithium on Amazon or Click here to see Renogy 100AH 12V Lithium on Amazon.
Both of these are “drop-and-replacement” which means that they’re extremely easy to install on RVs.
You should, however, make sure that the converter charger in your RV supports lithium batteries.
See Also: Best Deep Cycle RV Battery (AGM, SLA, 12V, 6V)
Parallel vs Series: Which Should You Choose?
When setting up your solar panels or batteries, you can wire them in either series or parallel, and each configuration affects the output differently. It’s essential to understand these differences to ensure your system works efficiently and safely.
Series Connection:
In a series connection, the positive wire from one panel is connected to the negative wire of the next panel, and this pattern continues. The main result of wiring in series is that the voltage adds up, while the amperage stays the same.
For example, if you have two 12V panels each producing 18V and 5 amps, when wired in series, you will get 36V (18V + 18V) at 5 amps.
This configuration is useful when you need to increase the voltage to match the input requirement of your charge controller, especially if you’re using a 12V battery and need a higher voltage to efficiently charge it.
Parallel Connection:
In a parallel connection, the positive wires from each panel are connected together, and the same is done for the negative wires. In this case, the voltage stays the same, but the amperage adds up.
Using the same example, if you have two 12V panels, each producing 18V and 5 amps, when wired in parallel, they will still output 18V (the same as each individual panel) but now with 10 amps (5A + 5A).
Parallel wiring is useful when you want to increase the total amperage available to charge your battery but don’t need to increase the voltage.
Which Configuration Should You Use?
The choice between series and parallel depends primarily on your solar charge controller and what it can handle.
- If your controller can only manage a certain voltage or amperage (for example, some controllers can’t handle more than 10A or 120W input), you’ll need to pick the configuration that keeps the current and voltage within those limits.
- Series is better for increasing voltage without increasing current, making it ideal for controllers designed to handle higher voltage inputs.
- Parallel is better for increasing current and is often used when you want to generate more amperage but keep the voltage the same.
Before you set up your system, check the specifications of your charge controller to ensure that it’s rated to handle the voltage and amperage you’ll be generating with your panel configuration. Using wires that are thick enough to handle the increased amperage and voltage is also important for safety and efficiency.
What is the Difference Between Solar Panel Types (Poly vs. Mono)?
When choosing solar panels, you’ll typically come across two main types: monocrystalline and polycrystalline. Each has its pros and cons, and understanding the differences can help you make the right choice for your needs.
Monocrystalline Panels
Monocrystalline panels are made from a single crystal structure, which gives them a higher efficiency rate. Typically, they have an efficiency range of 15-24%, meaning they can convert more sunlight into electricity than polycrystalline panels. This higher efficiency also makes them more space-efficient, meaning you need less area to generate the same amount of power.
However, because of the manufacturing process, monocrystalline panels are more expensive than their polycrystalline counterparts. Despite the higher cost, their efficiency and long-term reliability often make them a better investment for those who want optimal performance.
Polycrystalline Panels
Polycrystalline panels are made from multiple crystal structures and are typically cheaper to produce. As a result, polycrystalline panels are usually more affordable for the consumer. However, they tend to have a lower efficiency rate—usually around 12-17%—meaning you may need more space to generate the same amount of power as monocrystalline panels.
One downside to polycrystalline panels is that they don’t handle heat as well as monocrystalline panels. In high temperatures, their performance can drop slightly, which might be a consideration depending on where you live.
Which Should You Choose?
If you’re looking for higher efficiency, more space-saving power, and don’t mind paying a little more, monocrystalline panels are the better choice. They perform well in various conditions, including cooler temperatures, and are typically more reliable in the long term.
If you’re on a budget and have plenty of space for your panels, polycrystalline panels can still be a great option. While they’re less efficient, their lower cost makes them an attractive choice for many users.
Ultimately, it depends on your priorities—whether it’s performance and efficiency or cost savings. For overall efficiency and reliability, I recommend monocrystalline panels.
Can I Use the Electrical Outlets in My RV if I Have Solar Panels?
The short answer is yes, but with a caveat. Solar panels on their own cannot directly power the outlets in your RV because they generate 12V DC power, while your RV outlets require 120V AC power.
To use the energy your solar panels generate for powering your RV outlets, you’ll need an inverter. An inverter converts the DC (direct current) power stored in your batteries into AC (alternating current) power, which is what your RV’s outlets require.
Once the solar energy is stored in your battery and converted to AC by the inverter, you can power your 120V outlets as usual.
For example, a 12V to 120V inverter works great with RV batteries and can be connected to your AC panel to provide power to your outlets.
So while solar panels alone can’t power your RV outlets, with an inverter, you can certainly use the solar energy stored in your batteries to run your household electronics while off-grid.
I have done my best to explain solar power and how it works with the products surrounding them. Please let me know if you have a question, or if there is something you feel should be corrected or added.
It would be great if we could create a discussion in the comment area and help each other out. Making solar easy to understand isn’t easy, but together we can make it work.
Hi, was wondering if any/all of your solar panel recommendations would work to just keep our 12v battery in our 5th wheel charged while being stored. And, if it’s ok to leave it hooked up and left alone for weeks st a time.
Hello Lori,
While all of the panels in this post would work for that, it would be overkill to use one of them only to trickle charge your batteries. If you don’t plan on using the solar panel when you’re out camping as well, I would recommend something smaller like this 8W trickle charging kit (https://amzn.to/2F1RBYm) that will keep your batteries charged up while your 5th wheel is in storage. These kind of trickle chargers are safe to leave hooked up to your battery unattended.
Hi Jesse,
This is one of the best overviews of solar PV for RV owners. One that I’ll recommend.
I’m a bit surprised, though, about your statement, “I recommend polycrystalline panels,” after your foregoing discussion seems to attribute the cited advantages to the monocrystalline panels.
I’d like to suggest to add, as a rule of thumb, about 2 hours to your charge time calculations to allow for the tapered charging that is necessary to reach close to 100% capacity (although some of that may be accommodated in the fringe hours later in the day when panel output is dwindling). Users who might rely on your examples to calculate panel sizes and never verify the outcome, or who, lacking precise monitoring instruments, just count recharge hours, could be unaware that regularly using 50 % of capacity may cumulatively result in significant undercharging and even battery damage.
Also one should account for some 2% to 12% cycle overhead/inefficiency between charging input and usable output.
I think it is good to keep the explanations and examples as easily understandable as you have stated them. However, an additional paragraph could mention (a) that at higher temperatures (summer heat waves plus inside vehicle) batteries get so hot that their self-discharge is substantially increased. And (b) that at low temperatures capacity is reduced such that one needs to figure about 60% more (AGM) capacity to sustain the same demand around freezing temperatures, about twice as much around -10 and about four times as much around -40 degrees.
Cheers!
Wolf Naegeli, PhD, co-founder (1974) Swiss Society for Solar Energy
Hello Wolf,
First, I would like to thank you for stopping by, reading, and commenting. I really appreciate you taking the time to help me improve the post and clear some things up.
The sentence about polycrystalline panels was an error that went through somehow, thanks for pointing that out!
I’m going to learn more about the suggestions you made to understand them fully and update the post.
Again, thank you very much!
Hi folks,
I am a newbie suv mostly boondocking camper. I am a bit overwhelmed by solar power, but your information makes more sense of it all than other sources. Even with that said, I cannot decide on what i need so i am asking for your help. My main priorities are to run a portable cooler (like: cho Power Sports Portable Freezer Cooler AC/DC Compressor Refrigerator Fridge Trolley Wheels for Truck RV Boat Party Picnic Camping (40 Liter) – Amazon, rechargeable fan (Geek Aire Rechargeable Outdoor High Velocity Floor Fan,10” Portable 7800mAh Battery Operated Fan with Metal Blade,360°Vertical Tilt, 24 h Run Time Cordless Fan for Camping – Amazon), cell phone and laptop.
Hello Cindi, thanks for your comment.
So the solar panel will generate 12V electricity when it’s sunny, but that power has to be stored somewhere for it to be practical. Is the plan to use the batteries in your vehicle?
Based on your needs, I recommend getting a portable power station. The Jackery Explorer 500 (click to view on Amazon) would be one option, but the larger Jackery Explorer 1000 is what I would get to make sure your fridge will keep running even if it’s cloudy for a couple of days.
When you have a power station you can start looking for solar panels to recharge it with. For permanent installs on top of your vehicle, the Renogy 100W solar panels are great. If you’d rather have a portable panel that you take out when needed, the Renogy 100W suitcase is a good one. Both of them would connect to the Jackery via an MC4 to 8mm adapter. To extend the cables, I use Windynation MC4 extension cables.
There are more ways to go about it as well that would be cheaper but more complicated and not as neat, like buying a deep cycle 12V battery, an inverter, a solar panel, and a charge controller.
I get that it can be overwhelming, so let me know if you have any questions about any of this.
Jesse
Thank you for the incredible resources you provide on our site – I am so happy to have discovered The Camping Nerd! We recently purchased an older 23′ RV to enjoy boondocking. We’ve never used solar before but would like to start. The two existing 6v Trojan T-105 batteries need to be replaced and we want to have a relatively simple setup for solar charging for the RV. We’re a bit confused as to whether we should be purchasing replacement batteries that are specifically designed for solar charging, or whether we can use a new pair of standard 6v deep cycle RV batteries to connect to one of the solar panels and charging stations you recommend. Thanks for your advice,
Christy & Greg
Thanks for the kind words!
The Trojan 6v batteries are great, are they damaged or do you plan to make a battery bank larger than 225Ah?
You can definitely replace them with 6V batteries, but if it was me I would replace them with 12V AGM batteries. The main reason for this is that if one battery stops working you won’t be without 12V power. If you do buy 6V batteries, just make sure it’s a battery type supported by the charge controller that comes with the solar panel.
Jenni has written this article regarding the best RV batteries. Let me know if you have any questions.
We appreciate your help – we need to replace the Trojan 6v batteries as they appear to be damaged, not because we need a larger battery bank. We’ll see if there’s a way to fit a 12V AGM and snap-top battery box you recommend in front of our trailer. In order to go solar, it sounds like we need a working battery system (two 6V or a single 12V AGM) and a solar panel like the Renology 100W suitcase solar panel (should we get a 10A or 20A controller w it?) Do we also need a portable power station like the Ecoflow, or does the solar panel connect to the main batteries? Thanks!
With a 100W panel, a 10A charge controller is enough since one 12V 100W panel outputs around 6A.
A portable panel like the Renogy 100W will connect to the batteries via a charge controller and charge your 12V batteries. It will not provide electricity to the outlets in your RV, since the 12V (or 2x6V) batteries only power 12V devices in your RV like the water pump, lights, kitchen/bathroom fan, etc. A power station like the ones from Ecoflow is basically a battery bank with a charge controller and an inverter built-in. The inverter turns the 12V battery power into 120V AC power so you can power household devices and appliances. So if the plan is to just have a solar panel to keep your RV batteries charged you don’t need anything but a solar panel and a charge controller.
That’s great news! We’ll order the battery and portable panel through your links. One more question – we have a small slide-out – will that work off the 12V or should we plan on hand cranking only?
Awesome! Yes, slide outs run on 12V DC power so there is no need to manually extend or retract it as long as your batteries are charged.
Bless and thank both of you for the solar article and service, I will be a new RV class c camper October 10, 2021. I have ordered a 2022 Conquest 6237D. What are your feelings about the Zamp products? I was thinking I would need a 300 – 500 amp system. My older brother has convinced me that with the limited mobility I need to use a portable system as there is no way I’ll be able to climb up on the roof to clean solar panels daily.
My background: I will be camping out in the AZ desert near Rich Hill AZ, North of Phoenix. I will be 70 years old in July, bad knees, weigh 440lbs, very hard to move around, living by myself trying to live a dream of prospecting/metal detecting! My Wife may or may not be coming out. I will leave Central Ohio as soon as RV checks out and not come back till May 2022.
There will not be any public utilities for 95% of the time I camp, so to maximize day count before needing to dump and refill water tanks, gasoline, and propane, I need to maximize my solar usage instead of gasolene and propane!
Can you both give me your thoughts and recommendations!
Hi Randall,
Awesome, I’m excited for you! I have some questions.
Do you know whether your Class C has a solar prep plug or not? It’s usually either a Furrion or a Zamp solar prep port and it’s basically a quick connection to your RV batteries.
If you would rather connect panels directly to your RV batteries there are lots of options, but how big of a panel you need depends on how many amps you’re going to use daily.
What do you plan on using in the RV that runs on 12V DC power?
Thanks for this article… it’s a really terrific run down of options. Well written, and clear for us novices.
I am leaning toward the Renogy 200 watt kit to plug into the side of my travel trailer (it’s a Go Power solar on the side plug)
I’m considering this panel: https://ca.renogy.com/200-watt-12-volt-monocrystalline-solar-suitcase-with-voyager/ but the Renogy website is not clear… it comes with clips for the batter, but do I need to buy an adapter for the SAE plug? Are the battery connectors removable? Unfortunately, Renogy does not seem to answer emails…
Would really appreciate your insight if you know the answer.
Hi Rob,
First I’d like to make sure that the GoPower plug can handle the amperage (11.7A) from the 200W panel. There might be a sticker by the port or a manual that tells you the max amperage.
The way those Renogy panels are wired is like this: Solar panel -> charge controller -> MC4 cables -> optional Battery clamps cable. So you don’t have to use the battery clamps cables, and can use an MC4 to SAE adapter instead. If it has a 20A max you’re good to go, but if it has a 10A max you’ll have to stick to a 100W panel.
The male MC4 connector from the charge controller is a positive wire (check the wiring on the panel to be sure) and the female is negative, so you should look for an adapter with a positive female, like this MC4 to SAE (click to view on Amazon CA).
It’s also important to know how the SAE plug on your camper is wired since not all manufacturers wire them the same way. If you have a multimeter you can check the polarity of the solar plug and make sure that the adapter I linked to is compatible.
If the solar plug has a positive female, just like the adapter above, you could get this adapter instead even though the colors are wrong, or you can simply get an SAE reverse polarity adapter. As long as the positive wire coming out of the charge controller is ending up in the positive end of the solar plug you’re good.
To extend the wiring between the solar panel and the MC4 to SAE adapter, use MC4 extension cables.
Sorry if my answer is confusing, let me know if I can make something more clear.
This is fantastic advice, thank you. I went ahead and ordered what I thought were the necessary adapters and will attempt to wire everything up this week. The adapters also included a secondary adapter to reverse the polarity, in case I need it. I’m sure I’ll be checking back to your explanation once or twice more. Thanks again!
Jenny, can you tell the difference in these, both with the less efficient PWM controllers – is the difference the ‘waterproofing and kickstand’? Price difference is substantial:
Renogy 200 Watt Monocrystalline Foldable Solar Suitcase, 200W Panel-20A Controller – $340
Max Power at STC: 200W
Short Circuit Current: 11.7A
Open Circuit Voltage: 21.8V
Opitmum Operating Current: 10.5A
Optimum Operating Voltage: 18.5V
Operating Temperature: -4℉ ~ 140℉ / -20℃ ~ 60℃
Dimension: 35.6 x 25.9 x 3.1 in
Weight: 35.9 lbs
Renogy 200 Watt Off Grid Portable Foldable Solar Panel Suitcase Built-in Kickstand with Waterproof 20A Charger Controller, 200W-Waterproof – $594
Maximum System Voltage: 600VDC(UL)
Open-Circuit Voltage: 21.2 V
Optimium Operating Voltage: 17.7V
Short-Circuit Current: 11.72A
Optimium Operating Current: 10.35A
Folded Dimension: 41.3 x 21.1 x 3.1 inches
Weight: 33.60 lbs
They both use water resistant charge controllers and have a stand. The difference is that the Renogy Eclipse panels are supposedly more efficient panels. Not worth the much higher cost, in my opinion.
Oh gosh, I think the difference is that the less expensive one isn’t using the ‘eclipse’ solar panels. Both use the same 20amp PWM waterproof controller as far as I can tell.
Jesse, I know I’m probably making you nuts, but I keep coming back to your post. So in the FAQs you talk about doing the conversion from watts to amps (watts/12=amps) to make things easier, but in my newbie mind I’m thinking this only applies if you have an inverter from your house battery(s) to the AC plugs in RV.
If I’m understanding it right, you guys use a ‘Solar Generator’ that has built in inverter and plug it into your RV to use your AC plugs. Do you also have an inverter setup from house battery(s) to AC plugs in RV?
If not, since most if not all the ‘solar generators’ are based in watts how do you calculate this? Does my question even make sense? An example, the 800w kcup coffee pot you mention in another post. If it was used 15 min/day, how would I determine battery draw based on the watts? In amps that would equate to 16.67 amps/day (800/12= 66.27 x .25 (15min/day) = 16.67amps/day for coffee pot.
Well crud, I could just take the watts of ‘solar generator’ and divide by 12 for it’s total amps and then keep everything in amps. Could it be this simple?
I’m happy to help in any way I can, even though I’m not an expert in any way.
We only use solar generators and do not have an external inverter setup.
With solar generators, it’s easiest to just look at the rated watt-hours when comparing them, since the amps and volts differ depending on the manufacturer and batteries used. For example, my Goal Zero Yeti 1000 is rated at 96.8Ah @ 10.8V, while my Explorer 1000 is rated at 46.4Ah @ 21.6V.
That said, there is nothing stopping us from dividing the rated watt-hours by 12 to get an idea of the capacity, especially if you’re comparing it to other 12V batteries or know how many amp-hours you use daily.
With campers that use 12V batteries, it’s easier in my opinion to think in amp-hours since it’s relatively easy to figure out the battery capacity. It would be easy to find the watt-hours too since all it takes is the amp-hours * volts.
Our house battery is rated as a 75Ah 12V battery, which means that it should have about 900 watt-hours. It’s a little more complicated than that though since it depends on discharge rates among other things.
Your example is correct, but if you’re using an inverter I suggest multiplying the 16.67 by 1.105 to take the inverter efficiency into account. So using the 800W coffee maker for 15 min would use about 18.4 amps DC.
The inverter efficiency should be considered when calculating what a solar generator can do and for how long as well, and most companies advertise an 85% efficiency.
Let me know if you have any questions or if I misunderstood any parts of your questions. If somebody spots something inaccurate in my answer I’d appreciate a correction.
Thanks Jesse and sorry for late reply – work life, ugh… Anyway, at this point convinced to buy/build a portable solar generator. Just not sure what we are going to do with our little trailer at this point, so don’t want to spend the money to have someone install an inverter on it. Appreciate your help, I’ve learned a lot!
I have a portable solar panel connected to the batter of my travel trailer. Suddenly the ceiling lights, water pump, awning and slide were not working. I disconnect the solar panel from my battery and now everything works. Do you know why this is happening?
Hi Tina,
What panel do you have and how have you connected it to the battery?
It’s a DOKIO . Connected the clamps directly to the battery.
Ok, sounds like there might be a short. Does the charge controller seem to be working correctly when hooked up to the batteries? As in is it showing the battery voltage, amps produced etc?
All is shows is 9.9 v. I push the little buttons on there and nothing changes. when it’s not connected is reads 12 v
Can you try to connect only the solar charge controller to your battery (if possible) and tell me what the charge controller tells you.
We tested the panel and it is reading correctly.
Not sure what you mean by connecting only the charge controller to the battery. Do you mean by pass the solar panels?
Yes, the screen on the charge controller should tell you some information if you connect only the charge controller to the battery but not the solar panel.
The model is FSP-100M(50W*2)
Hi Jesse I agree with all the above, a great, well written information website. I am looking at solar portable panels for my Aliner Ranger camper trailer. Your site answered many of my concerns however in trying to better understand my electrical system I have two questions that if you could answer would help me going forward. (1)When my Aliner is connected to shore power is it the battery that is being charged and then an inverter changing the DC to AC for use of the AC outlet or is there two separate systems, one charging the 12v battery for DC power and another suppling AC power to the AC outlet ? (2) I want to hook the solar panels with the built in charge controller directly to the battery with alligator clips do I have to disconnect the battery cables that are on of the trailer first or is leaving them on while using the solar panels not a problem? Thank you for any assistance you can provide.
Hi,
1. Your camper has a converter charger that turns AC into DC. Both to charge the camper battery, and to provide power to the 12V system. So technically you don’t need the 12V battery when plugged into shore power.
Shore power reaches the RV distribution panel first. The distribution panel then supplies AC power to the 120V outlets in your camper, and supplies AC power to the converter charger that will power the 12V system and charge the 12V battery.
The 12V battery does not power anything until you’re disconnected from shore power, and when it does it goes through the DC fuses you can see on the same distribution panel.
2. You can leave the charge controller connected to the the 12V battery. It doesn’t matter if you’re plugged in to shore power or not. When you plug it in, the converter charger will just help charge up the 12V battery.
Hope I didn’t make it confusing, please let me know if you have any other questions.
Jesse,
I enjoyed reading your article. It confirmed alot of what I’ve been dealing with. (I installed a 10KW array at my home in GA). I now am retired, have sold that house and travel this country in a Class A RV. I was looking at the Charger/regulator you recommended in your article and want to inform you that Amazon states the following:
“Currently unavailable.
We don’t know when or if this item will be back in stock.”
Do you have an upgrade recomendation?
Joseph
Hi,
Sounds like you’re living the life!
Thanks for letting me know, I have updated the article and replaced it with a different solar charge controller. I have also added instructions on how to connect it to the panel and battery, let me know if you have any questions.
Hi Jesse,
Thank you for this article and other very helpful articles on your site. I especially liked the article on RV fridge issues in propane mode – very well written.
We purchased a Merlin Solar BXD95 panel. As the name implies, it’s a 95 W panel. The weight is only about 8 pounds which we appreciate. They claim the panel is “mil-grade”. So far, it has worked very well. The cost was a bit high though ($380). We use the Merlin Solar MST-TS15 MPPT controller in our setup. Charge power for 12V is 195 W. I believe the controller cost was $100. To connect to our RV battery we use a cool adapter we found online that connects to our trailer’s 7 pin plug. Go Power model GP-PSK-7PIN. I could have made this cable myself but didn’t bother. I also purchased an 8 AWG extension cable for our setup.
So far, it seems our lead acid battery is fully charged in about one hour or so. We switched all of our lights to LED types. We also take quick showers so the water pump and hot water heater are not on much. We don’t have a TV in our camper and we don’t play the stereo much either. We do charge both of our phones. But we were just camping last week here in Maryland and used the furnace a bit. I am curious if you have looked at Merlin Solar or have any comments on our solar setup? Thanks again for your excellent site!
Hi,
Thanks for your comment and sharing your setup, sounds like you’ve figured out what you need and chosen high quality parts.
I haven’t heard about Merlin solar before and I agree that the cost for your 95W panel was quite high. I hope they offer excellent warranty and support for that price, in addition to a great product.
Hi Jesse,
We have an Airstream RV and learned that they install Merlin Solar panels on their newer model campers. That’s how we learned of Merlin. I also learned Merlin supplies solar panels to the US military so they must be very rugged. I believe they are also “walkable”. They also design and build their products in the US. These were all very important factors to us. I am sure the price is higher since they are US built.
We have used our solar panel for 2 years now with no troubles. I am not exactly sure what the warranty is. I will have to look that up. I know their residential solar panels have a warranty like all the other brands.
Thanks,
Eric