Trailers & 5th Wheels
Travel trailer and 5th Wheel power systems are unique in several ways:
Plenty of roof space capable of accommodating a large solar array.
Limited alternator charging because of the 7-pin connection to the tow vehicle.
Heavy loads like air conditioners and residential refrigerators requiring large battery systems and inverter/chargers.
Spacious bays allow for a wide variety of battery options.
The step-by-step guide below takes you through the myriad of options and design considerations for developing a custom RV solar panel power system.
Educational Videos for Trailers & 5th Wheels
Join Garret and Cody as they discuss system upgrades and the solar installation process for an ATC 4528 Toy Hauler. This fifth wheel installation includes upgrades to their battery system, battery bank, power system, and monitoring system. Learn more about wire routing and component placement strategies and challenges throughout the video.
Custom Configuration
1. Select an RV battery bank: The RV battery bank is the heart of the system. We recommend LifeBlue lithium batteries for your travel trailer solar panel system because of their built-in Bluetooth monitoring, high quality, and ability to expand over time.
We sell LifeBlue batteries as a base kit, which includes one battery, a Victron BMV-712 battery monitor, cable, lugs, and heat shrink, plus expansion kits, which include one battery and parallel cables. For two batteries, select one base kit and one expansion kit. If you want three batteries, get one base kit and two expansion kits.
If your plan is to run an air conditioner, you will get about 1 hour of runtime on a 15,000BTU A/C running at full, per every 200Ah of lithium battery capacity. You will also need at least a 3000VA Inverter and an Easy Start Kit.
Do not let your lithium batteries get below -10° F. Lithium batteries will not charge below 32° F.
Estimated Installation Labor
300Ah LifeBlue Lithium System with BMV-712
11 hours / $1,595 (additional)
This is a complete LifeBlue lithium RV battery base kit with a Victron BMV-712 Bluetooth battery monitor. The monitor is included to provide cumulative battery bank data, compatible with Victron VRM monitoring. When expanding the battery bank, do not mix battery models and limit the battery bank to four batteries.
This kit is designed to be an add-on to an existing LifeBlue battery system.
For larger systems, Victron lithium batteries are recommended because of their extremely compact footprint. Or, if you only need one battery, a monitor is not required for single LifeBlue battery.
2. Establish Tow Vehicle Compatibility: A 7-pin tow vehicle connection won’t allow for high current alternator charging, but you can get about 18A when you use a Victron Orion DC/DC charger on the trailer side of the connector. Another advantage of this kit is that it will prevent unwanted current flow from the trailer to the tow vehicle’s starter battery. This kit is not necessary with Flooded or AGM batteries.
With most tow vehicles and trailers, the 7-pin connector allows alternator charging of the trailer’s battery bank. The trailer's seven-pin connector is typically hardwired leaving the tow vehicle responsible for charging the two battery systems. Unfortunately, many vehicles don't have any protection built-in, which leaves both battery banks tied together when the trailer is plugged in. This is a major concern for lithium house batteries as their resting voltage is much higher than a typical tow vehicle engine battery. This causes the lithium battery to slowly discharge into the tow vehicle battery and because lead-acid batteries can dissipate energy in the form of heat, this will continue to happen until the lithium battery is below 20%, which could potentially cause damage to the lithium battery. This isn't good for the system and can be avoided by installing this kit or simply unplugging the trailer when left for more than a week.
This article on high current alternator charging may be interesting:
High Current Alternator Charging and the 7-Pin Connector
Estimated Installation Labor
Tow Vehicle Compatibility
1.5 hours / $218
Enable DC/DC charging from your alternator to a secondary Lithium, AGM, or Flooded battery bank. This kit is ideal for systems with older alternators or lithium batteries with input current limits under 100A.
Ideal for: Trailers/5th Wheels/Truck Campers
*Please note that cables length needs may vary by application. Please email info@amsolar.com if you would like to customize the cable lengths to better suit your needs.
3. Select solar charging system: Trailer and 5th Wheels tend to have a lot of roof space which allows for a wide variety of solar array configurations. One of our favorite systems is 4x 200W solar panels on an 85A solar charge controller. This gives you room to add more panels in the future if you find you need more energy. If you have a solar pre-wire, check out section 3a of the Airstream page.
For a complete explanation of everything you would want to know about how to design a solar charging system, check out our Solar Charger Design Guide.
The Victron SmartSolar MPPT charge controllers are compatible with any battery type, can work on 12V or 24V battery systems, and communicate status via Bluetooth.
We recommend a minimum of 500W for any system with a residential refrigerator.
If you want to use a portable panel, we recommend oversizing the central charge controller so it can handle both the roof array and the portable panel.
The Victron SmartSolar MPPT charge controllers are compatible with any battery type, can work on 12V battery or 24V battery systems, and communicate status via Bluetooth.
Estimated Installation Labor
4x 170W on 85A Controller
15 hours / $2,175
Communicates battery voltage and solar charge rate to a smartphone or tablet via Bluetooth, Expandable up to 700W, Advanced MPPT charge controller delivers approximately 20% more energy than PWM, Combiner box covers roof penetration and allows for easy upgrades, Panel(s) can be tilted
Communicates battery voltage and solar charge rate to a smartphone or tablet via Bluetooth, Expandable up to 1200W, Advanced MPPT charge controller delivers approximately 20% more energy than PWM, Combiner box covers roof penetration and allows for easy upgrades, Panel(s) can be tilted
Communicates battery voltage and solar charge rate to a smartphone or tablet via Bluetooth, Expandable up to 1400W, Advanced MPPT charge controller delivers approximately 20% more energy than PWM, Combiner box covers roof penetration and allows for easy upgrades, Panel(s) can be tilted
Add panel kits ending in Cable to connect to the AM Solar combiner box.
Add a side port and portable panels.
4. Select an Inverter/Charger System: The Victron Multiplus or Quattro inverter/chargers combine an inverter and a charger in one unit. They also offer PowerAssist, which means that they can combine shore power with battery power when necessary. Our kits come with everything you need to upgrade your trailer or 5th wheel.
For a Trailer or 5th Wheel, you will want kit variants that include the phrase “RV Upgrade Kit”. If your Trailer or 5th Wheel has a 50A AC panel, you will want the Multiplus-II inverter/charger.
In order to fully support the 3000VA inverter, you will need a battery bank that can handle 300A of current outflow or three LifeBlue batteries. A 3000VA will work on a smaller battery bank, but will only work like a 2000VA inverter if only two batteries are used.
If you plan on running an air conditioner, you will need the 3000VA inverter system with an Easy Start kit.
If you plan on running an air conditioner, you will need the 3000VA inverter system with an Easy Start kit. If you plan on running two air conditioners, consider a 24V system with a Victron Quattro 5000.
Estimated Installation Labor
Multiplus Inverter (RV Upgrade Kit)
17 hours / $2,465
The MultiPlus is a powerful true sine wave inverter, a sophisticated battery charger that features adaptive charge technology and a high-speed AC transfer switch in a single compact enclosure. Rated at 3000VA.
Note: Some Keurig coffee makers are known to be incompatible with inverters. In some cases, this will just result in a loud buzzing noise while operating, and in other cases, it will result in inverter overload and failure to operate. This doesn't mean your inverter will be damaged or that trying to use your coffee maker is dangerous; however, AM Solar cannot support compatibility issues resulting from a Keurig coffee maker. We recommend doing some research and purchasing a different coffee maker if you find yours to be incompatible with your inverter system.
If you have a 50A coach, we recommend looking into our MultiPlus-II 12/3000/2x 120V VE.Bus Inverter/Charger kits for 50A coaches.
Please note there is currently a nation-wide shortage of Duplex AC breakers (primarily 15/20). Our kits are designed to include these, but we may need to make substitutions due to stock level. Please email info@amsolar.com if you have any questions about this.
Steady State: 2400W
Surge: 6000W
Voltage Output: 120V AC
Voltage Input: 9.5-17V
No Load Draw: 8-20W
Waveform: Pure Sine
Frequency: 60hz
Charger: 120A
Passthrough: 50A
Efficiency: 93%
Dimensions: H 14.3" x W 10.2" x D 8.6"
Extra: PowerAssist
For use with 50A coaches, the MultiPlus-II is a powerful true sine wave inverter, a sophisticated battery charger that features adaptive charge technology, and a high-speed AC transfer switch in a single compact enclosure. Rated at 3000VA.
Note: Some Keurig coffee makers are known to be incompatible with inverters. In some cases, this will just result in a loud buzzing noise while operating, and in other cases, it will result in inverter overload and failure to operate. This doesn't mean your inverter will be damaged or that trying to use your coffee maker is dangerous; however, AM Solar cannot support compatibility issues resulting from a Keurig coffee maker. We recommend doing some research and purchasing a different coffee maker if you find yours to be incompatible with your inverter system.
Steady State: 2400W
Surge: 6000W
Voltage Output: 120V AC
Voltage Input: 9.5-17V
No Load Draw: 8-20W
Waveform: Pure Sine
Frequency: 60hz
Charger: 120A
Passthrough: 2x50A
Efficiency: 93%
Dimensions: H 22.7" x W 10.8" x D 5.4" (48lbs)
Extra: PowerAssist
Similar to the MultiPlus, the Quattro is also a combined inverter and charger. Additionally, it can accept two AC inputs and automatically connect to the active source. Its many features include a true sine wave inverter, adaptive charging, hybrid PowerAssist technology plus multiple system integration features such as three or split phase operation and parallel operation. Rated at 5000VA.
Please note there is currently a nation-wide shortage of Duplex AC breakers (primarily 15/20). Our kits are designed to include these, but we may need to make substitutions due to stock level. Please email info@amsolar.com if you have any questions about this.
Steady State: 4000W
Surge: 10000W
Voltage Output: 120V AC
Voltage Input: 19V-33V
No Load Draw: 10-30W
Waveform: Pure Sine
Frequency: 60hz
Charger: 120A
Passthrough: 2x 100A
Efficiency: 94%
Dimensions: (24V) H 17.5" x W 13.0" x D 9.6"
Extra: PowerAssist
For smaller Airstream trailers, the Multiplus 2000VA is popular choice, as well as a standalone 1200W inverter with a separate charger.
5. DC Distribution: This is only necessary if you are upgrading to a 24V battery bank.
When using a 24V battery bank it is important to step down the voltage from 24V to 12 Volt for DC loads.
Estimated Installation Labor
24V DC Distribution Kit
2 hours / $290
This kit includes everything you need to connect a 12V DC distribution block to a 24V battery system.
6. Optional components and tools: You may consider including these items in your purchase.
Tools - Make sure you have something equivalent to everything on the top row of this page.
Tech Support - Each kit comes with a set amount of free tech support, if you feel you may exceed that, you can purchase more here.
