The story of our System
We started out with just a few solar panels to keep our 4 lead-acid house batteries charged in the hope we also could use the power generated. We mainly stayed in RV parks in the beginning and only used our batteries when traveling.
The current system has 4400 Watt of large residential solar panels mounted on the trailer (2400 Watt) and RV (2000 Watt). We have upgraded the battery system to use Tesla Model S Lithium battery modules with a 24 Volt, 4000 Watt Inverter. We almost always boon-dock and even when staying in an RV park (dumping and washing cloth) are we not plugged in unless we need both Air Condition units or Air Condition during the night.
Charging in the summer ends very fast most days are the batteries charged before 11 AM even when we use a lot of power in the morning to heat with the Electric Fireplace. During the day we are trying to use as much power as possible. Heating water, using an electric cooking plate, baking with convection oven and run air condition when needed. We average 10-12 KWh energy from the sun used each day.
We got two 160 Watt solar panels installed by an RV place in Colorado Springs. We still had our original 2000 Watt ME2012 Modified Sine Inverter.
Replaced our 4 batteries that were 7 years old with new Flooded Deka 235 AH, our existing watering system moved right over.
Added 2 more panels for a total of 640 Watt and replaced the controller with a 45 ampere Morningstar Tristar MPPT45.
Upgraded inverter to Magnum MS2012 2000 Watt PureSine. Efficiency on running high loads increased over 20% from 200 amperes to 160 amperes when using the Microwave oven.
Added 3 Kyocera 260 Watt solar panels on the trailer. The trailer is used to transport our Jeep that does not flat tow since it is being run hard off-road. The power is transferred to the RV with a DC connection with Anderson Plugs to disconnect when driving.
A frame was built to raise the engine batteries to a platform above the house batteries. This allowed for 8 house batteries (8 x Deka 235 AH flooded). All the wiring originally done in the RV for DC was replaced. We did not have a single original wire, less than 3 feet. Now only the needed length of wire is installed, improving losses. When possible was 4/0 wire also used. Below is before and after picture.
Another panel added to the trailer for a total of 1000 watt. We are now charging more than 60 amperes from the trailer alone.
200 Watt of extra 100 Watt panels added to a total of 840 Watt on the roof of the RV. The extra panels ended up not providing any additional power since the poorly matched panels 160 and 100 Watt “12 Volt” panels had a different power curve.
Rebuilt the internal panels to have room for the extra monitoring of the charging from solar.
Added a single 12 Volt battery in the trailer to provide light and a small inverter for 120 Volt AC. The controller in the RV was replaced from 45+60 ampere to 2 60 ampere controllers and the 45 went into the trailer. A single 100 AH 12 Volt battery is being charged. Power from the panels can be switched between trailer and RV.
Replaced the “12 Volt” panels on the RV with Kyocera 265 Watt residential panels. Also added additionally 2 Kyocera 260 Watt panels on the trailer.
The Water tank was insulated and the 120 Volt AC is used with reduced voltage (60 volt AC) to heat the water in 4 hours. With the reduced voltage is the water heater not loading the inverter very high.
Working on a complete monitoring system for the battery and charging system. The Raspberry PI is collecting information and provide a website to show the information with graphs.
Another 265 Watt Kyocera panel was added to the RV.
Converted the battery system from 12 Volt to 24 Volt by reconfiguring the wiring, replacing the inverter with a 4000 Watt Magnum MS4024. A small breaker box was mounted because the new inverter did not have built-in 20 Ampere breakers. A Samlex 24 –> 12 Volt DC converter was added to provide power for the light and other 12 Volt loads, the converter provides stable voltage 24/7 and does not go up and down based on loads and charging. Everything for the change was isolated to the battery and inverter section of the RV. A small 50 Watt solar panel is used to maintain the voltage on the engine batteries when parked. Many changes to the DC wiring was done, the Generator is now started from the engine batteries.
Did some rewiring of the electrical 120 Volt AC in the RV, we can now run Air Condition and other things directly on the 4000 Watt 24 Volt inverter. The inverter has no problem starting the Air Condition even if we also use the Microwave Oven at the same time. But we have to balance the two phases to not exceed the 20 Ampere breaker. The wire is 12 Gauge stranded wire that can be connected the normal way (connect the plugs) or directly to an outlet from the Inverter.
Added a fifth Kyocera 265 Watt panels to the roof of the RV.
Replaced the Norcold 1200 firebomb with a Fisher & Paykel residential refrigerator. The best improvement that was done to the inside of the RV, we can now actually fit food a week and the ice cream stays cold. The new refrigerator uses 1-1.4 kWh per day and we can keep our propane for heating. We only need to refill the propane every second month in the winter and can run the whole summer on the tank. The Microwave was upgraded to a stainless-steel version too.
The steel trailer that weighed 4500 pounds empty was replaced with an all-aluminum trailer weighing 3050 pounds. The new trailer has the axles placed much better and provide less load on the hitch compared to the old trailer. To maximize the amount of energy captured was long SolarWorld XL 345 Watt panels added, covering 80% or more of the roof.
A battery box was added in the floor of the trailer to support 4 190 AH AGM batteries. A complete off-grid setup was added in the trailer with a Magnum MS4024 PAE inverter. This inverter can supply 240 Volt AC and we can run a large welder or even attach the RV directly to the 50 AMP circuit.
Bought 6 Battleborn 12 Volt Lithium batteries to replace the 8 Deka flooded batteries. The batteries dropped right in and adjusted charging to AGM and using no temperature adjustment. Going from 5.3 kWh to 7.2 kWh useful storage. The stable voltage from the Lithium also made for a lot of efficiency improvements.
Upgraded all the solar panels on the RV to SolarWorld XL 345 Watt panels. The total power is now 2070 watt on the roof of the RV. The panels are mounted on rails 6 inches above the roof to allow vents to open and skylight to still work as normal. Light still come through a solar panel so some light is still coming from the vents, but always like being parked in the shade.
Installed 4 battery modules from a Tesla Model S as our battery pack. Increasing the storage to 16 KWh of useful energy. The energy density is very high for the Tesla Modules. The same space that could have 8 flooded batteries with 5.3 KWh now house the tesla Modules with 16 KWh (20 KWH if we charged them 100%). The Tenergy 5 in 1 device is used to manually trigger a balancing on the cell each month.
Replaced a chair with an electric fireplace integrated into a new media center we built. Now running electric heaters in the morning. The Fireplace is wired to a special circuit that only allow draining the battery to 40% with the heater. This circuit reconnects when the charge level gets above 80%.
The AGM batteries in the trailer were replaced with 2 of the Battleborn Lithium batteries. When the battery box gets expanded a little more is 4 lithium batteries going to be used in the trailer.
Tested with MidNite Controllers for a short time. The controllers have multiple fans and the electric room is pretty dusty.
The batteries in the trailer were sold and new Battleborn CG6 sized was added, the capacity is now double.
The MorningStar controller had a hardware issue and only allowed 20 amperes charging. One of the spare MidNite controllers was used to replace. The trailer environment is much cleaner and less dusty.
An extra Tesla Module that had been used for testing was added to the battery bank for a total of 26.5 kWh or around 20 kWh of useful storage. The battery box is now lined with ¼ inch plywood to limit the chance of shorting a battery during mounting and insulation for lower temperatures.
The balancing was upgraded from the balancers that manually required starting a balance. The Battery Medics are now balancing the batteries when the voltage is above 24 Volt. This is at full charge so the loss of energy is only when charging.
The fluid container is also updated and now allow more than doubles the capacity.
The Raspberry Pi that use to only talk with the Solar Controllers now also tracks the Battery State of Charge using a custom board.
The data now allow the Excel spreadsheet to track the state of charge and the actual drain from the battery.
Got around to create a wiring diagram with Visio. Download the detailed PDF Wiring Diagram RV and Trailer.
We have had issues with the control board for the Waterheater since the spring of 2019. Control is now implemented for the 120 Volt Heating Element based on a simple sensor and relay bought from Amazon. An added benefit is we can now reduce the temperature and daily power required to heat the 10 gallons of water. This Water Heater from Solar blog has more details about the energy savings.
The software for the Raspberry PI system has been updated with small features constantly. After adding a MidNite WhizBang Jr. in the trailer can the screen also display the battery status in the trailer.
The data is captured every 15 seconds from the solar controllers and the shunt by the Raspberry Pi withExcel can a lot of useful graphs give an overview.
Daily RV Status
Daily Trailer Status
The 4 Battleborn Batteries had over time been more and more out of balance ending with one 12 Volt part being in battery disconnect when the other was not fully charged. A solution with a Voltage dependent switch and a resistor brought it back in balance.
The cover was also cut and a piece of plexiglass added to monitor from outside.
The MidNite Solar Controller was not performing very well when running in float under high loads. The battery was drained during the day when another RV was hooked to the trailers inverter. The MidNite Controller was also noisy under load with multiple fans. A 60 Ampere MorningStar Solar Controller with no fans was installed instead.
4 Additional outlets were also installed in the empty space of the breaker box with the 30/50 Amp outlets.
The internal display was showing the instant generation and consumption data. The information is now updated to also include the summarized information for daily kWh.
Wiring Diagram updated Wiring Diagram RV and Trailer
The original Sub=panel with two 20 Ampere breakers was causing problems when running high loads like the Air Condition together with other loads. When the breaker popped was other things disconnected like networking and refrigerator. The Magnum MS4024 is capable of 4000 Watt sustained loads and 5000 Watt for 5 minutes so disconnects based on only 20 Ampere (2400 Watt) watt, not a good solution. A new breaker panel with six 20 Ampere breakers with dedicated circuits for networking and base loads.
The box also allowed mounting additional outlets in the top so the Battery Heating is now connecting directly to the breaker box too.