The third and final phase of our solar installation on our RV was installing an inverter to convert the 24V battery power into 120V for general receptacles and higher power appliances. We chose to install a Victron Multiplus 3000W inverter.
We also had to choose how to wire the inverter into the existing 120V AC system in the RV. We chose to install a transfer switch that would allow us to use power in 4 configurations:
1. Shore power only (Inverter Bypass)
2. Shore power to RV and Shore power to inverter to use it as a battery charger
3. Inverter power only using battery and solar
4. Hybrid power combining battery (and solar) and shore or generator
Disclaimer: While Tesla batteries are a very high quality and safe when handled and run within operating characteristics, if something goes wrong they can be quite dangerous. It is your responsibility to fully understand and make sure the system is safely programmed and installed if you choose to take on an install like this. Furthermore, this build is not endorsed or supported by any manufacturers of the compenents used in this build, and they may not provide support on an install like this if you run into trouble. I am not able to provide individual support on these builds. You might be able to find community support over in the Second-Life Batteries Facebook Group.
There are a few different ways the inverter could have been wired into the RV but we felt this would give us the most flexibility. This configuration however requires some monitoring as when running the whole RV you can easily overload the inverter if you attempt to run the AC, Fridge, Stove and other large appliances at once.
This is the schematic of how this is wired in our RV.

You can find a list of components in this blog post: Updated Tesla Module RV Installation You will notice that since our RV is a 50A split phase RV we needed to jumper the single leg from the inverter to power both sides of the RV’s breaker panel. The reason for this is explained further in the video we made on the install. http://www.youtube.com/embed/GKt9A93-CGY?wmode=opaque So far this configuration has been working very well for us. We love being able to power the entire RV including the AC through the inverter.
At this point our solar installation is finished! I am sure however we will be making upgrades and tweaking it in the future.
UPDATE: After running this system for a while I’ve made some tweaks to my design. Check out our post on Updated Tesla Module RV Installation that has a schematic and list of components I’d recommend for an installation.
Also, check out the previous 2 phases of our solar install:
Phase 1 – Installing the Solar Panels
Phase 2 – Installing the Tesla Battery module
*Note: This article contains affiliate links.
Start Your Solar Journey!
Thinking about adding solar to your RV? Start here with our solar calculator to get an idea of what might be right for you!
Become A Mortons On The Move Insider
Join 10,000+ other adventurers to receive educating, entertaining, and inspiring articles about RV Travel Destinations, RV Gear, and Off-Grid Living to jump-start your adventures today!
Leroi
Wednesday 24th of February 2021
Hi guys
There seems to be an error in this article (and maybe in any related video you made? (I haven't checked)); this Victron MultiPlus is a 2400 W inverter, not 3000 W. (Probably for marketing reasons, Victron call the unit a "3000 VA".) I'm shopping for a 3000W inverter and noticed the difference in their title and their datasheet states 2400W.
https://www.victronenergy.com/upload/documents/Datasheet-Multiplus-inverter-charger_2kVA-and-3kVA-120V-US-EN.pdf
Incidentally, Battle Born's website seems to have the same error.
I know you're into the details so, unless I'm wrong (please correct me if I am), you may want to confirm and then update the article.
Regards, Leroi
Mortons on the Move
Saturday 27th of February 2021
You are very correct, that was an error in the writing and many people make it. Its kinda a confusing topic as many inverter manufacturers rate their inverters with a power factor of 1, generators are the same.... since most appliances run PF of .6-.8 then yes 2400 watts is correct. You will find this issue across the board with manufacturers but its actually nice to see Victron calling it out correctly. I will go ahead and make that change.
Nigel
Tuesday 30th of June 2020
Edit, I just read ALL the comments above and I see you said your friends switch was the same but different numbers. I guess that pooches my idea. :(
Nigel
Tuesday 30th of June 2020
I'm hoping for a hail Mary here. I'm installing this tomorrow on Canada day. I would love to know if you fould tell me what wires go to which pole numbers the wires all go to. There's 12 terminals on this switch and I don't want to make a mistake
Jeff Ferguson
Tuesday 12th of May 2020
Tom I am using the exact same switch’s you installed in phase three. Baomain three positions. It would be a great help to know how to jumper the switch. I want it to do exactly what you did with it. Thanks.
Mike
Wednesday 4th of December 2019
I'd be curious to see your inverter and charging values in the multiplus. I'm building a remarkably similar system. Thanks