The 20k Project: Part 1 – The Plan for 20,000 Watt Hours

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“Plans are worthless, but planning is everything.”

– Dwight Eisenhower


People are often surprised that I’ll launch into a project without a plan.  And that’s true, I almost never write anything down beyond a few basic sketches or concepts.  But that doesn’t mean I haven’t done any planning, and that’s what this video is about.

This is the first of my videos on our 20k Project – the project to add over 20,000 watt hours of battery capacity to our new RV, the Winnebago EKKO.  I’ve actually completed the project already (I’m just late getting the video up), and I can tell you that not everything went according to plan, and I’ve already modified some of the finished project.  But that’s the nature of RV mods.  So look at this video as “bright eyed and bushy tailed James”, eager to get to work on his big project.

And be prepared to compare this to “downtrodden, cynical, and grizzled James” at the end of the project!


The video is really long, I give you that.  But you’ll learn what I had planned for the major electrical systems and components of this project.  You’ll also learn some of the reasoning behind why I did things the way I did.

I won’t rehash the whole project here.  That’s in the rather long video above.  But I will use this space to answer questions on the parts and materials used, and my thinking behind some of the decisions I made.  So ask your questions in the comments below, and I’ll do my best to answer them.

But I will give you some links here to the products I used.  The major ones anyway.  (Some of these are affiliate links.)


Those are the big things.  Other things… fire off your questions below!



James is a former rocket scientist, a USA Cycling coach, and lifelong fitness buff. When he's not driving the RV, or modifying the RV (or - that one time - doing both at once), you can find him racing bicycles, or building furniture, or making music. In his spare time, he works for a large IT company.

    141 thoughts on “The 20k Project: Part 1 – The Plan for 20,000 Watt Hours

    1. Martine

      James, you are an amazing gift to the RV world, and we are so fortunate to have you. I have been watching your vids for years and learned a great deal about RV mods, latest gadgets, etc., but the most important thing I learned from you, is that quality matters, and tenacity matters even more. You don’t let go, you don’t quit, you bounce back like a rubber ball after failures, and always the perennial optimist with so much positive energy. I love that about you. That is a fine human spirit, and this is what moves the human race forward. I am in awe of your accomplishments in every direction. You have a high level of education, you are a rocket scientist – the hardest of professions, you have the best RV in production in America with the most mods (heh, heh), you are in the best shape and do extreme sports, you have a lovely marriage with a lovely wife, AND you find time to make exceptionally good videos packed with rich content. What else have you not accomplished, wow! Please give yourself a good pat on the back from me, and a hug to you and Stef. Greetings from Silicon Valley in California. Well done, James!

      This was mostly over my head. I have zero knowledge of electricals, but… I will valiantly learn. You are an excellent teacher. This is a class build. Thank you for your time, and expertise.

      1. James - Post author

        And the award for this year’s favorite Fit RV commenter goes to… Martine!!

        Seriously though, glad you like the site. 🙂

    2. Sandy Depottey

      We are picking up our EKKO next week. We will have the one battery and generator configuration. I want to add a hard wired surge protector. Is the model that you have linked above the appropriate one for my configuration?


    3. Herb Nickles

      James, how were you able to (or where did you) buy the GTX320 Lithionics batteries. Everywhere I check, they say they are only available to OEMs. I have a Micro Minnie FLX on order which comes with one of those batteries and I would like to add a second.

    4. Jacques W

      After watching your videos and reading about the recent issues with the Ekko inverter/water, I like the idea of relocating the inverter. I also like the idea of having the batteries inside – that should abate the heat or cold limitation of lithium batteries. When considering moving the batteries, did you ever consider other areas in the coach? We don’t need as big of a garage so that came to mind, but I don’t know if relocating electrical components that far away is even possible.

      1. James - Post author

        The EKKO batteries are heated, so I initially looked at other storage compartments. But none of them were big enough to fit all the bateries together.
        Since the batteries are heated, I don’t really care so much about keeping them warm. But I was concerned about keeping them cool.

        The gear garage would work, physically, for storing the batteries. Honestly, if you’re going to do that, I would put the inverter back there as well, rather than having the long cable run.
        Then you could hang it on the wall, all the cable runs are short, and everything is right there.
        That’s actually not a bad idea.

        1. Jacques W

          Thanks for the reply. Do you think the batteries would stay cool enough in the garage? I’ve had the Volta on my T reach 115F one too many times in the Arizona heat only to have to drive up to Flagstaff for the evening (not a bad compromise).

        2. James - Post author

          On the one hand, the garage is heated, but not cooled. So that’s a negative.
          But on the other hand, it’s like 48 times bigger than where Winnebago puts the batteries in the first place, and they seem to think they’ll be fine.
          The batteries themselves will keep working to like 130F or something, so I *think* you’d be OK, but don’t quote me on that.

        3. Jacques W

          One idea is to hang the batteries from the garage ceiling (air flowing from above and below), but first I need to check the temperatures in the garage during the summer … IF I get my Ekko by then!

          I like the optimism towards WGO, but I’m not sure that they are considering these extreme temperatures – and the world is only getting hotter :-). In the Travato, the Volta hangs off the back but yet does not dissipate heat very well (bc of the insulation?). I think that being so close to the asphalt may actually increase battery temperatures. The Volta battery location is different in other coaches and manufacturers but this may have been dictated by space.

          Ultimately, my decision will come down to how much battery do I need to run the A/C in the extreme temperatures, as you discuss in many videos. I’ve asked the Ekko facebook group how well the (stock # of) batteries work during extreme summer usage but I don’t think many people have tried this yet (and you quickly upgraded to a pallet of batteries!).

          I like the ability to expand the system, but the stock placement of the Lithionics batteries in the Ekko makes that more difficult.

        4. Jacques W

          I’m running into a distance issue – especially with the second alternator. I can’t seem to find an easy way to wire the alternator all the way to the back. Would you have any insight?

        5. James - Post author

          An *easy* way? No. I don’t think there is one.
          I followed Winnebago’s original path for the large cables from the alternator. If I were going back to the garage, I would just continue to run along the frame rail on the driver’s side all the way back.
          You’d need super huge cables though – at 12v, that’s a long way to push a lot of amps.

        6. Jacques W

          Looks like the garage is a bit too far away from the alternator for this to be a great option. A 2/0 cable is likely needed to make that run without much voltage drop. Is this the reason batteries and electronics are placed closed to power sources?

        7. James - Post author

          Yep. That’s why.
          Although my run from the alternator to the batteries is actually 4/0 cable!

    5. Nancy Savidge

      James, I have searched everywhere for the Planet table, they don’t seem to be imported into the states. I have emailed the company directly and then tried to secure through an RV company here that does have them but they won’t sell it retail. Any thoughts?

      1. James - Post author

        I’d try calling Lippert. Like with an actual phone. That seemed to work better than email for me.

        1. James - Post author

          Yep, you’ll likely have to make contact with an actual human at Lippert to get this table leg. That’s what I had to do.

    6. John Plisinski

      James, Thanks for your reply. What is meant by a generator that is noise rated for National Parks? The EKKO’s generator is still quite noisy?
      I agree you always what to be courteous to your neighbors.
      For a pet that you want to keep safe in the heat of the day a generator kicking on during the day should not be a problem.
      I live in CT and the closet Winnebago dealer in MA still has not gotten a demo EKKO. When I finally get to see and drive one l’ll see if they would run the generator for me.

      1. James - Post author

        Well, since getting rid of ours 5 years ago, we sort of think all generators are noisy, and we don’t have them in our own RVs.
        But some are certainly noisier than others, and the one in the EKKO is the quietest RV generator we’ve come across.
        The National Park Service has a noise limit for generators. I believe it’s 70dB at 50 feet? Check me on that.
        The EKKO generator meets that specification. We’ve tested it.

    7. Kevin Scarbel

      This project is interesting, exciting, educational and more.
      James wants to go all the way, and I appreciate that. I usually do the same. Wanting that power capacity in reserve, when/should it be needed (not routinely), is reasonable and rational. There is a cost, but James and many others are willing to pay up for the capability.

      Rather than 5 batteries, Winnebago could easily fit 4 in the lower compartments (not inside the living space), 2 plus a Xantrex 3000W/150A Freedom XC Pro in the front compartment, and 2 more batteries in the rear compartment after its door and interior dimensions are changed to mirror the front compartment.

      A large number of Ekko customers would pay up for a 3 battery configuration paired with a Xantrex 3000W/150A Freedom XC Pro, because it would have a sweet spot price point paired with meaningful power capacity.

      1. James - Post author

        I think you’re right. A 3 or 4 battery configuration from the factory would appeal to a lot of folks who don’t want to undertake this level of project. At the least, I hope Winnebago redesigns that second compartment so it’s useful to others.

        1. StanLass

          Not being very electrical savvy I wondered why are you used 5 of the 320 batteries rather than using less of a larger size say the 630ah ones?

        2. James - Post author

          Interesting question. Initially, it was to maintain compatibility with the Winnebago-installed battery. I already had one… seemed simpler to just add more, rather than toss that one and do something else.
          Also, there aremore layout options available with 5 smaller batteries than 3 large ones. Since I didn’t know which way I would end up installing the batteries (like… which way would they actually fit in the rig) more options seemed like the smarter way to go.

    8. G

      I guess I missed “WHY” you would waste your money on 20K amp hours of batteries??? and there is no way to charge these batteries fully off 455 watts.
      if you were to use all 20k amp hours.. SO WHY???
      Not sure why you like to spend (waste your money) like this?????
      and to ask your engines alternator to charge these batteries either???

      What class/YouTube video did you watch???
      On it’s own you need 2:1, 3:1 MORE Solar : AMP Hours
      (900:300) Watts : AMPS) unless you are going to drive for 5-8 hours a day and use (wear-out) your Alternator. be my gest.

      Again, I missed WHY you think you need 20K Amp hours???

      1. James - Post author

        Why? Because I can.
        Someone once told me, “Just because you have a Ferrari, doesn’t mean you have to drive it every day.” It’s the same with a large battery bank. I don’t anticipate that we’ll burn through 20,000 watt hours regularly. Far from it.
        But, if I want to go ride a century in the summer, and want to make sure Mel the cat is going to be fine with air conditioning, I like knowing that I can. Absolutely and without worry.
        We previously had a similar system with 7,000 watt hours of capacity, and found it limiting. We don’t like those kinds of limitations.

        You’re obviously new to these lithium battery systems.
        As far as the mechanics of charging it, you don’t charge them primarily from solar. Solar is too weak and weather dependent to count on for charging. It’s a nice-to-have, and I do intend to make the most of it. But I’m more looking to it to keep up with day-to day loads. Not extensive periods of air conditioning.
        Nor do you charge these systems with the engine’s main alternator. The EKKO has a second alternator that is dedicated to charging the battery bank. It has a 170 amp capacity, and I’ve got plans to upgrade it at some point as well.
        The inverter/charger also has a 120 amp charging function, which we will use when we have shore power.

        But the point you’re missing is: on a day to day basis, I’m not likely to use much more power than the next guy. And it will actually take me much less time to charge!
        But it’s when we want to use the air conditioning for extended periods without hookups that the capabilities of this rig will shine. And those are the only times it might take me longer to charge up than you.
        Most of the time… I simply won’t be bothered thinking about my state of charge. I suppose that’s the real benefit. The battery resource will be so plentiful, and recharged so frequently, that there’s no need to watch it closely.

        1. John Plisinski

          I found out that you can have a generator auto start installed on the EKKO. The auto start could be set for either for temperature or low battery. The estimated cost would be about $800. How does that compare to cost of a second LITHIONICS battery?
          Also what would be the pros and cons.

        2. James - Post author

          Naturally, a Lithionics battery of this size and spec is more than $800. But it’s not about the cheapest way to go about things.
          The point is, we simply don’t want the noise, the fumes, the noise, the maintenance, the noise, the hassle, or the noise of dealing with a generator.

          Imagine it’s 6am at a quiet campground, and you want a piece of toast.
          With a generator, you have to wake up the whole campground for that piece of toast, and since you’re not supposed to run a generator for just 3 minutes and then stop it, you’ll be keeping the campground awake for 15 minutes or so. yay.
          Us… we just make toast.

      2. Mendez

        What a great undertaking, and plenty of power for the next grid damaged induced, Carrington Event. If you wire your panels in series, you will take advantage of low sun angle energy harvesting, given Victron’s MPPT Controller only needs a 1 volt of differential between Solar input and Controller output for it’s internal DC/DC converter to operate. Said another way, even at low sun angle, there will be enough voltage differential to still harvest energy. We have witnessed this repeatedly. Thanks for sharing your project.

        1. James - Post author

          Interesting you say it works with only a 1 volt differential. Victron themselves say 5 volts difference is required. But hey – even better, right?!

    9. Veritea

      Hi James,

      Just a quick note to say that you may want to reconsider the way you are planning to interconnect your batteries. The method you describe perfectly balances the current when you have two batteries, but when you add more the interior batteries experience substantially lower current draw relative to the exterior two batteries. Not intuitively obvious but you could see it if you modeled it in SPICE. Here is an article describing it along with suggested alternative interconnect methods that will provide balanced loading. Y

      1. James - Post author

        Interesting, and the loads resemble what I see in the field.
        Let’s table this for now, because there are some wrinkles coming up that may influence this discussion.
        Hit me up at the end of the series and we can explore this further.

    10. Mike Collins

      You didn’t list the 250A DC circuit breaker for me to check specs. When you parallel all the batteries you are going to have a massive short circuit current to deal with safely. The interrupt current of the breaker is going to be important as well as the time lag on interrupt.

      For my 14000 Watt hour system (10 X 110AH trojan trillium) I put 200A MRBF fuses on each battery and then a final 350A class T fuse on the combined set. All my battery are connected with silver plated copper 2 X .25 buss bars…i.e. no wire. I also added 300A blue sea switch after each 200A MRBF so I can test the system with 1-10 batteries. The MRBF’s limit the combined current to 2000A and the final class T is about the best for interrupt current.

      You better use a torque wrench on all the high current connections or your asking for trouble.

      1. James - Post author

        I didn’t include the circuit breaker in my list because I didn’t buy it. It came with the Lithionics battery and the EKKO and is required for the system to maintain its UL listied status. Apparently, the specs for interrupt current were sufficient to satisfy UL, but I can’t say what they were. I am glad for the breaker instead of the usual collection of “frankensteins’s laboratory” looking fuses and switches.

        And clearly, you don’t start a project like this without knowing how to properly use a torque wrench. (I used two!)

        1. Mike Collins

          I would have like to use a breaker too, but not safe. Your max short circuit current from the batteries will vaporize the 4/0 cable, buss bars, … so I would have concern.

          At a minimum I would add a class T fuse and have very close to the combined battery connection. Any short at that point, you will have a big problem. Physical protection at the point is also very wise. I used insulation on that area and polycarb shield. Hopefully you could drop a wrench in there and not burn the van down.

        2. James - Post author

          I take exception to this.
          I don’t think it’s fair to say something is “not safe” when you’ve admitted you don’t know what it is and what its capabilities and specifications are.

          At some point, you have to rely on testing and certification done by others. (Even accepting the ratings on a class T fuse takes a bit of faith.). Underwriter’s Laboratory completed thorough testing to verify the safety and functionality of the components. Besides just the breaker carrying a UL listing, the battery system as a whole was tested for motive applications.

          In short, I’m satisfied with the safety of the system. Between the protections built into the BMS on each battery, and the circuit breaker, Underwriter’s Laboratory – who require redundant safeties for things like this – is also satisfied.

          I went back and dug it up. The breaker is covered here:

        3. Mike Collins

          The UL rating is for the battery not the system design you are doing. You have 4 batteries and missing that you have to evaluate the design for safety. I am just trying to be helpful and save you troubles.

          Your GTX320 batteries have 5818A bolted-fault current; 4 in parallel is 23272A. Hope your breaker can handle that. Most excellent breaker are 10-15K A for interrupt current; 4 batteries exceed that. Class T are 200KA. That is the interrupt problem.

          The next problem is the GTX320 spec’ed at 1200A for 1sec. This is operating . For 4 batteries that makes 4800A for 1 sec on the 4/0 cable to the breaker. Not sure what the breaker time vs overcurrent specs are but usually much slower than a fuse. You decide if your cables,… can take that level of current over the longer time. Likely a big problem you are ignoring.

          One last minor comment on physical protection: not a great idea for hold down on top posted batteries to be conductive. I use FR4 (firerated) L section for top holddown. If you really like the steel: please cover with shrinktube. Just trying to help keep you safe.

          I’ll quit on the comments, good luck and have fun !!

        4. James - Post author

          It’s strange that the part of this that you’re objecting to is *specifically* the part that is certified to work with the Lithionics battery – as a system – by UL. See here:
          This is also literally about the only part of the system that is installed by Winnebago that I am retaining. Even the steel hold down strap is something that Winnebago does in stock EKKO.
          The breaker itself has an interrupt rating of 100,000 amps. Well more than 23k.
          Likewise, the specs on time etc. are in the link I provided, and to save you from having to look it up, at a current half that of one battery’s 1200A, it would trip in less than one tenth of one second.
          Like I said, if UL is satisfied, then I’m satisfied.

          You’ll have to wait for the remaining videos to see if the system is installed according to this plan. (Spoiler, it isn’t 100%.)
          And if we get into it any further, it will spoil the surprise. SO… On with the project!

        5. Kevin Scarbel

          Both of you come to the table with experience.
          If the folks at Lithionics are good with the installation architecture of Jame’s system, then I’m good with it.

    11. Don NOrush


      Why not 50A from the very beginning as suggested “All About RV’s” before the MultiPlus II?

      It will not only eliminate the 30A AC breaker, but also it will take full advantage to 50A input if one is luck enough to connect to.

      1. James - Post author

        I thought about it, but decided against it for a few reasons.
        First, it’s a small coach. There’s one air conditioner, and no two phase appliances. I would have been hooking up only one leg of the 50a plug-in anyway.
        Second, it would have meant carrying a 50a shore power cord, which I don’t have. Those cords are larger, heavier, and more expensive – especially if you want a long-ish one. In addition to the cord, I would have had to purchase a more expensive shore power inlet, and more expensive surge suppressor. And more expensive and heavier cabling to run between them all inside the coach.
        Third – we prefer to be not hooked up to shore power if we can avoid it. We’re not really RV park kind of travelers. That’s a big part of the reason for undertaking a project like this. And there are a lot more places (at least that we might go) with a 30A hookup instead of 50, which would have meant using an adapter much of the time.
        But finally… I already have 50A capability! The load support feature of the inverter will give me 50A when I want it (which isn’t often).
        For all these reasons, I decided to just stick with the 30a shore power connection. Easier, cheaper, lighter, and accomplishes the same thing.

    12. Walter van Korven

      Hi James,
      I was just wondering if the large capacity of the 5 parallel batteries could overload your alternator or is the Balmar regulator installed in the engine bay limiting the charging current to the batteries?

      Thanks in advance for any info on this


      1. James - Post author

        Good question, and thankfully the answer is no – at least according to Balmar and Lithionics.
        The charge controller is responsible for regulating the charge. It has temperature sensors for both the batteries and the alternator.
        Unless it goes faulty, things should be fine!

    13. Ken Fetter

      the one thing I don’t see listed is that dryer vent stuff. I need to replace my heater duct work and that looks like it had a bit on insulation it. can you send me a link to that so i can see if it will work for my heater duct.
      Thank you

      1. James - Post author

        Why would I?
        With the exception of the cables to the second alternator, all my cables are less than 5 feet each. So there’s no significant weight savings. That’s usually the big advantage of the 48v systems.
        I’d have fewer choices of inverters, I’d have to replace my alternator with a 48v one, and I’d also have to install a DC-DC converter to get 12v for the lights, etc.

        1. Shaun Simpkins

          Volta uses 48V for a ew reasons:
          1.) smaller alternator (lower current for equal power)
          2.) better efficiency in inverting to 110VAC
          3.) lower wiring weight and smaller size.

          All this makes perfect sense in a work or emergency vehicle with high and continuous 110VAC loads needing to be efficiently sourced, but most RV loads are 12VDC. Getting rid of the 48V-12V DC-DC converter makes for simpler, more efficient and reliable rig power at the cost of inverter losses when the A/C or uWave or cooktop is on, which is not all the time. About the only disadvantage of a big-battery system with a 12V bus in a smaller rig is charging speed. But you rarely need that.

    14. Tae Lee

      Hello James!
      Are you going to do any upgrade on suspension system since you added additional weight on factory installed shocks?

      1. James - Post author

        An air suspension upgrade is already completed. Video coming.
        But we didn’t add as much weight as you might think. (Just removing the airplane seats bought us 114 lbs, for example.)

        1. James - Post author

          Speaking personally, I love the way our EKKO drives, and wouldn’t want to lift it.
          (Plus, we’re road cyclists… we need roads!)

        2. Kevin Scarbel

          I agree James, I don’t want a high center of gravity. And, a high lift (e.g. Revel) allows for more turbulence under the RV resulting in decreased fuel economy.
          Still, because the AWD Transit appears low and… is AWD, I want somewhat better approach and departure angles. It still won’t be as high as an AWD Sprinter.

    15. Kevin Scarbel

      There’s a rumor in Dearborn that Ford, now basking in the “outdoor” spotlight with the mid-sized Bronco Sport and full-size Bronco, is in talks to buy Winnebago.
      I will say that Ford’s R&D capabilities, quality control capabilities and massive nationwide dealer (service) network would be a game changer for the Winnebago brand.
      The AWD Ford Transit Ekko could be the first of many new products.

    16. Timothy Disbrow

      Once you get done with batt project, I’d like to see you try out the 4 season ability of the Ekko. Like a week or 2 in Wisconsin in the dead of winter w/ sub-zero (F) temps. That would be the real test of the Ekko’s design. Thank you.

      1. James - Post author

        OK. But what would we DO in Wisconsin in the dead of winter for two weeks??!!??
        Wouldn’t be much road riding, lol!
        I appreciate the testing aspect, but I’m not too crazy about just sitting in the van for a week or two.

    17. Fred Gross

      Perhaps I missed something on the battery cable sizing. Is the 4-0 cable because of the distance? I’ve always used the same gauge wire between batteries as the + and – main battery feed cables.

      1. James - Post author

        Distance and current, yes.
        The current internal to the battery bank won’t be as significant.
        I did check this wire sizing aspect with the engineering staff at Lithionics before going forward with it.

    18. Don Kane

      Interesting video. I did not scroll there all the comments, so I hope I’m not repetitive.

      Comment: My electrical system is also mounted on wood as you plan to. I wonder if that was wise. (I don’t plan to change it thou)

      Okay, now some mathy geeky questions:
      For a 90% discharge of your 20K system, what is the time to recharge to 100% with:
      1. B to B (from your alternator)
      2. solar present.
      3. solar future.
      4. shore.
      For fun, I would really be interested in your calculations. I mean, your mathy geeky calculations.

      So, for our rig, we plan a 100 (someday 200) Ah battery, and we have 30A chargers for BtB and shore. So, for 100 Ah, we could charge in less than 4 hours, with either system.

      For solar, we have two 175 W panels. We pull 650 Wh/day routinely, that is about 50 Ah of charge. But it seems the system slows down/shuts down when the batteries are charged, so I think we could get more per day if we needed it. But, for sure, two sunny days, we would be charged.
      Winter, maybe not.

      1. James - Post author

        If I were to run my batteries completely down to the 10% reserve cutoff, it would take a rather long time to recharge, from any source. But I haven’t done that yet (even while trying), and I don’t see that as being a common or likely scenario at all.

        From the second alternator, it would take about 8 hours. But that’s just a guess, because the alternator output varies with heat, engine rpm, and other factors. From shore power, it would take about 12 hours. From solar, it would take a really long time, and would depend on a whole lot of things.

        But the bigger take away is that, on a day to day basis, if I use just as much power as the next guy, it will only take me as long as – and probably less time – to recharge.

        1. Don Kane


          Actually, I was thinking you would not normally run it down, unless you were on a long _hot_ bike ride. But that would be worst case.

          And the combo of alt and solar would be even faster charging than your figures above. (Hey, weren’t you supposed to show your work?)

          On the other hand, you _are_ a higher rate user–induction stove, microwave, daily AC–so you might be over “normal” solar much of the time, even with your planned solar addition.

          On the other other hand (third hand?) you tend drive to locations and not stay weeks there, so the alt is a normal recharging source.

          Anyway, will love you in the “no generator” loop at camp grounds!!!

    19. Kevin Scarbel

      I’m thinking that if Winnebago could/would offer a three (3) battery configuration (GTX320) including the Xantrex 3000W/150A Freedom XC Pro, that would satisfy most discerning Ekko owners insisting on a high-spec electrical system.

    20. Scott

      Very nice thorough walkthrough and well thought out plan. Have you considered adding a Victron Cerbo GX, touchscreen, and smart shunt? Then you will have a very nice monitoring and control solution. Plus the Cerbo can connect the whole system to the internet for remote monitoring and control.

      1. James - Post author

        I looked at the Cerbo, but it didn’t really grab me. Battery monitoring through the Lithionics app is more than sufficient, with more data than would be available through a shunt.

        1. Manny Estrada

          Do you know soneone who could retrofit a lithium setup & a cassette toilet in El Paso on a 2017 Gemini 23TR?
          Thank you.

    21. Phil

      James – great video! I especially liked the 3D-printed battery hold down spacers since I’m in the planning stage for replacing our two 100Ah LiFePO4 batteries with one Lithionics 315Ah battery (same model as yours) in our 2017 Pleasure-Way. Would you be willing to send me the 3D printer model file for the spacers?

      Thanks for the idea, regardless!

    22. Patrick Broos

      Hi James. In the upcoming installation videos I hope you will spend a little time talking about the potential hazards inherent in any large battery bank (whether lithium or lead acid).

      I think it’s important for viewers to understand that you have significant technical experience (in the aerospace industry), you have read and understood the manuals for all this equipment, you have no doubt done plenty of other reading about DC power systems, and you have access to experts in the industry (e.g. at Lithionics and Victron) when needed. With your skills and knowledge, I have no doubt that you will achieve a safe design and installation.

      However, I worry that the typical viewer with more modest DIY experience (like me) can easily underestimate the hazards that can arise from design mistakes, installation mistakes, and accidents during operation.

      I feel that DIY experience with household AC wiring and with low-power DC distribution wiring does not really prepare anyone to do a project like this, unless they first take the time and effort to learn many things—as you have done.

      1. James - Post author

        I’ll mention where applicable… Though I don’t exactly expect anyone to follow along on my project.
        I’m not really thinking these are a “how to change a light bulb” kinds of videos!

        1. Patrick Broos

          Although my post expressed general concern about the hazards of any large battery bank, I definitely appreciate the several safety advantages that a Lithionics system has over a typical lead-acid system, including:

          1. No exploding hydrogen gas.

          2. No corrosive acid spills.

          3. Since Lithionics batteries can be switched off, NO part of the installation process (or maintenance work) has to be done on energized components.

          4. In a short circuit accident each Lithionics battery should (according to spec sheet) produce no more than 1200A for no more than 1 second (when the BMS shuts down the output) . I’ve seen reports on the web that a shorted lead-acid battery can produce 5000A initially, and will of course continue to supply power until it’s exhausted (or destroyed).

    23. Ian F

      I’m sure this will be a fun series to watch. Since so far all of my questions have been asked and answered, I’ll just offer my prediction on bleeding.
      Next video.
      Have fun and try to stay cool!

    24. Michael

      Did you consider diverting the forced air exhaust from the inverter compartment into the people space for when you’re camping in the cold season?

      1. James - Post author

        I did think about a cabin air exchange.
        There is a lot of steel in the floor in that area (for mounting the seats). Plowing a hole through that would have been arduous, for very little gain.
        In the winter, I doubt the compartment will get hot enough to be of any use inside.
        And in the summer, the last thing I want is to pump that air inside… and I have no interest in switching vents around every time I switch from “cool” to “heat”.

    25. Todd Shearer

      Great videos and resource. I admire how you are constantly pushing the limits Can you share further details on the shutoff switch used to isolate the solar panels. Thank you.

    26. Wayne Mitchell

      Great video as always and a setup like I have been planning. I am a bit disappointed you didn’t use SmartPlug’s ELCI/breaker combo for your shore power input, stop any hot skin condition on Number One.

    27. Kevin Scarbel

      The 20K project is all about not having an Onan (gasoline) generator. I myself don’t care for Cummins-Onan generators nor Cummins’ after-sales support.

      The question is begged, why doesn’t Winnebago offer a Honda generator option, the benchmark gold standard in generators. The newer inverter models are quiet, high-performing units delivering Honda’s legendary trouble-free service.

      Honda is America’s “go to” for generators. Why Onan? A generator isn’t a bad thing to have around, if it’s a Honda.

      1. James - Post author

        Literally zero RV manufacturers offer a Honda generator option. Because, unless something has changed, Honda doesn’t make a generator model that’s rated to be permanently mounted and wired into an RV. Liability and warranty issues kill that idea quickly. An end user can do whatever they like, however.

        1. Shaun Simpkins

          I suspect that it’s also a matter of market size. Honda could probably sell 100x the general-purpose generators than it could an underfloor-proportioned generator for permanent mounting in an RV.

          Cummins/Onan caters to the speciality generator markets, at an appropriate premium. Further, their new “quiet Onan” generator, a variable-speed injected inverter type like the Honda, is a pretty good unit which would dampen the demand for a Honda product.

      2. Dany Grondin

        Great Video..
        Can I ask you where did you find all those Cables, the 32A Breaker and the nice Solar Switch ?
        I about to do some purchases 🙂
        Thank you James for your work!

    28. Kevin Scarbel

      After much thought (all last night), it’s obvious that it would be effortless for Winnebago to make the Ekko’s rear enclosed compartment (generator deleted) with the same size door and interior dimensions as the front compartment, albeit shorter in length but which is still abundantly long enough for GTX320 batteries.

      Which begs the question, generator deleted, why did Winnebago make a virtually useless rear enclosed compartment with a smaller door and interior dimensions???

    29. Graham Smith

      A question on the solar… What I have seen from Zamp says the 3 port roof cap is limited to 170W / port or about 510W / 30A total. Won’t you have to replace that cap in order to go to 4 x 170W as planned?

      1. James - Post author

        By wiring the panels in series-parallel, you can increase the voltage and not the amperage. This gets you around the limits of the combiner box.

        1. Graham Smith

          And and by switching to MPPT you can handle the higher voltage of series connections. I experimented with series vs parallel vs series/parallel with my Travato KL and had some interesting results. There are definitely pros and cons to each and I will be interest to see what kind of results you get. One particularly strange issue revolves around partial shading of one panel in a series. The panels used seem to be what impacts that and I’m not sure how the Zamp 170W act.

          It’s also my opinion that if the solar wattage is below a certain level it seems as if it isn’t doing anything when in fact it is. But because it’s below normal usage (fridge, electronics, etc) it isn’t noticed. Getting it high enough to account for normal use and still add charge makes it appear much more useful. I have 315W now with my KL and can watch the charge go up on a sunny day. I expect that 455W will be an improvement. But, I really think WGO made a mistake by not going with 3x170W on the roof and a 40A controller which would allow for an external panel that could be positioned to face the sun.

        2. James - Post author

          That’s one of the things I LOVE about the Victron controller. The Bluetooth app for it is AMAZEBALLS!
          You can see both the panel and system inputs and outputs, volts, amps, etc. Super cool.

    30. Scott

      Great video guys! Very helpful for my build. One question…where can I find one of those little 32A circuit breakers + enclosure? Thanks!

    31. Graham Smith

      While I suspect I could, with some assistance, complete this project; I would need a tanker truck of coffee and a trainload of Twinkies to get me wound up enough to just get started. As the saying goes, “You’re a better man than I, Gunga Din!”

    32. Bill Babbs

      I follow your projects on YouTube, I can afford most of what’s needed for this project, but the only show stopper is the batteries that your using for this project. At $5K a pop, its not feasible for the average joe to afford them, I know what your going to say at this point, is use something cheaper. Continue on with the great videos, looking forward to next one. Thanks for your time

      1. James - Post author

        I hear you.
        I don’t actually expect anyone will follow along with my projects verbatim.
        I like to think that I’m just showing people what’s possible… and giving them ideas they can incorporate in their own way.

    33. Kevin Scarbel

      Has anyone pegged the dimensions of the would-be generator location, when configured as an enclosed compartment with the generator-delete option?

      That is, could two more GTX320s be installed there for a total of four ?

      1. James - Post author

        I won’t say never, but you could not fit the batteries in through the door of that compartment.
        You would have to destroy that compartment and develop something on your own to put the batteries there, either by making yourself a new door, or winching the batteries up from below.

        I thought about it, and then realized it was worlds easier to just bring the batteries inside.

        1. Kevin Scarbel

          The second compartment needs to have the interior height and depth as the front compartment, which is easily accomplished by Winnebago.
          The second compartment being shorter isn’t a problem as it appears the battery would fit lengthwise.
          The second compartment battery location solution appears to be the easiest and cheapest way for Winnebago to offer three and four battery (GTX320) quantity options.

    34. Kevin Scarbel

      As promised, you explained why you replaced the Xantrex 2000W/80A spec Freedom XC with a Victron Multiplus II Inverter Charger 3000W/120A(120 amp?), instead if a 3000W/150A Freedom XC Pro. (video 7:00 – 11:00)

      For folks who stay with the factory two battery (GTX320) fitment but want to be above the cost-driven “just enough to meet requirement” Xantrex 2000W/80A spec Freedom XC, I wonder in that scenario what would be the prudent replacement, the 3000W/150A Freedom XC Pro ($1200), or the Victron Multiplus II Inverter Charger 3000W/120A ($1500) ?

      1. James - Post author

        Replacing the stock inverter/charger with the upgraded Xantrex will save some coin, as you point out.
        But the bigger benefit of staying with a Xantrex is the physical size of the unit.
        The 3000 watt Xantrex is a comparable size to the 2000 watt, making it almost a drop-in replacement.
        The Victron is rather different dimensionally, and would necessitate tearing up compartments in order to fit it in.
        You’ll see what I mean in the next video.

    35. Robert Urban

      Hello, love your videos! How much weight did you add with this system and what did you have to subtract weight wise to accommodate it? Thanks!

      1. James - Post author

        I was working on multiple mods at the same time, so I can’t say exactly what *only* the 20k project added.
        But I do know that with the 20k project installed, and us full of water and loaded up for a long trip, we still had hundreds of pounds of capacity available as we rolled out of town.

        Oooh… and also… those automotive seats I removed were 114 pounds by themselves!

    36. Scott

      Thanks for laying this out – and spending all this money so I don’t have to!

      Two things I really dislike about my Travato 59KL, both related to the inverter/charger:

      First it creates a bunch of noise and heat inside the rig. It often seems like when we run the A/C it spends most of its time cooling the inverter/charger! Super nice the EKKO has some external space for that thing, I think that will make for a much better experience.

      The other annoyance is that everything runs through the inverter/charger – I’d really like to have an option to run shore power directly to the PD panel and bypass the inverter/charger.

      Have you considered an having a switch that would by-pass the inverter/charger when using shore power?

      Looking forward to what comes next!

      1. James - Post author

        Never considered a switch to bypass the inverter/charger. Ours has ample capacity, and since it’s also the battery charger, we kind of want it running.
        What’s your reasoning for wanting to bypass it? If it’s the noise and heat, I think I’ve got those handled.
        If it’s something else, I’m genuinely curious.

        1. Ross

          I don’t know about Scott, but for me – in extreme conditions (below zero, above 110) I would like the 120VAC to be provided strictly from shore power rather than having to go through the lithium systems because they can go into too cold/too hot shutdown. I have in fact experienced this. I even went so far as to sketch out a contactor-based switch for my 2019GL but have never implemented it.

        2. James - Post author

          Interesting. I understand now.
          Once the batteries are charged up, they should be more or less out of the equation. At least they are in my system…
          I suppose they could use a little current to keep them warm in winter, but mine are inside, so that will be minimal.

          So the problem is really an inverter over-temperature problem. (I don’t think inverters can get too cold.)
          Seems like you’re saying even in pass-through, your inverter/charger can overheat? Ouch!
          I was able to run my AC off of batteries on a 110 degree day for over 14 hours, and the inverter didn’t get too hot.

          I don’t think I have that same problem, but I understand yours.
          Have you contacted Volta for suggestions? I’d be curious as to what they’d say.

        3. shaun simpkins

          When a Pure 3 system is plugged in the 110VAC system loads ARE directly connected to shore power, but the system will always try to keep the battery charged using “excess” shore power capacity. The definition of “excess” is what MAX BRANCH AMPS is for.

          The Pure 3 system is designed to be as fully automatic as possible, and this introduces peculiarities in the system architecture whose purpose isn’t obvious. A hard-wired 110V switch would actually be a disadvantage because the Pure 3 system uses a modified “one tank” approach to sourcing rig loads. This allows the system to automatically revert to battery power should shore power drop.

          But there’s a further gotcha: 12VDC loads (which include the system BMS as well as the fridge and lights) are sourced solely from the battery pack, and it is possible to substantially drain the pack over several hours. By running the shore power through the inverter/charger/ATS, the system will automatically keep the battery pack charged, and guarantee that its BMS will always have the energy it needs.

          When on shore power, the Pure 3 inverter is actually on standby – what you hear is the charger turning on the box’s cooling fan, which the inverter and charger share.

    37. Peter

      There are no right angles on the human body. Consider the ergonomic shape of the “L shaped bench seats” you build. They will quickly become uncomfortable over time regardless of how nice they look. Well made commercial dining booths and their upholstered shape and contours are good examples. Another example shape is the drivers seat.

      1. James - Post author

        The walls and seats of the dinette will be at right angles of necessity. I did investigate making them at a reclined angle, but ruled that out because it would have taken up too much space.
        (The “run” of the seats would need to be considerably longer to get the angles desired… and there’s just not that much floor space. Plus, there’s a window along one side.)
        Comfort issues will be taken care of by variable densities in the upholstery.

      1. James - Post author

        Absdolutely not.
        Lithionics batteries are Lithium Iron Phosphate batteries, which can’t go into thermal runaway.
        They’re the safest batteries you can find.

    38. Rich Burguillos

      Exciting… love this electrical stuff. Thanks for sharing the build. I remember getting a sneak peek of the build in one of your earlier videos. I was wondering about the seats. At first I was worried your removing what I assume to be DOT approved seats both belts. But then I realized most RVs / Vans have seating of one type or another with no belts. Guess it’s a use at your own risk scenario while in motion. Personally I did not like the original seats or the table. Looking forward to the rest of the series… I would wonder what the total cost in materials would be.

      1. James - Post author

        Yes. I suppose I did remove some margin of safety with those seats. There was A LOT of steel holding them in place. Winnebago did a great job with that, and people should feel safe letting their children ride there.

        We, on the other hand, never travel with others. Those seats weren’t a benefit to us. What I eventually came up with does provide some measure of safety that I’m comfortable with for the limited times we use it.

        1. Kevin Scarbel

          So Winnebago needs two additional floor plan options, both offering encompassing four or five GTX320s.
          One floorplan would retaining 4 person seating for the pop-up customer with kids.
          The other floorplan would cater to the two-people customer scenario, Class B couples crossing over to Class B plus for additional space without bulk.

    39. Chris and Jean

      Hello James! My wife and I love your channel. Been following for awhile (since the first black tank experiment). I’m starting our battery/solar upgrade project on our 50amp motorhome. We are installing the same inverter/charger, though split phase in and out. Can you provide a link or manufacturer info on the 6/4 cable you used. I am planning to use 6 awg THHN in flexible 3/4” conduit (since that is what Newmar used) to/from the inverter. The 6/4 cable you used might be easier for me to run (30’ each direction). Thanks again for all you and Stef do (and Mel too!).

    40. Jim

      I love all the stuff and ideas and I know from last vids spoiler it’s mostly if not all done by now. Curious, and I understand why you wouldn’t want to disclose this, but this system has to cost at least 1/4 to a 1/3 cost of the rig with all the premo products. That being said, I wouldn’t publicly disclose the price as I wouldn’t want to face my wife’s wrath even though she’d be the prime person to benefit from all the extra power.

      It’s just my opinion, I think you made the battery tie down way more complicated than it needed to be. Personally I would have bolted a ratchet strap to the floor in two places and done. I’ve held 8 ton artillery pieces in place with those, they should be able to keep 5 batteries in place.

      Still geeking out about this project in fact have forwarded this series off to a Showhauler and Spacecraft MFG reps I know so he can see the potential of rocking a power system out.

      1. James - Post author

        Well, I actually haven’t added up a final price tag… and I don’t think I’m going to. I don’t want to know!!

        As it all turned out, the battery hold down was not too complicated in the end, and only required one hole in the floor. That’s a ways off in the videos though!

        Thanks for forwarding our video along!

    41. Dano

      I’m glad the one drawback of the system was acknowledged at 22:54 and that is when the batteries with that much capacity get low, its going to take a while to get them fully charged again.

      1. James - Post author

        True that.
        But day to day… if I use the same amount of electricity as you, it will only take me as long to charge as it takes you.

    42. Matt Gross

      Really looking forward to this install. I’m a huge fan of Victron Gear so this is going to be awesome! Victron is going to be adding a secondary monitoring system for DC charge sources outside of the Victron ecosystem, so you may want to look into adding a smartshunt on the Alternator line so you can see that information on the Cerbo on VRM. It’s not released yet, but it’s currently in the beta software of the Venus OS. Maybe these videos are already months behind, but something to think about if you want to track all your charge sources.

      Side note, I’m in Las Vegas which is pretty close and I’m building out my own DIY promaster next year to replace my last DIY van. I’ve been looking for bucket seats and if those are just going to sit around collecting dust, please email me if you plan on selling or donating to a good cause…my cause 😉

      1. James - Post author

        Interesting. Up until now, we’ve just been using those seats as “redneck porch furniture”.
        I’ll check with Stef and email you separately if we might let them go.

    43. Ken

      Hi James,
      Looking forward to seeing this play out! One thing I’ve been thinking of adding is a switch to turn off the alternator charging of the house batteries. In the event I
      know I’ll be plugging in at my destination it would provide the option to take the load off the engine and improve my fuel economy. I plan to make it reset back to charging from the alternator once I turn the engine off.
      Would appreciate your thoughts and the community on the matter.

      1. James - Post author

        The switch itself might be easy enough to install. I wouldn’t worry about that. But then you’d have to also worry about switching all the other connections to the alternator… temp sensor, FCC, etc.

        Honestly though, on the EKKO, the Balmar charge controller is easily accessible if you pop the hood.
        If I wanted to do what you’re seeking, I would just pop the hood, and unplug the charge controller. (It’s just a multi-pin plug.) Problem solved!

        1. Marv

          Just wondering why you didn’t go with the Victron DC-DC charge contoller(s) to replace the Balmar (of which I’m not familiar) seeing as you could add multiple ones to get up to 90A (If I remember right) of alternator charging capacity. Was it just that leaving the Balmar in was easier?

        2. James - Post author

          Well, yes, leaving the Balmar in was certainly easier.
          The second alternator is also made by Balmar, and provides up to 170 amps of charging current (we’ve personally seen this much). The charge controller programmed to work with it.
          At some point, I may add a DC-DC charger to capture any excess charge from the Ford alternator. Thus far, we haven’t seen a need for that. (But it sounds fun.)

    44. Dave Patterson

      After listening to your video, I admit I like a most of what you have stated that you have planned. I have only have one comment… A Shunt.. (Victron makes one which will fit into your system via the Lynx system, amongst others) which has uses for monitoring your system.

      1. James - Post author

        I thought about installing a shunt, but the Lithionics batteries transmit detailed telemetry data via bluetooth to a phone app.
        The data available directly from the Lithionics app is very detailed. I just use that.


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