A cool and quiet sailboat thanks to efficient air conditioning, LiFePO4 batteries, and Integrel

Ben Stein

Ben Stein

Publisher of Panbo.com, passionate marine electronics enthusiast, 100-ton USCG master.

9 Responses

  1. Fred Murphy says:

    Great article!

  2. Davejones says:

    Good article and would be very interested in seeing a followup when the system has been used more. It would also be interesting to know the type of cruising the owner does as it appears that the system could support less than two days at anchor without firing up the main engine for about four hours to get back to 80% SOC. Did the owner have any rationale for only being able to run the water heater on shorepower?

  3. Clay Duhon says:

    Great article. I have a similar victron setup 12v. Can you tell me what the (dc power) represents?
    Thank you

    • Ben Stein Ben Stein says:


      I think you’re referring to DC power in the picture of the Touch 50 towards the bottom of the article. If so, that figure represents the DC power the Victron GX (Cerbo on Cinnamon Girl) has calculated. It’s calculating this based on the points in the system it can measure. So, on Cinnamon Girl it can see how much power is flowing into or out of the batteries and how much power is coming from the solar controllers. But, there’s not a VE-connected meter on the output of the Integrel alternator. So, that’s calculated as part of the “DC System” and represented by that box. Incidentally, when that picture was taken, Integrel was generating power which is why the number is negative (and large).

      -Ben S.

  4. Bruce Schwab says:

    Having worked in the background with BoatRx on this project (providing the Integrel), we at OPE can say that they are awesome installers!

    Whether Integrel or other high-power alternator/regulator DC charging system, generator removal/replacement is becoming a popular option, and a growing percentage of our distribution business.

    Note that these systems are generally not DIY installations. We highly recommend only having such systems done by an experienced installer like BoatRx!

  5. Peter Christensen says:

    ..high tech over expensive systems that will require a 5 dwarf team of electrical engineers on board at all times to maybe keep it working.

  6. Anon says:

    Inspiring. Looking for smallest cost installation to be used for a smaller 24-30 ft sailboat.

  7. Ben says:

    I’d be very interested to know how BoatRX have overcome (assuming they’re aware?) the one major, and potentially catastrophic; issue with using Victron MPPT’s as DC-DC chargers?

    Under certain circumstances, a Victron MPPT will deliberately short the PV input terminals to protect the battery bank.

    This is completely safe if a solar panel is connected to the input, but not so with anything else.

    This behaviour is documented here under Err 38 and 39:


    Can you please check with BoatRX and come back to me?

    • Ben Stein Ben Stein says:


      I reached out to Victron to understand this issue before I published this article. As you mentioned, in certain circumstances the MPPT can short its output terminals. Here’s what I learned:

      If the output side stops accepting current rapidly (like a BMS disconnect event), the MPPT has to do something to stop the inbound energy flow. To do that, it will short the input terminals. If solar panels are connected to the input, that would just drop panel voltage to 0 and all would be fine. But, if the inbound source is a battery or other high current source, that won’t work. So, there’s an internal fuse in the MPPT that will trip in order to avoid bigger issues. Once that fuse opens, the unit is done, as it’s not economical to replace the fuse.

      I asked about potentially providing overcurrent protection external to the unit so that when the terminals are shorted that overcurrent opens first. They thought that could work but the magic is in the timing of which overcurrent protection goes first. In my conversations, Victron didn’t know the size or blow speed of the fuse used on the boards so it might take some disassembly or experimentation to figure it out. It’s also not likely to be an issue unless there’s a shutdown event during charging.

      Further, during my conversation I learned that Victron has plans to expand the DC-DC lineup with more 48-volt options (among others) but that the supply chain issues have consumed their product engineering resources in refactoring existing products for available components.

      -Ben S.

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