FPB 97-1 All Charged Up: Solar Report From Mark Fritzer

#1 Battery

Hi Everyone! I’m freshly back from a trip to Whangarei to do some testing on the 97 prior to delivery. While Todd and Sarah relaxed in the boardroom with flat whites enduring endless meetings, I was able to get aboard the 97 and do some eagerly anticipated testing of the electrical system. For starters, the boat is amazing. Circa has done a fabulous job of taking the vision and turning it into reality, many kudos to the crew.

Now to the fun stuff…The 97 has a large, 2000 amp-hour traction battery bank aboard giving us a ton of storage capacity and range. Between our standard Electrodyne alternator setup, which we know has the capacity to deliver up to 600 amps of charging capability and our solar array, we theorized a potential output capacity upwards of 790 amps.

How awesome it was to record 898 amps during one of my tests!!

#2B Solar Array lower

We worked closely with Salt Service of Florida to come up with this array.

#3 Solar array fwd. upper
During the design phase we calculated that our 20 Sunpower 320 Watt * panels had the capacity to deliver 195-200 amps of charging capacity at 28.8 VDC (which included the inefficiencies of the charge controllers).
*Note: Through further refinements, Sunpower has been able to increase the Wattage on the newer version of these panels to 345 Watts.

#5 Solar  charge controllers

During one run at 11:30 am, with the average battery state of charge at 40% and a heading of 158° True (Summer- Southern Hemisphere), I observed an output of 238.8 amps from the Outback MPPT solar charge controllers.

#6 Clamp meter output (1)

#7 Blue Sea Metr

The panels were pretty clean during our testing.

#8 Clean panels

Where the system was truly impressive though was in its ability to provide 40-60 amps late in the day, or when it was cloudy as shown in the photo below. As a note, the battery SOC was 58% and the voltage without the solar array attached.

#9 Shady output


True to their word, the panels have a very long “solar day”, giving them a huge advantage over others.

Based on my testing, I calculate the boat could realize a gain of 1200-1300 amps per day.

#11 panel edge

One of the design criteria has been to keep the array cool. In 78°-85°F ambient temperatures with the sun directly overhead, the face temperatures ranged from 112-118°F while the underside never exceeded 101°F. We will continue to monitor as the boat gets into warmer climes, since we assume the face temperatures will climb and inhibit the output somewhat.

Posted by admin  (January 26, 2015)

22 Responses to “FPB 97-1 All Charged Up: Solar Report From Mark Fritzer”

  1. Michael Says:

    That is some serious juice! My neighbors home has 20x320w Sunpower panels and he sells the overage to the power company.

    What brand batteries are in the FPB?

  2. Mark Fritzer Says:

    We use Hoppecke OpZV batteries.

  3. Paul Says:

    To me it looks like the traction battery’s have been moved from the original drawings.
    Does that change the layout of the utility room?

  4. Mark Fritzer Says:

    The batteries are basically in the same area, just dropped below sole. Regarding the layout, this has been refined from the preliminary renderings which allow for a larger crew cabin.

  5. Paul Says:

    Thanks Mark
    Are you able to share a drawing of the refined crew area?

  6. Mark Fritzer Says:

    Hi Paul, we don’t post or share drawings as a rule.
    Cheers, Mark

  7. Carl E Says:

    Hi Mark: I wonder if you can comment on the extent to which the FPB 97’s systems room/guest cabin now offers something comparable to FPB 78-2: not just two bunks with a wet head, but also seating (and perhaps more of an ambiance with less high-power electric gear and pumps in plain view :); literally dropping the batteries certainly must have helped). As is, the publicly available plans make the 78 seem the better option for those wanting to attract crew?

  8. Todd Rickard Says:

    Hi Carl. The crew cabin of the 97 turned out a far better space than originally rendered. For privacy reasons, we are unable to share photos. However, the crew cabin is it’s own nicely appointed cabin with ensuite head, separated from the “systems” room, machinery, and hallway. The accommodation deck of the FPB 97 is fairly customizable within the boundaries of structural bulkheads and systems. A crew layout similar to the FPB 78 could be accommodated should the buyer desire.

  9. David Says:

    So, how many amps will the FPB97 consume in a 24 hour period given “average” or typical use? If the sky was dark and the gen turned off how many days of running are we talking assuming perhaps a 50% depth of discharge?

  10. Paul Says:

    No problem on sharing the drawings, to me it sounds like a good refinement, that was the one part of the boat I couldn’t get my head around.
    Is there a shower in the crew area now?
    What a amazing yacht!
    Thanks Paul

  11. mark Says:

    Yes, there is a shower in the wet head with a partition for isolating the shower area from the rest of the head.

  12. Andre Says:


    Why use 24V for the battery bank? Wouldn’t 48V be more efficient? I know that the inverters and the charge controllers are able to do 48v, my guess is that the alternators are 24V as are the DC electronics and you don’t want to use a converter.



  13. Mark Says:

    While 48V would seem to be more efficient, the availability of equipment that will run on that voltage is limited. Therefore, when you consider the inefficiencies of converters, the remote places the boats travel and access to that equipment should it fail, we believe 24V to be the better voltage for our application.
    Cheers, Mark

  14. marco Says:

    I went to Mooloolaba (Queensland, Australia) last week and saw Iceberg parked in the marina over there! Any word on how the maiden trans Tasman passage went?

  15. Steve Dashew Says:

    We are just looking at the VDR data now. Passage went well, no problems reported.

  16. Shannon Says:

    I was wondering, why don’t you use any wind generators? There are obvious drawbacks but seems to me a few medium sized wind generators up top could have some benefits. They would add a trickle charge any time the wind is blowing. Over night when solar isn’t adding to the charge the little windmills could be buying additional hours without having to run generators.
    If power at anchor is the main issue, they wouldn’t even need to rotate 360 degrees if clearance is an issue. Just mount the blades in a solid housing & let the boat swing bow into the wind. Of course that would limit their usefulness. I am picturing something like a 2′ foot high box with 5 or 6 blades mounted in there that runs the width of the boat just under the radar & antenna. Built into the mast structure. Of course that’s more weight up high.
    Anyways, my brain is going 1,000 mph, that’s seldom a good thing. I was just wondering if you had seriously considered any type of wind generators & what benefits / drawbacks there would be.

  17. Steve Dashew Says:

    Hi Shannon:
    We have been looking at wind generators since we first saw a big permanent magnet unit belting out the watts in 1978. There are a couple of drawbacks which have kept us from this route. Noise, vibration, dealing with high winds, and safety issues. Now, with the high efficiency panels that are available wind generators make even less sense to us.

  18. Paul Says:

    Hi, when will you be showing us the pictures of the completed interior of the boat, can’t wait

  19. Robert Says:

    I was wondering if it would be feasible to replace the battery banks with a Tesla Powerwall (http://www.teslamotors.com/powerwall)?

  20. Steve Dashew Says:

    Hi Robert:
    Perhaps some day. But right now all of the high density solutions are a bit on the tempermental side for our needs.

  21. Roger Says:

    Robert, A better choice than Tesla may be saltwater batteries; at least they would be in a familiar environment. They work to 100% depth of discharge and 5000 cycles, and made for solar storage. Depth of discharge without damage is a big deal to longevity. Better yet is they’ve been in production. Price per kW is lower too. Aquion Energy http://www.aquionenergy.com

  22. Steve Dashew Says:

    Thanks for thetip Roger:
    Do you have any experience with this style of battery, or does anyone else?