Hello and question re Electric Conversion

[Joe]

Greetings from New England. I have a 2003 Horizon inboard, the Mia Dale, which lives proudly but modestly on Nantucket among some of the most beautiful catboats around, still a very nice sailing boat and well cared for by me. I'm thinking of jumping down the rabbit hole of an electric inboard repower and wondering if anyone can share any experiences.

Here's my story - my main needs are for trolling in and out of the inner harbor and the occasional trip as far as the Cape, about 34 NM from our location in the inner harbor. Generally I'm motoring for now more than 30-60 min per trip, once a week, and in favorable conditions, occasionally going against current. I'd probably only be willing to do this if it could be a truly electric - no inboard, no generator, no hybrid, as it doesn't make sense to me to do this if I am still tinkering with fuel and combustion engines of any kind.  I'm looking specifically at the Elco line of inboards. The only glitch, as is common when contemplating these conversions, is how to keep the battery topped off via solar and wind while moored. I'm not interested in tattooing the boat with solar panels and windmills, and am really trying to find someone who has attempted this before. I'd be willing to lay a panel on top of the sliding companionway, and also on the foredeck, even over the hatch, and perhaps manually lay one or two more panels down in the cockpit while moored, and maybe add a wind generator if it could be done in a cosmetically appealing way. Having trouble figuring out how efficient this would be a keeping the 48V battery array topped off. Specifically, can I run the batteries down one week, and come back next week to a full charge, assuming average sunlight.

Any feedback would be helpful.

Warmly,
Joe

[rbh1515]

If you scroll down a bit on the Horizon section you will see this HC that is electric powered.  I think they built it this way at the factory.  Its currently for sale, but I bet the owner could give you a bunch of info.  Or you could sell yours (there seems to be a lot of interest in used HC's without many on the market) and buy his which to me looks like a very nice price for a newer boat.
http://cpyoa.geekworkshosting.com/forum/index.php?topic=11120.0
Rob

[Joe]

Yes, thank you, I am familiar with this boat. The boat itself would not work for me, but the build is interesting. I know I can do the Elco swap easily, just concerned over charging without power. I did email the seller. Thanks again.

[cdflan]

Hi Joe
If I remember your email correctly, you wanted wheel steering and were concerned about access for charging.

In answer to your separate message, I keep the batteries topped off using a ProMariner 360 Quad charger which has four separate outputs and keeps the array equalized.  Obviously, without shore power this won't work for you.

The 4 Odyssey batteries I have are rated at 200AH and the Torqeedo at 4KW.  Based on the tests I've run, 35NM would be about the limit on a full charge.  I've done 35NM cruises but motor sailing in light air and not solely on battery power.

Assuming an Elco or Mastervolt drive on your existing shaft/prop is as efficient as the Torqeedo and that you have a week of sun to recharge, four separate solar panels about 2' x 4' should provide enough recharge power after your 34NM trip.  I'm not familiar with the charge controllers for solar panels but the question you would need to pursue is whether they provide desulfanation pulses after getting to float voltage given the slower recharge from a solar system.

After having electric auxiliary power for the last 4 or 5 years, I would never go back to gas or diesel!

[Joe]

cdflan this is extraordinarily useful information. I just can't envision ever venturing out in such still air that I'd actually be motoring for over 34 miles in a single trip. I'm going to keep exploring the concept for viability. I would very much like to experience propulsion without the upkeep, noise, heat, smell, vibration, and pollution of diesel. The small Minn-Kota trolling motor I picked up for my tender is such a pleasure, it's hard not to imagine electric propulsion on a larger scale. And yes, my Horizon has wheel steering. Before I settled on the Horizon i was looking at an M-18 with tiller and wondering about a retrofit. I do prefer the wheel, so your specific set up would probably not make sense on my boat. This whole enterprise is not cheap, and in the end, if range/charge anxiety doesn't do the project in, it could be the cost.

[wes]

Joe - I'll be following your plans with great interest. Like you, the sooner I can get rid of fossil fuel the better.

Since you are venturing into very large and expensive battery banks, highly recommend you spend an evening reading the battery related articles on RC Collins' excellent blog site:

www.marinehowto.com

He is adamant that maximizing the life and performance of your expensive batteries depends on a smart charger capable of being tweaked for the exact charging voltages designed by the battery manufacturer and having proper temperature compensation. He offers a wealth of knowledge and has a clear, direct writing style.

Wes

[Joe]

I think the common ways most of us enjoy our little to medium sized boats really lends itself to being vanguards for the movement away from fossil fuels. Battery technology still makes speed/motorboats decades away from being reasonable conversion candidates, except for maybe harbor launches, and the larger cruising sailboats have a good deal more complexity in order to totally be free of fossil fuels (hybrids, sail drives, diesels, generators - no thanks!) and, to me, you run the risk of just substituting one headache for another. On the other end of the spectrum, the tiny sailboats generally do not motor as much as we do, so a simple outboard, electric or gas, is probably just fine. In our world, the inboard diesels are generally relied upon more to maneuver through channels, etc., but still not used for very long periods, as we all tend to want to be under wind power and often won't go out at all in still air, especially on a longer cruise, plus the small size of our cabins (in general) leads most of us to cruise for relatively short distances and periods of times, obviously with some exceptions. So for us, the range limitations of electric are not really an issue, particularly if shore power is available.

[cdflan]

Wes/Joe
Agree on the battery charger which is why I went with the ProMariner.  It comes with charge voltage adjustment for the specific battery manufacturer you're using, keeps the bank equalized, pulses periodically to avoid lead sulfate buildup.  Haven't run a capacity test recently but open circuit and discharge curve voltage says they're close to rated capacity.
Getting the equivalent controller for a solar array would be my concern as noted above.  Haven't researched solar controllers so can't advise on that.

[wes]

I'm a CP 27 coastal sailor in North Carolina. Sometimes day sailing on rivers and sounds, sometimes transiting sections of the ICW for weekend cruises. Joe, I mostly agree with your comments, certainly that for day sailing the electric solution seems more than adequate.

However on longer trips I've found myself motoring 35 nm in a single day, for example in the ICW where the channel is too sheltered to sail, or when the wind is dead foul and I need to get to the next anchorage or marina by nightfall. I think a 35 nm max range is workable for me, but just barely. I'd be more comfortable with 50 nm but wouldn't want to pay a steep penalty in weight or cost to get it.

If I get serious about this I'll probably call Elco and discuss the EP-12 vs EP-20. The EP-12 appears similar to my Universal M-12 diesel, which many CP 27 owners consider underpowered (Hutchins changed to an 18 hp diesel in later production years, which would match up closer to the EP-20). But I suspect electric is not directly comparable to diesel and the Elco guys probably have some thoughts about this.

It's an expensive conversion, although repowering with diesel isn't cheap either.

Wes

[Joe]

I tried calling Elco today to run a few things by them but didn't get through. I'm thinking for a Horizon we'd be looking at a 6 or 12. Can't quite tell from their spec sheets which would allow for more mileage for a given battery stack, seems like the 6 is probably fine. Wondering how much of a weight issue we're dealing with at between 150 - 250 lbs for the engine plus whatever the batteries weigh, considering we're losing the diesel and 23 gallons of fuel, and possibly some ballast from the keel if need be. Agree though, adding a second back-up stack of batteries would be very costly, heavy, take of space, and add more complexity to the wiring scheme, and as well as maintenance. Simplification is key for me on this. Don't want to replace one issue with another, and be out a wad of money in doing so.

[cdflan]

Just to complete the planning when I electrified my Horizon Cat, for long range cruising I had anticipated putting a folding platform on the transom to hold a small generator and reserve fuel. I had looked at the Honda 2000 (more recently, there is an equivalent Predator at half the price) which adequately supplies the 1000 watts or so required by the ProMariner charger.

[Joe]

Thanks. I was wondering if I could just keep some fuel in my main tank if needed and keep a back up generator stowed below deck. I'd probably start with the bare minimum and then build out from there. My gut tells me that for most of my sailing my charge is never really going to drop below 50%.

[moonlight]

Start with a reliable and trusted supplier.

In full disclosure mode, I've been a dealer for multiple lines partnered with Annapolis Hybrid Marine for almost a decade?  I've also been and/or remain a dealer for Torqeedo, Elco, Mastervolt, Electric Yacht, and more.  There is a lot of change in this market; all these others change between dealer networks and factory direct every few years leading to a lot of hassle, inconsistency, and confusion.

The baseline average we use down here on the Gulf Coast is universally a minimum 200 amp hour battery bank.  I lean heavily to lithium batteries, Annapolis Hybrid is still uncomfortable in that regard and leans towards thin plate pure lead.

Back to basics:
200Ax48V=9600W
÷5 days = 2000W
÷5 hrs = 400W

So there's your minimum solar array.... pretty huge for a Horizon Cat; and we haven't further derated because it sounds like you're on a mooring with attendant difficulty maintaining sun angle.

We use these common denominators for a reason. Might you get more (daylight, etc)?  Maybe.  But if you don't follow industry norms, you wind up dissatisfied, and some people then try to cast the black eye on the industry, not their faulty calculations...

PM me for actual cruise/range/depth of discharge calculations; or email info@moonlightmarine.com

And keep fuel in your main tank?  I've already removed that tank for batteries or other gear. That fuel would be crap before you ever got around to using it.  A 3-gallon portable, fresh, if you ever have to go hybrid.

I suspect a wind generator is your answer... not solar.

[Joe]

Email heading your way shortly, Moonlight. Thanks for your input and interest.