Switched to Electric

[Phil]

I recently had the original Volvo MD7A removed from my 1981 Morris Annie and replaced with an ElectricYachts Quiet Torque 10 Electric Motor. The new motor is powered by 12 Battle Born 12V, 100 Ahr batteries wired in series / parallel to result in a 48V, 300 Ahr system. Battery charging is done via 120V shore power, motor regeneration while under sail, and soon to be added solar panels.

I kept the two previous batteries (1 house & 1 starter), Optima, 12V, 50 Ahr, AGMs. Each is charged by a dedicated 50W solar panel and Victron MPPT charge controller. These solar panels are mounted on the stern rail. The 12V system is currently isolated from the 48V system. I may add a DC-DC converter down the road, but don't see any reason to do so at this point.

I got a quote to get a new Volvo D1-20 before making my final decision. Total price for the Volvo installed was about the same total cost as going electric +/- $1000. Going electric came in at ~$22K. I did have some additional work done by the shipwright (new cabin heater, sanitation hoses, and stuff that got discovered as "needed to be fixed" as we pulled things apart).

Since people will want to know these details here weights. It's not everything, but the rest of the stuff is pretty much a wash with the exception of the old transmission we pulled out. That thing was a pig.
Total weight of the MD7A (motor, tank, fuel) = 516 lbs
Total weight of D1-20 (motor, tank, fuel) = 436 lbs
Total weight of QT10 (motor, batteries, charger) = 452 lbs

All of the work was done at the Berkeley Marine Center by Sean Shigley of Shigley Shipwrights. He's done a ton of these swaps to electric and really knows his stuff. Great guy to work with and very reasonably priced.

Here are some photos:
Old motor - loud, vibrates a lot, and smells like Mordor. Also was getting really flakey.

New engine compartment

Bus bars and 3 batteries.

Cabin sole battery bank. These sit where the old fuel tank used to sit. The 3rd battery bank is on a shelf behind the motor & below the cockpit sole. The shelf was already there and the previous owner had installed ~150 lbs of lead ballast for some reason. Chuck Paine has no knowledge of why that was done.

Shore power charge controller. Not show, but there is plenty of room for a solar panel boost MPPT charge controller on this surface.

Power control panels. 48V motor on/off is the red dial at the top left. Shore power charing on/off is the breaker on the far right.

House batteries, Victron MPPT charge controllers, and 15A breakers beneath the quarter berth.

Motor throttle located in the same spot as the old one. The motor display is also located in the same spot as the old one, but I just included a very low res factory photo because I forgot to shoot one. The display is actually quite good and easy to read.

 

[dlochner]

Nice! Do you have an idea of the performance, such as how long/far you can run on one charge? How much power can be restored through regeneration?

 

[jon hansen]

very cool.

 

[Phil]

Nice! Do you have an idea of the performance, such as how long/far you can run on one charge? How much power can be restored through regeneration?

I have the engineer's estimates which I've already found to be extremely conservative. Range depends on how fast your are motoring. 2kts gets you 100nm and 4kts gets you 22nm based on his calculations. He did admit that he uses a very healthy margin of safety in those numbers and from the few tests I've done I agree. I'm estimating I could do 1.5 to 2.0 times those ranges at the given speeds. I haven't had time to play with the regen feature yet. Wind has been very light recently. I'll post info on that feature when I get time to test it out.

Yeah...I know these ranges might seem short to many, but I'm the kind of sailor who rarely uses the motor. I use it to get in and out of the marina.My daughter and I did motor sail from Berkeley to Redwood City because the winds were light. Ran the motor between 800 and 1200 rpm depending on the wind for the ~24.5nm trip. Boat speed was always between 4.6kt and 6.5kts per GPS with the boost of the incoming tide. Final battery state of charge was ~55%.

Obvious ways to extend range: ~300W of solar panels that will easily fit on my boat, regen while sailing, suitcase generator (I won't be going this route).

 

[jviss]

Interesting, but note that regeneration is going to significantly slow you down! Sailors are concerned about the prop spinning even when it's not driving a generator!

 

[Phil]

Interesting, but note that regeneration is going to significantly slow you down! Sailors are concerned about the prop spinning even when it's not driving a generator!

Yes, I realize that it will slow me down in regen mode. I did manage to do my homework before spending > $20K.

 

[Tom J]

Very nice! This will be the perfect setup for your trip to Hawaii, especially with the 300w of solar panels.

 

[jviss]

I find it interesting - fascinating - how people can justify decisions with some kind of logic; I don't know what to call it, I'm sure there's a term for it. But the idea that slowing a sailboat with an in-water generator, in order to charge a battery that's used for propulsion, is kinda crazy, in my opinion. First, you'd have to sail across he ocean for it to charge worth a darn, don't you think? And meanwhile everywhere you go, you're going maybe 20%, even 30% slower. And, I don't imagine most boats have a prop optimized for this purpose. I honestly don't know the numbers, but my intuition is that it's not a very efficient trade off. I'm happy to be convinced otherwise, but I think it's hard to beat a diesel with a big alternator on it for coastal cruising. Oh, and by the way, I'm on a mooring. Sure, over the work week a couple of 120 Watt solar panels will charge up the batts. But come the weekend, running the fridge and also propulsion - not so sure. I'd like to hear the numbers on that.

 

[Brian D]

JVISS, obviously the OP is not overly concerned with the consequences of his rotating prop slowing him down. Where does he have to go in a hurry? I thought sailing was about the adventure, not getting to a destination by a certain time. Maybe I was wrong.

I like the idea of using solar panels to keep batteries topped, as much as possible. But isn't that considered adding additional weight to the boat? Or even wind generators adding added wind resistance would "slow one down". It is all good.

So personally I hope we can keep this civil. Again, I am personally interested in the electric concept as a means of weight savings in the engine and fuel. But, I guess until we get lunar panels, we are kind of the mercy of the night sky. LOL

 

[dirt rd]

Nice installation. Thanks for the detailed report. The plan is to sail.

 

[jviss]

Yea, I'm sorry for the snide remarks. I didn't really mean to be mean.

Electric is great - it's what has powered submarines for over a century. It's fine if you're at a dock and can plug in. But there's no way, according to my engineer-intuition, that regeneration with the prop or even solar, is going to make a dent in a propulsion bank. Prove me wrong, please! But I can't even put enough solar on my bimini to power the fridge 24/7. I'm at a mooring, so solar is a great solution for topping off the batteries at the end of the weekend. But I've done the math, and I had about 220W of panels on my previous boat, and given the amount of daylight, and changing angle of the sun to the array, it just wasn't enough to keep up with a 5A, 50% duty cycle load.

I could really go for a hybrid, as Vetus was once marketing, to have a super efficient, low RPM diesel generator charging the propulsion bank as needed, and when convenient, but have the instant, high-torque power of an electric drive.

Good luck! It looks like a really clean installation.

 

[smokey73]

@Phil Interesting conversion. So much of the decision process for a conversion like this ultimately depends on the local sailing conditions and intended "use" of the boat and to some extent "perceptions" and personal preference. I"d be interested in a breakdown of the decision process that was used that leaned you towards the electric conversion. It looks like it wasn't cost or weight since it looks like these were about a wash. It would be a pretty long discussion so an attachment (spreadsheet, white paper, etc) would probably be better than a two page post. I'm assuming you have all this written down some place and would not ask you to create something you haven't already created. (My boat is in the yard for a rudder rebuild so I obviously have too much time on my hands )

I'm not considring an electric conversion but as an Ngineer I'm always interested in the cost/benefit analysis of an engineering decision. I don't think it would work where I primarily sail because of sailing conditions and my intended use.

 

[smokey73]

@Phil After your trip motoring for 24.5nm, how long did it take to recharge from a 45% state of discharge to 100% charged and were you able to do that at a 30A shore source or did you have to use a 50A shore power source? Someday, marinas may very well have "rapid charge" stations like they have for Tesla's at a limited number of hotels. Even saw one near a Cracker Barrel one time (don't remember where though)

 

[dLj]

@jviss I don't know what the OP is doing here for regeneration while sailing, but Watt & Sea build a dedicated unit that is highly regarded. I've been told this technology can run everything electric on my current boat while cruising - easily.

Hydrogenerators - Watt and Sea

Hydrogenerators - A good management of the energy on board is the key point to sail in total serenity, regardless the consumption of the on-board.

www.wattandsea.com

dj

 

[jviss]

@Phil After your trip motoring for 24.5nm, how long did it take to recharge from a 45% state of discharge to 100% charged and were you able to do that at a 30A shore source or did you have to use a 50A shore power source? Someday, marinas may very well have "rapid charge" stations like they have for Tesla's at a limited number of hotels. Even saw one near a Cracker Barrel one time (don't remember where though)

With Lithium-Ion you would normally not charge them beyond 80%, for longer life and faster charging. The last 20% takes a long time, and LION don't last as long if left at 100%.

My guess, considering charging efficiency, is that bank would take 8 hours on a 30A supply to go from 45% to 80%. But that's honestly just a guess. I don't know how "smart" the charger is, and how much of the approx. 5kW available from a 30A shore power outlet is being consumed by other things, like charging the other batts, fridge, etc.

 

[jviss]

@jviss I don't know what the OP is doing here for regeneration while sailing, but Watt & Sea build a dedicated unit that is highly regarded. I've been told this technology can run everything electric on my current boat while cruising - easily.

Hydrogenerators - Watt and Sea

Hydrogenerators - A good management of the energy on board is the key point to sail in total serenity, regardless the consumption of the on-board.

www.wattandsea.com

dj

The power has to come from somewhere, no magic involved, and no such thing as a perpetual motion machine. Even at 100% efficiency for every component of the system, all of the propulsive power used would have to be taken away when regenerating. Reality is worse.

A thought experiment: Assuming 100% efficiency for every component of the system, if you drive the boat with the propulsion system for one hour at 5 kt., and your regeneration system knocks a knot off your speed when sailing, you'd have to sail at 5 kt for 5 hours to put the energy back into the bank. Now start increasing the hours of sailing to make up for the less than 100% efficiency of the propulsion system and charging system.

 

[MikeHoncho]

That was the hull speed with the combustion engine? 4 knots I guess would be somewhat ok if you were on a lake without currents but anywhere in my neck of the woods it would take forever. I wouldn’t even consider 2 knots no matter where you are.
What is the expectation of the over all battery life and what happens if they get imerged in salt water as in if the bilge fills up from a issue?

 

[jon hansen]

sailboats and aux sailboats are two totally different animals. phil has a great, blue water sailboat. most of you don't. you have motorsailers. sailing from A to B is not in your playbook. you run your engine more than you sail when you go A to B. yeah, we see you and it's all good.

some boats are campers, some are condos. hiking a trail is so different than driving an RV to a campground.

phil is like a backpacker, most of yawl ain't. no need to compare the two. two different skill sets.

 

[Phil]

@Phil

I'm not considring an electric conversion but as an Ngineer I'm always interested in the cost/benefit analysis of an engineering decision. I don't think it would work where I primarily sail because of sailing conditions and my intended use.

smokey73 - as you noted the cost & weight trade was a wash. That leaves other benefits & liabilities. The biggest factors there are reliability, maintenance, quality of life while motoring, and environmental impact. Electric wins out on all of those fronts. I'm also an engineer and have been dealing with Li-ion batteries and solar panels for years on spacecraft. Motor maintenance is "grease two zerks once per year and check the motor mount fasteners after the 1st 10 hrs of use and then once per year".

 

[Phil]

@Phil After your trip motoring for 24.5nm, how long did it take to recharge from a 45% state of discharge to 100% charged and were you able to do that at a 30A shore source or did you have to use a 50A shore power source? Someday, marinas may very well have "rapid charge" stations like they have for Tesla's at a limited number of hotels. Even saw one near a Cracker Barrel one time (don't remember where though)

After motoring around with the shipwright the day Kolibri went back in the battery state of charge was ~85%. It was back up to 100% in less than 2 hrs. After the 24.5nm trip I charged it back up to ~85% state of charge because I was heading out of town for a week. That took about 3.5 hours. Both times I used the 30A shore power source.