Repowering with Electric

[Keith]

I was just reading an article in Windcheck (thank you for the link Cathy) on repowering with an electric motor. Although my 37 yer old raw water cooled MD7A is running just fine I know that one day I'll have to bid her a fond good bye. I would like to hear from any other Cape Dorians that have repowered with an electric motor or are thinking of it.

I think that it makes a lot of sense and it is very scaleable. For example I currently mostly day sail so I only use the motor to go in and out of my small harbor. I run the motor for 5-10 minutes while prepping MOON DANCE for a days sail and then motor through the channel for 5 minutes or so. Then the same on my return for a total of less then a half hour per sail. I sail both weekend days and long weekends. So for me I could start with minimal battery storage and minimal charging capabilities as solar or wind would have all week to charge the batteries. When I decide to do some cruising for weekends I can up the battery and charging capacities. If I decide to go long distance cruising the capacities can be increased even more. All of this for less money then a new Beta and train and lets not forget the environmental impact.

Looking forward to some healthy discussion.

Keith

[tjr818]

Keith,
Our situation is much like yours. We mostly daysail and we only have to motor out of and back into the harbor. We always try to motor for at least 20 minutes, just because we understand that it is better for the diesel to get fully warmed each time it runs. We actually only need about two minutes of motoring going out, coming back in if there is a current we might need to motor for five minutes. I am very anxious to make the switch, but our 35 year old YSM8 just keeps on running. I remember the surveyor telling us when we bought Slainte, that there was good news about the YSM8 and bad news. The good news is that it will run forever. The bad news is that it WILL run forever. From what little research I have done I know that you can get by with less horsepower going electric; also a boat uses just as much energy to cruise as it takes during acceleration, unlike a car that will use less power once up to speed. The YSM8 sounds a lot like the African Queen when it is running. It will be very nice to cruise quietly with an electric motor.

[GeorgeH]

Keith - when Spartina's original MD7 gave up the ghost two years ago I looked into repowering with an electric engine but there wasn't a whole lot information and the reviews I did find seemed to indicate that electric engines had short cruising times because of battery technology Then. I think there has been much improvement since with more companies offering electric engine options and better batteries.

I opted for a rebuilt Yanmar but would probably choose an electric engine today. There is a letter in this month's WindCheck Magazine about further developments in electric engine repowering.

http://www.windcheckmagazine.com/letter ... _takes_you

[Keith]

Hi George,

It was that article in Windcheck that got me interested. He claims that you can have infinite range cruising with prop regeneration while sailing, solar and wind turbine. As I describe earlier not what I need now but great to the the option of scaling up in the future. Not to mention that battery and solar panel technology is increasing every year.

Thanks for your comments,

Keith

PS still look to see if an CD owners have gone electric. If not, who will be first???

[tjr818]

Another benefit to going electric is winterizing. Here in the midwest we usually winterize the engine around Thanksgiving; as soon as we do along comes a nice warm spell and we can't go out without having to re-winterize. So many times this has happened that I have ween long for the days when I sailed a boat with an outboard engine. Back then all we had to do was tilt the outboard up an out of the water, turn it to one side and all the water would drain out, ready to go sailing again on the first warm day that came along, often that would be close to Christmas. The only thing that would bring sailing to a halt would be a frozen harbor, When that happened we knew sailing was over for the winter, the outboard would be brought home and winterized in the garage. All electric would be ready to go anytime up until the harbor froze over.

[Jeff and Sarah]

I would LOVE to switch to electric but my engine continues to run (and I'm quite fine with that). My biggest reason for considering electric is not having to winterize the engine (though my engine compartment heater lets me do that now with the diesel, granted with some risk). My biggest concern with it is the battery bank. The effects of cold temperatures on batteries somewhat reduces the advantages of electric power for winter boating. Once lithium-ion technology gets another couple years down the road it will be pretty tempting. For now the cost of those batteries is so astronomically high it would be a hard bullet to swallow. Of course more traditional battery types would work, but the attributes of lithium ion are more interesting to me.

I've never been convinced with prop-regeneration. I think it is unlikely you'd gain much back with the typical hull configuration of a Cape Dory. I'd also guess that much of the numbers people calculate are based on sailing at hull speed which is a relatively small percentage of time in reality.

Every time I start researching this conversion I'm reminded a brand new diesel would be a pretty nice upgrade too.

[Maine_Buzzard]

Perhaps the best way I can say it is that new boats, built around a Lithium Ion battery pack and electric drive will be a great thing.

Converting existing CD boats, not so great. Too many issues with locating the battery pack of sufficient KWHr capacity and adapting the prop opening to power better with a folding/feathering prop suited for electric motor usage. You would need a reduction system for the prop, and a more slippery hull than Carl's to make the $15K investment in E drive pay off.

I love the idea, but the boat needs to be designed to the concept.

[Keith]

Hey Maine,

I wouldn't give up so easily. Captineer is working on an Alden 30. So it will be interesting to see what type of performance they get from her. Their base installed system for a CD 30 would cost $7950/$8250 for the 10KW/12.5KW respectively. Both say that they would work for a 30 footer. So kinda like deciding on a Beta 16 or 20. This does not include the charging system just motor, motor controls and battery bank. Not sure about shaft, prop, etc... I have sent them an inquiry to find out exactly what it does include and if they sell it as a DIY kit and for how much if they do. So lots of questions but again I'm not giving up on it so easily and as I stated in the original thread the MD7A is still purring along quite nicely. OK not exactly purring more like chugging!

Also I haven't checked into any other supplier of electric propulsion systems. I'll keep everyone updated as I find out more. Still looking to see if any CDers have actually converted.

Keith

[moctrams]

A guy in our harbor removed the old engine in his 30’ wooden Cheoy Lee ketch and installed an electric motor drive system. He has solar panels to keep the batteries charged and even sailed to Philadelphia to work on a solar wind project and lived on the boat for several months. I don’t know how or what he uses for batteries, but he says the five year old system works very well.

[Maine Sail]

First you need to honestly define your "box". Are you really an in/out of the marina user or will you honestly really want to wander further afield?

E-conversions can work well for the in/out of the marina user but often fail to deliver the desired outcomes beyond that..

The only thing I can say to help you is to keep everyone around you honest:

Trust Ohm's Law - Many e-boat re-sellers try to re-wire it, but as of yet no one has been successful.. For example...

Convert Watts to Amps at fixed voltage:

Watts ÷ Volts = Amps

eg:
5000W ÷ 12V = 417A
5000W ÷ 48V = 104A


Never Forget Peukert - When dealing with high load applications, such as e-boats, one simply can not ignore Peukert's Law when dealing with lead acid batteries..

A 100Ah lead acid battery is only a 100Ah battery when used at, and discharged at 5A at 77F-80F, when new or just broken in.

Every other load & temp range either above or below the 20 hour rate at 77-80F results in CHANGES the batteries 20 hour rated Ah capacity. Cycle life and DOD also impact Ah capacity.. Anyone telling you otherwise is really not qualified to be doing so. If an e-boat re-seller has not accounted for Peukert they have not done their job.

Also in colder climates with cold water or early or late in the season you can literally cut your capacity by 1/3 or more due to battery temps.. Batteries are rated at 77-80F and at 50F, or colder, can not put up the same Ah capacity. This means your usable range changes based on physical battery temp.

The typical AGM's being used can only claim about 400 cycles to 80% DOD but that IS IN A LABORATORY. Real world, not lab derived under carefully controlled conditions, will rarely break 200 cycles for lead acid and this is at 50% DOD use. Most e-boat sellers are sizing the projected range at 80% DOD and ignoring Peukert.......

LiFePO4 cells have minimal Peukert's corrections but they are still not a Peukert of 1.0. A 100Ah battery with a 1.0 Peukert would deliver 100Ah under a 300A load and conversely the same 100Ah battery would provide 100Ah under a 0.5A load. A Peukert 1.0 battery simply does not exist for the marine market even with LiFePO4... The reality is that a LiFePO4is still slightly affected by Peukert but totally unaffected by sulfation which is what murders lead acid.

Peukert with a flooded lead acid 100Ah battery:

100Ah Battery 300A Load = 33 Ah
100Ah Battery 0.5A Load = 140+ Ah's

Multiple on-board battery banks:

In most situations you will now also have two battery systems, house & e-motor at two different voltages but no large current source that can be directed at either unless tied to the dock. Some e-boat guys will try and steer you towards "tapping into" the propulsion bank with a 48V to 12V etc. converter but this can create problems with series balance, and if you have a windlass the converter will not last long with the high in-rush demands. These are the things they don't always tell you..

When we discuss battery weight we should always be cognizant of the fact that you will usually still need a 12V house bank. A typical 225Ah 48V propulsion bank may weigh 520 pounds but then the house bank may be another 130 or so pounds making for approx 650 pounds of batteries on a 30 foot boat.

If you day sail only, and are energy conscious, you could get away with a single 65 pound house bank but most 30 footers I set foot on already use more than one house battery. With now approx 600 pounds of battery on a 30 footer placement for weight distribution becomes important.

With diesels we also have fuel capacity weight, which is also not very light-weight. A 20 gallon tank when full would weigh about 140 pounds +/-.. So a small 175 pound diesel engine + 140 fuel = 315 pounds.

Lots of e-boats use golf cart batteries and for the typical 48V bank this makes an 8 cell GC2 bank about 200 pounds heavier not including the weight of the electric motor and gear which can be 100 pounds +/- with wire mounts, motor, motor controller etc...... So on a CD-30 it is conceivable the the electric motor conversion could potentially add about 300 +/- pounds over the current diesel engine to the boat. If properly placed this is not a huge deal but make sure you are getting honest assessments and honest numbers.

On a 30 footer I don't know that you could fit enough solar or wind to charge two banks adequately in the time frame you would want, especially if you were to head off cruising. Regen will not keep up but when paired with solar and wind it can certainly help. To keep everything honest you now add the cost of solar, controllers, mounts and wind gen + pole plus controller to the conversion figure......

E-power is usually the best fit for boats that are tied to a dock when done sailing or you wait significant time between uses to recharge via solar & wind. Some will use a Honda generator to make 2 +/- knots when they need extended range but to me this entirely defeats the purpose of e-power and I find a Honda EU2000 quite lound, compared to a diesel in-board, when used on deck at full bore running the e-boat in "hybrid" mode.

By the time one gets done building a system like this a rebuild of a diesel is not all that expensive..

This is not to say e-power can't be done, it can be done very suitably if your use fits into the box.. Unfortunately "e" currently fits into a pretty tight box, range wise, for e only power. To do these systems right can be very expensive and then you still need to replace expensive banks every few years... The e conversion is only part of the expense if you also want wind and solar, and don't even think about the sub 1.5k wind gens as they really don't perform.

One also has to consider the cost of batteries over the life of the boat. AGM's, due to low Peukert, are better served for an e-boat, LiFePO4 being best, but AGM's can run $300.00 to $800.00 per battery depending upon the bank Ah capacity you desire. If you chew through a bank in a few years this gets expensive. If you shallow-cycle, recharge to 100% SOC as often as you humanly can, and make them last 5-7 years, they become less expensive. Still it is a $2000.00 + hit when you need to replace them..

Please do all the math, run all the figures and keep the e-boat re-sellers honest. I have run the numbers for numerous customers who've been quoted and have yet to find any of them that have been what I would consider "honest" or telling the "whole truth".

I did a consult for a guy two years ago who was told he could do 45-50nm at "about 4 knots". He was quite angry that the "projected numbers" were not lining up with the voltages he was seeing. His battery voltage often sagging to less than 8V, which spells a quick death for lead acid batteries.

He had a 260Ah bank at 48V with a Peukert of 1.27. A Fluke clamp on meter showed he was burning 62A to do just 3.6 knots in pretty flat water with just a bit of slime on the bottom paint. Simple math, including Peukert, using a 100% DOD figure showed that with a 100% discharge at 3.6 knots he could go about 9.9nm until his bank was at 0% SOC, under 8nm at 80% DOD and under 5nm at 50% DOD. Needless to say he was not happy about the projections he was lead to believe were true. You MUST educate yourself if you want any sort of accuracy in your projections. Ohm's law, Peukert, battery & temperature, with lead acid batteries, can not be forgotten about.

E-conversions can definitely work if you run the numbers correctly and are honest with yourself about your desired use...

[Sea Hunt Video]

I remember the surveyor telling us when we bought Slainte, that there was good news about the YSM8 and bad news. The good news is that it will run forever. The bad news is that it WILL run forever.

Tim and all:

Fortunately, that is my problem as well. The two (2) prior caretakers of S/V Bali Ha'i took VERY good care of the Yanmar 1GM. When the day comes that the Yanmar 1GM has to be replaced I will replace with a similar engine - only a little more hp.

I assume that electrical power can work well on some sailboats, as stated by Maine Sail. For me, I prefer a diesel engine for the simple reason that I can actually "see" the fuel, touch the injectors, look at the oil color, etc. With electrical power, the lack of a "touchy feely" system (you cannot see electrons - at least I can't ) is probably a part of why I have a lot of difficulty dealing with electrical issues. Having an electric engine would only add to my difficulties. DIESEL POWER

[Paul D.]

These guys are doing an interesting electric conversion using a forklift motor. The boat is a Pearson 36.

https://youtu.be/_L1xmG5Kndw

I think Maine Sail is correct in being sure to double check the numbers and expect less actual performance. But if you are truly using the motor only for short durations and have ample charge times, it may be a good option.

[Steve Laume]

Resale would also be a consideration in going to E-power. While you might be comfortable with this propulsion system for the sailing situation you are currently in, it would not work for the vast majority of boat owners. That would severely limit potential buyers, Steve.

[tjr818]

True, but it may also entice some others.
Perhaps

[jepomer]

I have been using electric power for my Capri 22 that sits on a mooring all summer. As Maine Sail said, You have to know how you are going to use the boat.

In my case, I primarily daysail. Other motoring in or out of the mooring field, I do run close to full throttle to get to the start lines in the greater Boston Harbor area — because we are always running late and the wind is blowing in the wrong directions. I've been 12 nautical miles out and motored back at 2-3 knots AFTER motoring out to the start line.

The batteries are charged using 110 watt Ganz Flexible panel array mounted on the foredeck. I can walk on these panels as needed. The battery bank consists of four GC2 6-volt batteries in series to provide the 24 VDC needed for the Torqeedo Cruise 2.0 electric outboard. I use two separate Genasun MPPT charge controllers — one 24 volt one that takes the panel array's nominal 12 vdc to make the proper charging profile for the 24 vdc motive bank. A separate charge controller maintains the "house" 12 vdc battery for lights, radio, and navigation.

Although I do have a Promariner 3 channel charger, I have not needed to use it on the water. I do use it to maintain the batteries when the boat is covered in the driveway.

For my purposes, an electric motor and associated charging systems fit my needs as a day sailor.