Saturday, April 30, 2011

[Electric Boats] Re: Just starting, ready for electric motor

 

Hi Jack,

There are a number of reputable vendors that sell complete systems, and I think that most of them have something that would fit your boat. I suggest that you contact: Advanced Marine, Propulsion Marine, Electric Yacht, Annapolis Hybrid Marine or others that you may hear of in this group.

I believe that each person needs to get a feel for how the vendors respond and pick the one that fits his or her specific needs from a price, personality and logistics point of view.

I think that most of the people here have said that their purchase of an electric drive felt like a partnership, I know that my conversion felt like that. These vendors know that each conversion can generate a lot of questions and will typically help you work through the tough parts of your conversion.

For me, the choice to go electric and then the choice of vendors was not something that I rushed into. Through this group, I have gotten to know each of these dealers at some level. However, with my limited experience of converting just my own boat, I don't feel qualified to say that any one of these vendors is better or worse than the others. I do know that I am very pleased with the system and support that I received from Propulsion Marine.

Fair winds,
Eric
1964 Cheoy Lee Bermuda 30 ketch
5.5kW Propulsion Marine drive, 8kWh Lithium batteries
Marina del Rey, CA

--- In electricboats@yahoogroups.com, merit131 <no_reply@...> wrote:
>
> Thanks Eric: That ac-09 sounds like it may be a bit much, I'm not really looking to reinvent the wheel here. I was hoping by coming on this site that others with my same size boat already installed an electric motor and could suggest a motor that would work in my boat. Eric can you suggest a motor that you think would work? or is this a first on this site for this size boat, and I should get looking for the right dealer and the right motor and hope they are being upfront with me regarding their power? Please let me know what you think would work. Thanks Jack
>

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Friday, April 29, 2011

[Electric Boats] Re: How do you measure how much battery life is left whlile you are out sailing?

 

Yup, I don't disagree Tom. They are nice to have.
The method I suggested could be used as an alternative approach for those who don't have an electronic monitor or who want a backup method. Like having a dip-stick to back up your gas gauge.
Cheers,
Jim

--- In electricboats@yahoogroups.com, "Tom" <boat_works@...> wrote:
>
>
>
> Perhaps the accuracy, convenience, and additional features of a battery monitor would be well worth the cost.
>
> I spent about $300 for my LinkPro with a 48V prescaler. It was a small percentage of the cost of my EP system.
>
> I used 30.3 Ah on today's run.
>
> -Tom
>

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[Electric Boats] Re: Just starting, ready for electric motor

 

Thanks Eric: That ac-09 sounds like it may be a bit much, I'm not really looking to reinvent the wheel here. I was hoping by coming on this site that others with my same size boat already installed an electric motor and could suggest a motor that would work in my boat. Eric can you suggest a motor that you think would work? or is this a first on this site for this size boat, and I should get looking for the right dealer and the right motor and hope they are being upfront with me regarding their power? Please let me know what you think would work. Thanks Jack

--- In electricboats@yahoogroups.com, "Eric" <ewdysar@...> wrote:
>
> Well Jack,
>
> First, the "Sevcon Brushless Sailboat Kit - 8.5KW" is an AC motor, at least the Sevcon Gen 4 controller is an AC controller.
>
> The AC-09 system as spec'ed looks like it would work, though I've never heard of anyone running one of those systems in a boat. That drive seems better suited for a motorcycle or a light car. A 350A x 48V system works out to almost 17kW, and even the output of 18hp is 13.5kW (which works out to 80% efficiency). Going back to your boat's requirement of 7kW, this motor looks like it may be twice the power that you need. The good side of this is that your system will never be close to overloaded during normal operation. The bad side is having to build your system to handle 350A, the cables, fuses and batteries will need to be pretty stout (heavy and expensive). It is my personal guideline that the battery should have a usable capacity that can sustain at least 1 hour at max throttle. By that standard, this system would need 1000Ah x 48V of flooded batteries (2100 lbs), 640Ah of AGM batteries (1600 lbs), or 480Ah of Lithium batteries (600 lbs).
>
> You may not need that much electricity storage for normal usage, but you don't want to be blowing fuses, melting cables or damaging your batteries if you apply full throttle.
>
> Perhaps you can make it work. If you do go this route, report back here because you will be exploring options that haven't been covered here before.
>
> Good luck and fair winds,
> Eric
> Marina del Rey, CA
>
>
> --- In electricboats@yahoogroups.com, merit131 <no_reply@> wrote:
> >
> > Thank you Eric for your help. I spoke to Mark of Thunderstruck Motors a few days ago. I thought the a DC motor was the answer, I believe it was the same you spoke of. Mark thought an A/C motor would be best in my case, he suggested the AC-09 Kit, he also suggested a reduction of 4-1. And a prop w/ a high pitch. The following is the data from the website.
> >
> > This Kit features a Curtis 1236-5301 controller that operates at 36-48V and can draw up to 350A producing up to 18HP and 75ft-lbs of torque. This kit works very well in a medium size sail boat, motorcycle or kart.
> > Peak HP 18
> > Peak TQ 75 ft lbs
> > Controller Weight 9.1lbs
> > Motor Weight 46lbs
> >
> >
> > This Kit includes
> > - Curtis 1236-5301 AC Controller
> > - Hiperformance EVs AC15 6.7" x 11" NEMA C Face, 7/8" shaft.
> > - Curtis Spyglass 840 Display (dispays: Amps, Voltage, RPM, MPH/KPH, Motor Temp)
> > - Wiring Harness and wiring instructions
> >
> > Do you think this would be the way to go?
> >
> >
> > --- In electricboats@yahoogroups.com, "Eric" <ewdysar@> wrote:
> > >
> > > This has been discussed here before. I posted an analysis of the "Sevcon Brushless Sailboat Kit - 8.5KW" from Thunderstuck in post #17601 on March 3, 2011. Here's some of the salient points:
> > >
> > > "The picture on the website shows what appears to be a Mars ME0907 single stator motor. The manufacturer rates this motor for 100A continuous for 48V DC. That works out to a continuous motor rating of 4.8kW
> > >
> > > The picture shows a Sevcon Millipak controller which is also rated for a 48VDC max power output of 4kW (from the Sevcon webpage). However the Thunderstruck webpage lists a Sevcon Gen-4 275Amp, programmable, regen controller. The only Sevcon Gen-4 controller that mentions 275A in its ratings is the G4827 controller. This controller is rated for 110A continuous (60 minutes)with a maximum nominal voltage of 48VDC. That works out to be almost 5.3kW.
> > >
> > > But a drive system can only be driven as hard as its weakest component. In this case, the ME0907 motor will only take 4.8kW continuous current at 48V. And these ratings are in ideal conditions. In a boat, you will probably find that one of the components will overheat at somewhat less than maximum ratings unless measures are taken to maximize the cooling for each of the key components."
> > >
> > > So at best, the "Sevcon Brushless Sailboat Kit - 8.5KW" looks like it should be rated as 4.8kW, not 8.5kW.
> > >
> > > I would expect that a vendor should be able to provide supporting data for their claimed power ratings in a marine environment. I know that Propulsion Marine states that their 5.5kW drive will operate its rating for an hour with controller and winding temps of less than 100C. In my boat, I've operated above 5kW for 15 minutes with controller and winding temps lower than 75C and backing off to 4kW for less than 10 minutes cooled the motor to 72C. Given my experience, I find James' claims believable. All of the components have manufacturer ratings that are considerably higher, but running slow in a bilge is not an optimum environment.
> > >
> > > Fair winds,
> > > Eric
> > > 1964 Cheoy Lee Bermuda 30 ketch
> > > Marina del Rey, CA
> > >
>

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Re: [Electric Boats] BP oil spill, one year later... why are we into electric boats?

 

Believe me Richard, when 9/11 happened I was seriously looking at getting the boat fully stocked in case we needed to take off at any moment! Had she been electric and more self sufficient then it would have made it even easier to consider! She eventually will be - we're working toward that point.  The fact that electric is always ready to go is a nice plus - here on the Chesapeake where we have some delightful winter days, it's fun to be able to take your boat out when others are under wraps until spring. We do that with our 21' motor launch.  In fact, we were the only boat available in Dec. to bring Santa to the children's Christmas party! We hopped in, turned on the controller and off we went to pick up St. Nick! I love having electric as a means of powering a boat.


Sally

On Wed, Apr 27, 2011 at 5:22 PM, Richard <rwsandersii@hotmail.com> wrote:
 

Another more practical and immediate arguement might be that an electric boat with it's own power supply (wind, solar, regeneration) is a great alternative dwelling in an emergency.
I know this is a bit of a stretch, because many boats go into storage in the winter (and some are more vulnerable than your home), but hey any justification helps when you are "throwing money into a hole in the water" right?
Richard



--- In electricboats@yahoogroups.com, Kevin Pemberton <pembertonkevin@...> wrote:
>
> Myles,
>
> I have kind of avoided this thread but what the heck. Off grid makes
> incandescent lighting a large energy user. This is of course minor in
> comparison to other items in the home. If people would quit thinking
> inside the box and see other options for the larger energy users I think
> we could all benefit. Consider that for most places in the US we can
> receive 1000W heat energy per meter square. After losses we will likely
> only collect 500W per meter square. This figure is still pretty good
> considering what we can expect from a square meter of PV panels. This
> heat can heat the house, water, and make ice.
>
> Our real problem today is people are spoiled by quick easy energy. With
> rising prices many will consider the cost and many may switch to lower
> power energy supplies, but we have short memories and will soon forget
> sticker shock, reverting to our old ways.
>
> When Thomas Edison spoke of his new development, the nickel iron
> battery, the ICE had not yet taken complete control of the market, but
> his thoughts on the matter were still that he would take a ton of coal
> any day. Development in the electric vehicle lags because convenience
> won, not because it was better for anyone. For those that believe it is
> best to become green will change, not because it will ever be easy, but
> because they can't justify continuing down the road that has reduced the
> US to what it is today.
>
> Oil spills, Fracking, and other ecology nightmares that feed our hunger
> for power likely will not change. I commend anyone that considers their
> part in the fight. We will likely not be noticed but that seems not to
> matter among those that won't sell their ?#?#?# (you fill in the
> blank). Don't expect the world to change however unless things fall
> apart, and we go back into the dark ages.
>
> Kevin Pemberton
>
> On 04/23/2011 10:37 AM, Myles Twete wrote:
> >
> > Brief Off-topic response: Lighting often is but a small fraction of
> > one’s home electric usage. In our case, our water heater uses 50-70%
> > of our electricity and the refrigerator comes in 2^nd place---after
> > that, our washer/dryer usage. Then I’d guess it’s a close race
> > between lighting and all the gadgets plugged in without timers or
> > Energy Star ratings.
> >
> > So we could go 100% LED and it wouldn’t help us much at all.
> >
> > Given your focus on LED lighting, I’d guess you are heating your home
> > and water with natural gas…

> >
> > -mt
> >
> > *From:*electricboats@yahoogroups.com
> > [mailto:electricboats@yahoogroups.com] *On Behalf Of *Mike
> > *Sent:* Saturday, April 23, 2011 5:09 AM
> > *To:* electricboats@yahoogroups.com
> > *Subject:* Re: [Electric Boats] BP oil spill, one year later... why
> > are we into electric boats?
> >
> > My motivation is to just do it! Don't wait or depend on government or
> > industry. Use what you can now and buy or build what you need to suit
> > your needs. Eventually, if you have a system that works reliably and
> > economically others will be interested in too. But, first it has to
> > meet your needs. For example four years ago my 1986 Mazda 323 just
> > stopped running. Even though it had only 76,000 miles on it finding
> > parts was getting to be a problem. So I needed a new car. I could have
> > gone out an bought a Prius but, it did not make sense to buy it
> > economically for the amount and type of miles I drive. So I bought a
> > low end Honda at 1/3 the cost. It meet my needs and I was able to
> > convert my boat to EP with the money saved. I thought about the idea
> > of converting to electric propulsion the same way. Thinking about the
> > pros and cons. I'm currently converting my house to a solar powered
> > LED lighting system. I can't afford one of those systems costing
> > thousands of dollars even after the government tax credits and the
> > hoops you have to jump through to get them. I'm doing it myself little
> > by little, room by room. I now have a systems that meets my needs
> > powered entirely by the sun at a reasonable price. Every grid
> > connected light I don't turn on is not only good for the environment
> > it is also good for my wallet as I'm not using grid power for most of
> > the lighting and of course if a storm should knock out power my house
> > will still be lit. All from one 75 watt solar panel. Like EP in my
> > boat it will probably be more reliable than the grid power in the long
> > run too. What got me thinking about my house LED lighting system? My
> > experience living on my boat for half the year. I saw how things were
> > working on my boat after I started converting the lights on board to
> > LED's. I thought why won't this work in my house? Why not indeed! So I
> > just did it. Other benefits followed. Like Greg I discovered going to
> > EP also made me a better sailor but, it also made me not hesitate to
> > call on using my electric propulsion system when sailing too! Unlike
> > when I would hate to have to fire up the noisy vibrating diesel. Now I
> > now don't mind turning on the switch to help move the boat along when
> > I need to. So it has also enhanced the sailing experience in a very
> > positive way too.
> >
> > Capt. Mike
> >
> > http://biankablog.blogspot.com <http://biankablog.blogspot.com/>
> >
> >
> >
> > --- On *Sat, 4/23/11, Richard /<rwsandersii@...>/* wrote:
> >
> >
> > From: Richard <rwsandersii@...>

> > Subject: Re: [Electric Boats] BP oil spill, one year later... why
> > are we into electric boats?
> > To: electricboats@yahoogroups.com
> > Date: Saturday, April 23, 2011, 3:14 AM
> >
> > I think we could get there if the utilities weren't afraid of a
> > decentralized system. If they were forward thinking, they could
> > charge a little per "transaction" and actually make more.
> > The U.S. (from what I have read) developed photoelectric cells
> > with tax dollars, but when the incentives disappeared, the
> > technology was sold and we rank 4th behind Brazil in production
> > and only because there is a Japanese owned plant here.
> > When I read or watch history from the depression era or WW2 it is
> > really sad because we are losing or place in the world.
> > Every home and building could be a solar source, we could be
> > investing in artificial leaves that hold promise as cheaper
> > alternatives to existing photoelectrics with no toxic metals.
> > I don't know if anyone here is following the Velux Oceans 5 race
> > (An American Brad Van Liew on Le Pingouin is in first), but the
> > focus is on self-sufficient energy systems.
> > Richard
> >
> > --- In electricboats@yahoogroups.com
> > <http://us.mc840.mail.yahoo.com/mc/compose?to=electricboats%40yahoogroups.com>,

> > "Greg Martin" <ffmagellan@> wrote:
> > >
> > > James and Richard, yeah they're probably all bad... This is
> > really about energy self sufficiency. Wouldn't it be great if we
> > could supply all our own energy? Being completely energy self
> > sufficient by your own renewable means is the holy grail, I think.
> > Know of any good examples of people doing this? Let's follow their
> > lead!
> > >
> > > -Greg
> > >
> > > --- In electricboats@yahoogroups.com
> > <http://us.mc840.mail.yahoo.com/mc/compose?to=electricboats%40yahoogroups.com>,

> > "Richard" <rwsandersii@> wrote:
> > > >
> > > > James,
> > > > It is hard to buy gas anywhere and be responsible. I won't buy
> > from Exxon (they fought reasonable payouts to victims of their
> > spill and fought them all the way to the U.S. Supreme Court).
> > > > Shell has supported the regime in Nigeria that killed
> > environmental activists including Ben Saro Siwa.
> > > > Now BP.
> > > > Here's a great summary by the Sierra Club of the positives and
> > negatives of many of the companies:
> > > > http://www.sierraclub.org/sierra/pickyourpoison/
> > > > Richard
> > > >
> > > > --- In electricboats@yahoogroups.com
> > <http://us.mc840.mail.yahoo.com/mc/compose?to=electricboats%40yahoogroups.com>,

> > James Sizemore <james@> wrote:
> > > > >
> > > > > BP is just incompetent, I would buy gas from them a hundred
> > times before buying gas at an station that sells Exxon gas. Exxon
> > funds nearly 100% of all anti global warming pesudo-science. I
> > have not bought gas from Exxon in over a decade and would run out
> > of gas first.
> > > > >
> > > > > On Apr 20, 2011, at 1:12 PM, Pitt Bolinate wrote:
> > > > >
> > > > > >
> > > > > > I have an Electric Yacht 360ibi on the big boat and I
> > bought a torqeedo and a whole bunch of solar panels at the show,
> > to try to get of the gas completely. Except for my hookah dive
> > compressor there isn't an ICE onboard.
> > > > > >
> > > > > > I see BP selling gas in my area for 50c a gallon less than
> > everyone else? I cannot believe what the power of the dollar
> > has?..would you shop at a local store if the parent company killed
> > an ocean?
> > > > > >
> > > > > > Sent from my iPad
> > > > > >
> > > > > > On Apr 20, 2011, at 8:46, "Greg Martin" <ffmagellan@> wrote:
> > > > > >
> > > > > >>
> > > > > >> On the anniversary of the big oil spill in the Gulf of
> > Mexico, which still hasn't been cleaned up, and in response to the
> > apology by the CEO of Transocean, for having a good year last year
> > (and being shamed into donating his obscene bonus to charity), I
> > just think it might be time to ask ourselves why we're into
> > electric boats? Is it because the technology makes the best sense,
> > for certain applications, ...or... are we trying to take a bite
> > out of BP (i.e. the oil industry)?
> > > > > >>
> > > > > >> Keep it charged!
> > > > > >> -Greg
> > > > > >>
> > > > > >
> > > > > >
> > > > >
> > > >
> > >
> >
> >
>


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Re: [Electric Boats] BP oil spill, one year later... why are we into electric boats?

 

Good points Kevin! Thanks for not avoiding this thread and saying what needed to be said.


Sally

On Wed, Apr 27, 2011 at 4:57 PM, Kevin Pemberton <pembertonkevin@gmail.com> wrote:
 

Myles,

I have kind of avoided this thread but what the heck.  Off grid makes incandescent lighting a large energy user. This is of course minor in comparison to other items in the home.  If people would quit thinking inside the box and see other options for the larger energy users I think we could all benefit.  Consider that for most places in the US we can receive 1000W heat energy per meter square.  After losses we will likely only collect 500W per meter square. This figure is still pretty good considering what we can expect from a square meter of PV panels.  This heat can heat the house, water, and make ice.

Our real problem today is people are spoiled by quick easy energy. With rising prices many will consider the cost and many may switch to lower power energy supplies, but we have short memories and will soon forget sticker shock, reverting to our old ways.

When Thomas Edison spoke of his new development, the nickel iron battery, the ICE had not yet taken complete control of the market, but his thoughts on the matter were still that he would take a ton of coal any day.  Development in the electric vehicle lags because convenience won, not because it was better for anyone.  For those that believe it is best to become green will change, not because it will ever be easy, but because they can't justify continuing down the road that has reduced the US to what it is today.

Oil spills, Fracking, and other ecology nightmares that feed our hunger for power likely will not change.  I commend anyone that considers their part in the fight.  We will likely not be noticed but that seems not to matter among those that won't sell their ?#?#?#  (you fill in the blank).  Don't expect the world to change however unless things fall apart, and we go back into the dark ages.

Kevin Pemberton



On 04/23/2011 10:37 AM, Myles Twete wrote:
 

Brief Off-topic response: Lighting often is but a small fraction of one's home electric usage.  In our case, our water heater uses 50-70% of our electricity and the refrigerator comes in 2nd place---after that, our washer/dryer usage.  Then I'd guess it's a close race between lighting and all the gadgets plugged in without timers or Energy Star ratings.

So we could go 100% LED and it wouldn't help us much at all.

Given your focus on LED lighting, I'd guess you are heating your home and water with natural gas…

-mt

 

From: electricboats@yahoogroups.com [mailto:electricboats@yahoogroups.com] On Behalf Of Mike
Sent: Saturday, April 23, 2011 5:09 AM
To: electricboats@yahoogroups.com
Subject: Re: [Electric Boats] BP oil spill, one year later... why are we into electric boats?

 

 

My motivation is to just do it! Don't wait or depend on government or industry. Use what you can now and buy or build what you need to suit your needs. Eventually, if you have a system that works reliably and economically others will be interested in too. But, first it has to meet your needs.  For example four years ago my 1986 Mazda 323 just stopped running. Even though it had only 76,000 miles on it finding parts was getting to be a problem. So I needed a new car. I could have gone out an bought a Prius but, it did not make sense to buy it economically for the amount and type of miles I drive. So I bought a low end Honda at 1/3 the cost. It meet my needs and I was able to convert my boat to EP with the money saved. I thought about the idea of converting to electric propulsion the same way. Thinking about the pros and cons.  I'm currently converting my house to a solar powered LED lighting system. I can't afford one of those systems costing thousands of dollars even after the government tax credits and the hoops you have to jump through to get them. I'm doing it myself little by little, room by room. I now have a systems that meets my needs powered entirely by the sun at a reasonable price. Every grid connected light I don't turn on is not only good for the environment it is also good for my wallet as I'm not using grid power for most of the lighting and of course if a storm should knock out power my house will still be lit. All from one 75 watt solar panel.  Like EP in my boat it will probably be more reliable than the grid power in the long run too. What got me thinking about my house LED lighting system? My experience living on my boat for half the year. I saw how things were working on my boat after I started converting the lights on board to LED's. I thought why won't this work in my house? Why not indeed! So I just did it. Other benefits followed. Like Greg I discovered going to EP also made me a better sailor but, it also made me not hesitate to call on using my electric propulsion system when sailing too! Unlike when I would hate to have to fire up the noisy vibrating diesel. Now I now don't mind turning on the switch to help move the boat along when I need to. So it has also enhanced the sailing experience in a very positive way too.

 

Capt. Mike



--- On Sat, 4/23/11, Richard <rwsandersii@hotmail.com> wrote:


From: Richard <rwsandersii@hotmail.com>
Subject: Re: [Electric Boats] BP oil spill, one year later... why are we into electric boats?
To: electricboats@yahoogroups.com
Date: Saturday, April 23, 2011, 3:14 AM

 

I think we could get there if the utilities weren't afraid of a decentralized system. If they were forward thinking, they could charge a little per "transaction" and actually make more.
The U.S. (from what I have read) developed photoelectric cells with tax dollars, but when the incentives disappeared, the technology was sold and we rank 4th behind Brazil in production and only because there is a Japanese owned plant here.
When I read or watch history from the depression era or WW2 it is really sad because we are losing or place in the world.
Every home and building could be a solar source, we could be investing in artificial leaves that hold promise as cheaper alternatives to existing photoelectrics with no toxic metals.
I don't know if anyone here is following the Velux Oceans 5 race (An American Brad Van Liew on Le Pingouin is in first), but the focus is on self-sufficient energy systems.
Richard

--- In electricboats@yahoogroups.com, "Greg Martin" <ffmagellan@...> wrote:
>
> James and Richard, yeah they're probably all bad... This is really about energy self sufficiency. Wouldn't it be great if we could supply all our own energy? Being completely energy self sufficient by your own renewable means is the holy grail, I think. Know of any good examples of people doing this? Let's follow their lead!
>
> -Greg
>
> --- In electricboats@yahoogroups.com, "Richard" <rwsandersii@> wrote:
> >
> > James,
> > It is hard to buy gas anywhere and be responsible. I won't buy from Exxon (they fought reasonable payouts to victims of their spill and fought them all the way to the U.S. Supreme Court).
> > Shell has supported the regime in Nigeria that killed environmental activists including Ben Saro Siwa.
> > Now BP.
> > Here's a great summary by the Sierra Club of the positives and negatives of many of the companies:
> > http://www.sierraclub.org/sierra/pickyourpoison/
> > Richard
> >
> > --- In electricboats@yahoogroups.com, James Sizemore <james@> wrote:
> > >
> > > BP is just incompetent, I would buy gas from them a hundred times before buying gas at an station that sells Exxon gas. Exxon funds nearly 100% of all anti global warming pesudo-science. I have not bought gas from Exxon in over a decade and would run out of gas first.
> > >
> > > On Apr 20, 2011, at 1:12 PM, Pitt Bolinate wrote:
> > >
> > > >
> > > > I have an Electric Yacht 360ibi on the big boat and I bought a torqeedo and a whole bunch of solar panels at the show, to try to get of the gas completely. Except for my hookah dive compressor there isn't an ICE onboard.
> > > >
> > > > I see BP selling gas in my area for 50c a gallon less than everyone else? I cannot believe what the power of the dollar has?..would you shop at a local store if the parent company killed an ocean?
> > > >
> > > > Sent from my iPad
> > > >
> > > > On Apr 20, 2011, at 8:46, "Greg Martin" <ffmagellan@> wrote:
> > > >
> > > >>
> > > >> On the anniversary of the big oil spill in the Gulf of Mexico, which still hasn't been cleaned up, and in response to the apology by the CEO of Transocean, for having a good year last year (and being shamed into donating his obscene bonus to charity), I just think it might be time to ask ourselves why we're into electric boats? Is it because the technology makes the best sense, for certain applications, ...or... are we trying to take a bite out of BP (i.e. the oil industry)?
> > > >>
> > > >> Keep it charged!
> > > >> -Greg
> > > >>
> > > >
> > > >
> > >
> >
>




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[Electric Boats] Re: How do you measure how much battery life is left whlile you are out sailing?

 

The Cycle Analyst displays AH consumed among other info. You reset it to zero after a charge. My bank is 100 ah total and I typically use 20 ah on a day sail.
Doug

--- In electricboats@yahoogroups.com, "m8trixman" <pb@...> wrote:
>
> What is the best way to measure what percent of battery life is left while you are out motoring?
>
> Thanks for taking the time to chime in on this question...
>
> Brett
>

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[Electric Boats] Re: how to determine maximum speed/ torque

 



--- In electricboats@yahoogroups.com, Roland Kruijer <martine_roland@...> wrote:
>
>
> Hello group,
>
> My name is Roland Kruijer and I am a memeber since about two years now.
>
> I own a little electric boat like this one: http://www.electraboat.com/
>
> I changed the motor in the boat for this one: jpg P7051547. I have attached the specifications of this motor in pdf.
> That motor has a controller: jpg PA101651
>
> It all works ok but I think the motor can do better.
> The boat has two 12V 210 aH batteries in series so 24V 210 aH. The motor uses a v-belt to transfer the power to the propellor axle.
> On the motor axle it has a 100 mm pulley.
> On the propellor axle I have a 74 mm pulley which has a 8.2" X 12 pitch propellor.
> Oh, I know that the hull speed can be about 8 - 9 kph. The boat weighs about 400 kg including me.
>
> It seems the motor doesn't get to 1100 rpm, allthough I don't have a rpm meter. Does this happen because the motor can't get to this rpm because of the pulleysizes? Or is the resistance from the propellor(water) too big to get to this rpm?
>
> I have experienced a bit with different pulley size but I'd like to know if there's a way to calculate the best performance possible with this motor. I want some more speed/torque from this engine in relation to the propellor / waterresistance
>
> What would be the best proportion of pulleys for this given motor?
> I am also thinking about placing an extra battery to run the motor on 36 V. Would that give the boat the extra power I want?
>
> Ok guys, I know my boat is not as big as most boats I see here in the group, but maybe someone can help me figure out what is the best way to go!
>
> Thanks so far,
>
> Roland Kruijer
> The Netherlands
>

Hi Roland. There's a simple answer to your question but not a simple solution, but then again, they have software for everything these days.

Performance with any motor depends on a lot of factors, and I guess you can use a wide range of motors to do the job. But performance depends on eight or ten critical factors:
1) Look at the motor's perf. charts to find its limitations: Its rpm at 24 volts; its max. continuous (or "cruise") torque rating; calculations and judgments should only focus on the "plateau" section of the chart's efficiency curve. Now you're ready to configure your prop and pulleys, whose job is not only to balance everything smoothly but to eliminate over-amping (a.k.a. overtorquing, overheating, straining).

2) Download David Rasberry's free "E-Boat Model Spreadsheet" so you don't have to get into a complicated mish-mash of math. (Other members of this group can probably advise you on its accuracy or authenticity.) What you do with it is keep changing the (a) prop diameter, (b) maximum cruising rpm, and (c) reduction ratio (1:1 would be nice but prop torque is more important). Try determining the torque requirement based on weight and hull resistance, and acceleration. The goal is achieving desired speed with minimum horsepower. But for every change in the spreadsheet, you need to check its impact on hp-torque-voltage-rpm, with the goal of gobbling the least amperage, while exploiting the motor's potential.

Look at the pitch result on the spreadsheet. One clue to efficiency is keeping the diameter number lower than the pitch: 10x12 is better than 12x7. Another one, of course, is opting for lower prop speed. Diameter changes have the biggest impact.

Does this help or am I being redundant?

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Re: [Electric Boats] Sea going liveaboard

 


Hi Robert,
I'd be keen to hear how your project develops.
Best regards from sunny Scotland.
Brian

--- In electricboats@yahoogroups.com, "Robert E." <relmason@...> wrote:
>
> Hey Brian,
> Parts of my electric drive are arriving and I hope to get down to real
> business soon. I'll keep you posted.
>
> Robert
>
>
>
>
> On Mon, Apr 11, 2011 at 4:40 PM, BRIAN JONES
> <benachiesween@...>wrote:
>
> >
> >
> > Hi Robert,
> > I would appreciate any information on your project and its progress.
> > I omitted to mention my plan is for a motor cruiser rather than a sailboat
> > but I'm sure its a matter of tailoring the package to the boat.
> > I plan to do my cruising during the summer months and hope to provide the
> > power from PVs, a suitable bank of batteries and a backup generator.
> > Regards,
> > Brian
> >
> >
> > --- On *Mon, 11/4/11, Robert E. <relmason@...>* wrote:
> >
> >
> > From: Robert E. <relmason@...>
> > Subject: Re: [Electric Boats] Sea going liveaboard
> > To: electricboats@yahoogroups.com
> > Date: Monday, 11 April, 2011, 22:09
> >
> >
> > I have a 6.5 kW Propulsion Marine drive on order going in my 35' Columbia
> > which displaces 13,900 lbs. My wife and I will be moving aboard full time
> > after the conversion. I can keep you posted with results.
> >
> > Robert
> >
> >
> >
> > On Mon, Apr 11, 2011 at 3:22 PM, BRIAN <benachiesween@...<http://uk.mc862.mail.yahoo.com/mc/compose?to=benachiesween@...>
> > > wrote:
> >
> >
> > I'm looking to buy a 35-40ft displacement boat as a liveaboard for
> > cruising west coast Scotland. I've looked at a number of boats and a few of
> > them require new engines which got me thinking of alternative power for
> > propulsion. Anyone on this site have an electric vessel of this size/weight?
> > Brian
> >
> >
> >
> >
> > --
> > *Robert E*.
> >
> > ~~*(*\_~~~~~*(*\_~~~
> > ~~~~*(*\_~~~~*(*\_~~
> >
> >
> >
>
>
>
> --
> *Bob*
> *
> *
> *
> *
>
> ~~*(*\_~~~~~*(*\_~~~
> ~~~~*(*\_~~~~*(*\_~~
>

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