Wednesday, August 31, 2011

[Electric Boats] Re: battery article

 

Actually I have a friend at SCE, that was a typo... :)

--- In electricboats@yahoogroups.com, "Eric" <ewdysar@...> wrote:
>
> Hi Kirk,
>
> Good article. It has been almost three years since the article was published, I wonder if they've moved the experiment out of the laboratory and into the field with a full size pack in a car on the road. I have a fiend that works as a program manager at SCE, I'll have to see if she can dig up an update on this initiative.
>
> In the mean time, has anybody found any specs of rechargable Li-Ion batteries from Saft?
>
> Fair winds,
> Eric
> Marina del Rey, CA
>

__._,_.___
Recent Activity:
MARKETPLACE
A bad score is 579. A good idea is checking yours at freecreditscore.com.
.

__,_._,___
Posted by at No comments:

[Electric Boats] Re: battery article

 

Hi Kirk,

Good article. It has been almost three years since the article was published, I wonder if they've moved the experiment out of the laboratory and into the field with a full size pack in a car on the road. I have a fiend that works as a program manager at SCE, I'll have to see if she can dig up an update on this initiative.

In the mean time, has anybody found any specs of rechargable Li-Ion batteries from Saft?

Fair winds,
Eric
Marina del Rey, CA

--- In electricboats@yahoogroups.com, Kirk McLoren <kirkmcloren@...> wrote:
>
>
>
>  http://www.gizmag.com/electric-car-batteries-demonstrate-180000-plus-mile-lifespan/10491/
>

__._,_.___
Recent Activity:
MARKETPLACE
A bad score is 579. A good idea is checking yours at freecreditscore.com.
.

__,_._,___
Posted by at No comments:

[Electric Boats] battery article

 

__._,_.___
Recent Activity:
MARKETPLACE
A bad score is 596. A good idea is checking yours at freecreditscore.com.
.

__,_._,___
Posted by at No comments:

[Electric Boats] Re: No sailed, solar powered cruiser (40-60 feet)

 

Like Denny said, the prismatic coefficient is a major factor that takes more than D/L and wetted area into consideration. Here's a link to a quick explanation ofthe concept:

http://www.navweaps.com/index_tech/tech-004.htm

Fair winds,
Eric
Marina del Rey, CA

--- In electricboats@yahoogroups.com, "Jeremy" <jeremy_harris_uk@...> wrote:
>
> Whilst increasing waterline length gives a theoretical increase in "maximum displacement speed" (which is a slightly flawed concept for other reasons), drag, and hence power consumption, is very much determined by D/L, the displacement/length ratio, rather than just waterline length alone.
>
> This is because drag, at least at speeds below the onset of significant wave-making, is massively dominated by wetted area. The greater the wetted are the slower the boat will be on a given amount of power, as long as the length is such as to ensure that the hull is not operating in the region where wave-making drag starts to make itself felt.
>
> --- In electricboats@yahoogroups.com, "\"hanermo\" - CNC 6-axis Designs" <gcode.fi@> wrote:
> >
> > The only important characteristic is waterline length.
> >
> > Longer = faster.
> >
> > > Hey Dan,
> > > Do you have pictures of the mods you made to optimize the displacement
> > > hull? I am still learning all this stuff, so a website or any pointers
> > > you could provide to us would be extremely useful.
> > >
> > > Much obliged,
> > > Bill
> > >
> >
>

__._,_.___
Recent Activity:
MARKETPLACE
A bad score is 598. A bad idea is not checking yours, at freecreditscore.com.
.

__,_._,___
Posted by at No comments:

[Electric Boats] Re: No sailed, solar powered cruiser (40-60 feet)

 

Whilst increasing waterline length gives a theoretical increase in "maximum displacement speed" (which is a slightly flawed concept for other reasons), drag, and hence power consumption, is very much determined by D/L, the displacement/length ratio, rather than just waterline length alone.

This is because drag, at least at speeds below the onset of significant wave-making, is massively dominated by wetted area. The greater the wetted are the slower the boat will be on a given amount of power, as long as the length is such as to ensure that the hull is not operating in the region where wave-making drag starts to make itself felt.

--- In electricboats@yahoogroups.com, "\"hanermo\" - CNC 6-axis Designs" <gcode.fi@...> wrote:
>
> The only important characteristic is waterline length.
>
> Longer = faster.
>
> > Hey Dan,
> > Do you have pictures of the mods you made to optimize the displacement
> > hull? I am still learning all this stuff, so a website or any pointers
> > you could provide to us would be extremely useful.
> >
> > Much obliged,
> > Bill
> >
>

__._,_.___
Recent Activity:
MARKETPLACE
A bad score is 598. A bad idea is not checking yours, at freecreditscore.com.
.

__,_._,___
Posted by at No comments:

[Electric Boats] Re: No sailed, solar powered cruiser (40-60 feet)

 

And have her be double-ended at the waterline (no transom-dragging, please!)

-Tom

--- In electricboats@yahoogroups.com, Dennis Wolfe <dwolfe@...> wrote:
>
> Prismatic
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
> Prismatic coefficient describes the fineness of the hull. There is an
> optimum (lowest drag) coefficient for every speed/ length ratio.
>
> A fine lined sailing hull might have a PC as low as 0.5 while a high
> speed planing hull would be upwards of 0.7
>
> A flat bottom, rectangular plan view barge has a PC of 1.0
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
> On 8/31/2011 4:04 AM, "hanermo" - CNC 6-axis Designs wrote:
> >
> > The only important characteristic is waterline length.
> >
> > Longer = faster.
> >
> >> Hey Dan,
> >> Do you have pictures of the mods you made to optimize the
> >> displacement hull? I am still learning all this stuff, so a website
> >> or any pointers you could provide to us would be extremely useful.
> >>
> >> Much obliged,
> >> Bill
> >>
> >
> >
>

__._,_.___
Recent Activity:
MARKETPLACE
A bad score is 579. A good idea is checking yours at freecreditscore.com.
.

__,_._,___
Posted by at No comments:

Re: [Electric Boats] Re: No sailed, solar powered cruiser (40-60 feet)

 

Prismatic











































Prismatic coefficient describes the fineness of the hull.  There is an optimum (lowest drag) coefficient for every speed/ length ratio.

A fine lined sailing hull might have a PC as low as 0.5 while a high speed planing hull would be upwards of 0.7

A flat bottom, rectangular plan view barge has a PC of 1.0































On 8/31/2011 4:04 AM, "hanermo" - CNC 6-axis Designs wrote:

 

The only important characteristic is waterline length.

Longer = faster.

 

Hey Dan,
Do you have pictures of the mods you made to optimize the displacement hull? I am still learning all this stuff, so a website or any pointers you could provide to us would be extremely useful.

Much obliged,
Bill



__._,_.___
Recent Activity:
MARKETPLACE
A bad score is 579. A good idea is checking yours at freecreditscore.com.
.

__,_._,___
Posted by at No comments:

Re: [Electric Boats] Re: No sailed, solar powered cruiser (40-60 feet)

 

The only important characteristic is waterline length.

Longer = faster.

 

Hey Dan,
Do you have pictures of the mods you made to optimize the displacement hull? I am still learning all this stuff, so a website or any pointers you could provide to us would be extremely useful.

Much obliged,
Bill


__._,_.___
Recent Activity:
MARKETPLACE
A bad score is 598. A bad idea is not checking yours, at freecreditscore.com.
.

__,_._,___
Posted by at No comments:

Tuesday, August 30, 2011

RE: [Electric Boats] Re: Military Batteries

 

When I’ve ever heard of SAFT it was in the context of rechargeable EV-scale flooded NiCd cells…but maybe I’m wrong.

-MT

 

From: electricboats@yahoogroups.com [mailto:electricboats@yahoogroups.com] On Behalf Of Eric
Sent: Tuesday, August 30, 2011 1:26 PM
To: electricboats@yahoogroups.com
Subject: [Electric Boats] Re: Military Batteries

 

 

Hi Steve,

Whereas Saft's literature says that they make rechargable lithium cells, it looks like the bulk of their products are one use items (non-rechargable). Doing a quick search, they do have high energy density by weight, however, there are some limitations to the cells. The high energy version of the "C" cells will sustain a C/4 discharge rate, they should last around 3-4 hours at that rate. Their regular "C" cells will sustain only a C/50 discharge rate.

So if one bought a bunch of these cells, 15 cells in series would create a 7.7Ah x 48V nominal (54V actual) battery. 20 groups in parallel of 15 cells in series (300 cells total) will create a battery bank that specs to 154Ah x 48V (7.3kWh) and the whole package weighs only 40 lbs. Compare that to my prismatic Lithium cells that rate to 8kWh and weigh 200 lbs. The draw on the Saft batteries should be kept to less than 39A (about 1900W). My batteries will sustain a 480A draw without damage.

Once the Saft batteries were discharged, you would throw them away. The bare Saft cells would cost $6900 though the vendor that I found online. My prismatic cells cost $3400 shipped including simple BMS. My cells can be recharged.

I guess that one could put together a one-time only emergency battery pack (they do have a very good shelf life) but that would be too expensive for my budget. :)

If anyone can find specs on Saft rechargable lithium cells, please post the link and I can do the math for a rechargable pack....

Thanks,
Eric

--- In electricboats@yahoogroups.com, Steve Dolan <sdolan@...> wrote:
>
> I was just talking to a guy who can get me battery packs from a company called Saft. He even gave me a couple "C" cells t play with. Most of their stuff looks a little dangerous but since we were talking batteries I thought I would see what the brain trust thought. Yes they are expensive!
>
> http://www.army-technology.com/contractors/electrical/saft/
>
> Steve in Solomons MD
>

__._,_.___
Recent Activity:
MARKETPLACE
A bad score is 579. A good idea is checking yours at freecreditscore.com.
.

__,_._,___
Posted by at No comments:

[Electric Boats] Re: Military Batteries

 

Hi Steve,

Whereas Saft's literature says that they make rechargable lithium cells, it looks like the bulk of their products are one use items (non-rechargable). Doing a quick search, they do have high energy density by weight, however, there are some limitations to the cells. The high energy version of the "C" cells will sustain a C/4 discharge rate, they should last around 3-4 hours at that rate. Their regular "C" cells will sustain only a C/50 discharge rate.

So if one bought a bunch of these cells, 15 cells in series would create a 7.7Ah x 48V nominal (54V actual) battery. 20 groups in parallel of 15 cells in series (300 cells total) will create a battery bank that specs to 154Ah x 48V (7.3kWh) and the whole package weighs only 40 lbs. Compare that to my prismatic Lithium cells that rate to 8kWh and weigh 200 lbs. The draw on the Saft batteries should be kept to less than 39A (about 1900W). My batteries will sustain a 480A draw without damage.

Once the Saft batteries were discharged, you would throw them away. The bare Saft cells would cost $6900 though the vendor that I found online. My prismatic cells cost $3400 shipped including simple BMS. My cells can be recharged.

I guess that one could put together a one-time only emergency battery pack (they do have a very good shelf life) but that would be too expensive for my budget. :)

If anyone can find specs on Saft rechargable lithium cells, please post the link and I can do the math for a rechargable pack....

Thanks,
Eric

--- In electricboats@yahoogroups.com, Steve Dolan <sdolan@...> wrote:
>
> I was just talking to a guy who can get me battery packs from a company called Saft. He even gave me a couple "C" cells t play with. Most of their stuff looks a little dangerous but since we were talking batteries I thought I would see what the brain trust thought. Yes they are expensive!
>
> http://www.army-technology.com/contractors/electrical/saft/
>
> Steve in Solomons MD
>

__._,_.___
Recent Activity:
MARKETPLACE
A bad score is 596. A good idea is checking yours at freecreditscore.com.
.

__,_._,___
Posted by at No comments:

[Electric Boats] Re: Military Batteries

 

Hi Steve,
Not sure what you mean when you say they look dangerous, but I suppose if they are powering a weapon system that you're on the wrong end of...
Anyhow, FWIW, I do know that Saft has been selling batteries to the civilian aircraft market for many years. I've seen them installed on a lot of airplanes. Based on that observation alone I'm pretty sure they are a well-established company, and because they sell to the military and aerospace markets it's probably safe to assume they have a robust quality control program. Keep in mind, however, that you'd be paying a premium to cover the QC paperwork that those industries require, which doesn't necessarily guarantee a superior product.
Jim

--- In electricboats@yahoogroups.com, Steve Dolan <sdolan@...> wrote:
>
> I was just talking to a guy who can get me battery packs from a company called Saft. He even gave me a couple "C" cells t play with. Most of their stuff looks a little dangerous but since we were talking batteries I thought I would see what the brain trust thought. Yes they are expensive!
>
> http://www.army-technology.com/contractors/electrical/saft/
>
> Steve in Solomons MD
>

__._,_.___
Recent Activity:
MARKETPLACE
A bad score is 598. A bad idea is not checking yours, at freecreditscore.com.
.

__,_._,___
Posted by at No comments:

[Electric Boats] Re: No sailed, solar powered cruiser (40-60 feet)

 

Hey Dan,
Do you have pictures of the mods you made to optimize the displacement hull? I am still learning all this stuff, so a website or any pointers you could provide to us would be extremely useful.

Much obliged,
Bill

--- In electricboats@yahoogroups.com, danbollinger <no_reply@...> wrote:
>
> That should give you about 300 square feet of solar panel. The boat is powered by two 300Hp V-8 engines. That tells us that it has a planing hull form. After removing and selling the engines and drive train, you'll have room for a lot of batteries in those hulls. Right now, it has 8.5 knots hull speed. You'll want to have the hulls modified to make them displacement hulls to reduce drag. I did that to my 12' jon boat by adding hull extensions to the transom and it improved the cruising speed, and therefore range, too.
>
> --- In electricboats@yahoogroups.com, James Sizemore <james@> wrote:
> >
> > Just on a whim I went searching for his 65000 dollar cat in good condition ie floats. And I was able to find one. If he removes the fly bridge and the crappy RV a/c, he would have about 15 by 30 feet for solar cells, it being aluminum it is surprisingly light 7500 pounds, it might make a pretty decent electric power boat.
> >
> >
> > http://www.yachtworld.com/core/listing/boatMergedDetails.jsp?boat_id=2385056&checked_boats=2385056&ybw=&units=Feet&currency=USD&access=Public&listing_id=1779&url=&imc=pg-fs
> >
> >
> >
> > On Aug 22, 2011, at 1:24 AM, Kevin Pemberton <pembertonkevin@> wrote:
> >
> > > Hey Bill,
> > >
> > > I would not worry about an array that follows the sun. Consider that
> > > response time would have to be as fast as any wave or other disturbance.
> > > The gain would be lost with constant correction.
> > >
> > > I think most cats used for engines are replaced till the hulls are no
> > > longer sea worthy on such craft. Hope you find one.
> > >
> > > Kevin Pemberton
> > >
> > > On 08/17/2011 10:07 AM, Galstaf wrote:
> > > > How tall would you make the vessel, what should I consider in terms of
> > > > weight and positioning of the array?
> > > > Is there a practical way to make an array of this size "directional",
> > > > i.e. follow the sun.
> > >
> > > --
> > > AspireOne Netbook running Ubuntu 11.04
> > > Safe, Secure, Easy to use, Free Open Source Linux OS.
> > > Leaving Virus worries to the Windows Users!
> > >
> > >
> >
>

__._,_.___
Recent Activity:
MARKETPLACE
A bad score is 579. A good idea is checking yours at freecreditscore.com.
.

__,_._,___
Posted by at No comments:
Subscribe to: Posts (Atom)