DIY 30 horse elctric out board

[Gater Dunn]

id like to see what kind of mileage you could get with this on a Mac

http://youtu.be/_EV2qq2-Lck

[mastreb]

It takes a hull of a lot of battery to get any range at all. Four group 24 batts in series (necessary to get 48V) fully charged is worth about 3nm.

On a keel boat or submarine, making a keel out of lead acid batteries is just fine. But on any other kind of boat, especially trailerable, gasoline weighs so much less per energy density that electric or hybrid just doesn't make sense IMHO. When the next generation of carbon nanomatrix batteries arrives in a few years, pure electrics will start making sense.

[Divecoz]

http://www.youtube.com/watch?v=fpNej1Q35ow

It was out on the water over an hour.. Hitting speeds in excess of 50 MPH .. Thats in or around what 30 + NM's figuring getting out of harbor play time etc etc maybe closer to 50 NM's.. The batteries cannot be too heavy as we look at how that boat sits in the water.. BUT $$$$$$$$$$$$$$$

[wincrasher26]

It will be a great day when these high capacity lithium ion batteries are sorted out and freely available. They were saying in the video that the battery pack is 2700 watt hours (@ 75volts?) and only 30 lbs. You could put a ton of capacity in our existing boats with LiOn batteries if they were in 12v configuration.

An electric outboard would certainly be more in keeping with the idea of a sailboat - quiet!

If you want to go LiOn now - look at this: http://www.batteryspace.com/LiFePO4-Bat ... ttery.aspx

$1250 for a 100aH battery! Only 30 lbs. 4 of them would be a nice pack.

[Steve K]

Thought about this for years, mainly because I hate the engine noise. That's probably one reason I like sailing in the first place.

I know there are electric outboards (around 6hp) that would work for my boat now. I'd still like to build a system of my own though.

I need to motor for about three hours, in certain conditions and this equates to about 1 1/2 to 2 gallons of gasoline now (depending on wind/wave conditions). Also slow motoring in and out of marinas, docking etc.

So, with a 6 to 8 hp electric motor, what kind of battery power do I need, on average

Best Breezes,
Steve K.

[Divecoz]

General ...Rule of thumb / guesstimating.. 750 watts per HP divide by voltage needed showing amps required ..Biggest issue by far, is how much are you willing to invest in batteries..I would love to find out what that ski boat is using to power that 180 HP electric motor and how long it will last..

Thought about this for years, mainly because I hate the engine noise. That's probably one reason I like sailing in the first place.

I know there are electric outboards (around 6hp) that would work for my boat now. I'd still like to build a system of my own though.

I need to motor for about three hours, in certain conditions and this equates to about 1 1/2 to 2 gallons of gasoline now (depending on wind/wave conditions). Also slow motoring in and out of marinas, docking etc.

So, with a 6 to 8 hp electric motor, what kind of battery power do I need, on average

Best Breezes,
Steve K.

[Steve K]

Biggest issue by far, is how much are you willing to invest in batteries.

Yea, exactly what I was thinking.
I thought I might have a small generator on board as a just in case measure, to recharge, if the need ever arose. This would be the exception though, not the rule. So I figure I need about five to six hours of run time total.

But can you imagine cruising along in total quiet. How nice it would be. Funny, I've been told that my outboard is very quiet too, but I sure don't see it that way.

Anyway, just thinking out loud for now.

SK

[Catigale]

Quick math....1 HP is 750 watts, and you need about 6 HP to cruise a power sailor at hull speed

So each hour of cruising will require 4.5 kW of battery power...that's 6 group 24s at 100% depletion

We will all retire with gasoline powered power sailors ....

There is a nice 30HP? torque do out at $23000 .......

[mastreb]

On my brother's 33 ft. Ranger with a 4hp electric motor and four Group 24 bats for a 48v system, we can run his honda EU2000i for eight hours and achieve about a 1/3 charge. Maybe half. Hard to tell with electrical systems. Anyway, you need to be generating about 1.5X the HP rating of the motor with your generator in order to keep up with depletion if you wanted to build a "hybrid". So essentially that means we had to run the generator all day while sailing to guarantee enough power to come back into the marina when we're done.

[Divecoz]

Why did he pick Group 24? I ask that as it seems 30's are really only a little larger and offer considerably more amp hrs..That said last year I tried to sneak a larger battery into my M.C. and after hours of jerking my own chain I gave up and installed a battery that was just a tiny bit smaller..

On my brother's 33 ft. Ranger with a 4hp electric motor and four Group 24 bats for a 48v system, we can run his honda EU2000i for eight hours and achieve about a 1/3 charge. Maybe half. Hard to tell with electrical systems. Anyway, you need to be generating about 1.5X the HP rating of the motor with your generator in order to keep up with depletion if you wanted to build a "hybrid". So essentially that means we had to run the generator all day while sailing to guarantee enough power to come back into the marina when we're done.

[wincrasher26]

If you look at the videos, you'll realize that the only way to do this is with lithium ion batteries - like the electric cars are doing. That is feasible now, as shown, it's just a matter of the cost. It's coming though.

[mastreb]

Why did he pick Group 24?

Previous owner picked them. He's figuring out exactly what he wants to do to upgrade the entire charging/monitoring/battery system.

[bartmac]

all you need is very long extension cord

[Divecoz]

I am in the same situation as well .. PO's and One is Me ... I have soooooooooo much on my plate right now with the total and fairly extensive remodel of this house.. Changing doors cutting in new doors gutting a bathroom and another bath rehab next winter.. Moving walls completely new kitchen $$$$$$Painting painting painting.. Inside and out.. !!
add 1800sq.ft. of 1/2" x 18x18 travertine..
I know what I would really like but $$$ and every change requires lots of work.. Like with the new S.S. Delta anchor I bought. Average lsit price was between $425 and $575
I looked and looked and my brother found a site 15.5 lbs for $239 so pull the trigger I did.. an hour later RussMT posted a site where a smaller one was half $ and 5lb. larger was only $5 more @#$%^&*( !!
If my new seawall boat lift and dock get in quickly? Sooner than later? I may for now , just live with what I have on both boats , at least for the summer..

Previous owner picked them. He's figuring out exactly what he wants to do to upgrade the entire charging/monitoring/battery system.

[Ixneigh]

I blasted my way up Hawks Channel in 20+ knots of headwinds. Insane but had to return home due to issues with work. No way your doing that in a hybrid. That means if you want to cruise the boat in anything but a mill pond that etec (or whatever) is going to stay on the transom regardless of whatever other motor you have.
Not to say a hybrid with a very long narrow hull with wind and solar battery chargers might not be able to cruise in mild weather. Forget about the macs. They were designed for big powerful engines. Unless you just need the motor for less then an hour, that is. If you only used it on the weekends, a wind generator could charge your batteries all week.
Ix