RE: [Electric Boats] new member and, of course, questions

Helo Reino,

Thanks for your quick responce.

I am aware that increasing the speed would mean a lot less range. But that is not that big a problem for me. As I said I'm living at a river which has only two ways to go, upstream and downstream. I use the boat only as a recreational boat.
Problem is that when I go under bridges the river gets less wider and the stream gets tougher, hence the fact I have problem getting forward.

I'm figuring that going downstream will not cost that much power, so there I win some.

What do you mean by "hull speed limited"? I tried to calculate the hull speed: 4,54 x

–4.1m= 9,19 km per hour. But the boat is definitly not going that speed. Well maybe downstream, but I'm not sure.

I am more considered about the heat of the motor, and the speed I now get with the 300 w motor. It's more a thing that I want to have some power extra in case of circumstances, like getting under bridges. I really like the slow flowing of electric boating, so thats not it.

Is there some info on where to buy these kind of motors? I have discovered that in europe the electric propulsion of vehicles is tsill not that big, the motors I see are i n the usa or china...


Thanks in advance,
Roland Kruijer

To: electricboats@yahoogroups.com
From: reino.urala@gmail.com
Date: Tue, 30 Jun 2009 08:47:54 +0300
Subject: Re: [Electric Boats] new member and, of course, questions

Hi Roland,
Reino Urala from Finland
Right now testing an el-boat with about similar battery capacity (4kWh).
Some measured reference data:
speed 4knots, range 50km, 350W
speed 8knots, range 15km, 2200W
speed 12knots, range 8km, 6000W
But this is a trimaran with small "hull speed effect"!
Note1: Increasing power means decreasing range dramatically.
Note2: Your boat is strongly "hull speed limited", and increasing power
would be much more fatal concerning speed and max. range!
Note3: A low wave drag el-boat is peculiar: You may make hundreds of km
by cruising really slowly. And you may make 15kn for short sprints.

redu

Roland Kruijer wrote:
> Hello Group,
>
> My name is Roland Kruijer and I'm from The Netherlands.
>
> I'm just entering the electric community as I bought an electric boat just a couple of weeks ago. http://www.electraboat.com/
>
> Maybe some of you know this boat or have one. I'm having a little problem with the speed of the boat. I allready changed the pulleys but as a result, the motor becomes hot, so I'm figuring that is not the way to do it. It now has a 300 Watt, 24 V electric motor which would be sufficient in a pond, but I live by a slow streaming river, there for the motor is too weak. Oh, and the batteries are 2 x 12 V 200 amp in series.
> Now, I'm searching for a replacement (bigger) motor to use. Also I read there's need for a controller?? and I'm also looking for a throttle of some kind, because the boat now only has on/off switch.
>
> I saw on the net that there are lots of electric scootermotors for sale, can these be used?
> What kind of motor should I use? The boat doesn't have to be a speedboat.
> Is it possible to use an ordinary electric motor, but instead of the 300w one with 600 or 900 watt?
> I'm a bit concerned about the power of the batteries going straight to the motor. The orriginal set-up got the motor handwarm, but since I changed the pulley, its becomming, well, hotter.
>
>
> As I said, I'm just entering this electric world and do not have experience in electronics. I'm more an automotive guy, so any advice would be great!
>
>
> Thanks in advance,
> Roland Kruijer
>
>
>
>
> ------------------------------------
>
> Yahoo! Groups Links
>
>
>
>
>

_________________________________________________________________
Nieuws, entertainment en de laatste roddels. Je vind het op MSN.nl!
http://nl.msn.com/

[Non-text portions of this message have been removed]

------------------------------------

Yahoo! Groups Links

<*> To visit your group on the web, go to:
http://groups.yahoo.com/group/electricboats/

<*> Your email settings:
Individual Email | Traditional

<*> To change settings online go to:
http://groups.yahoo.com/group/electricboats/join
(Yahoo! ID required)

<*> To change settings via email:
mailto:electricboats-digest@yahoogroups.com
mailto:electricboats-fullfeatured@yahoogroups.com

<*> To unsubscribe from this group, send an email to:
electricboats-unsubscribe@yahoogroups.com

<*> Your use of Yahoo! Groups is subject to:
http://docs.yahoo.com/info/terms/