T-Pain Is On A Boat: [Electric Boats] Re: Greetings and introduction

Friday, August 14, 2009

[Electric Boats] Re: Greetings and introduction

Hi Eric,

Welcome. So... for "I would like enough thrust to power against wind and heavy seas" you already know the trick question - for how long? At max amps, my battery pack (345AH) is good for an hour. Even with a genset, it takes 4KW to push the boat hard (same weight as yours), and 4KW of charger/genset is pricey.

For a craft like yours I think you are correct that you'd want to go higher voltage. Alternately, I've seen some dual-motor setups - so a pair of brushed motors belted to the same shaft - but I don't know if anyone is doing them commercially. Sounds like you are handy though. That keeps your amps down, parts cheap and offers some redundancy.

With lithium batteries, you could potentially pack at least a couple of hours of runtime in, but at a steep initial price.

Regards,

-Keith

--- In electricboats@yahoogroups.com, "Eric" <ewdysar@...> wrote:
>
> Hi,
>
> I'm new to the group, but very familiar with electric car conversions. I own two boats, a 1990 Farrier F-27 trimaran and a 1964 Cheoy Lee Bermuda 30 ketch. The Cheoy Lee has issues with it's Yanmar SVE12 single cylinder diesel motor and I am trying to figure out a reasonable way to re-power her with electric drive.
>
> 15 years ago, I built a few electric conversions, a Pontiac Fiero, and 2 Porsche 914s. Looking at what is available today, there really hasn't been any revolutionary advances in drives, batteries or controllers since then.
>
> If I re-power with diesel, I'll probably go with a Yanmar YM15.
>
> The Cheoy Lee is full keel with a transom hung rudder (think Herreshoff H28) and weighs a little over 10,000 lbs. The prop is in an aperture between the keel and the rudder. I would like enough thrust to power against wind and heavy seas.
>
> I know that more volts equals less amps, but it looks like most marine systems are 48V. I'm OK with that if I can pull enough thrust without cooking my batteries and running cables bigger than my thumb.
>
> Anybody have some suggestions and results from this type of conversion?
>
> Thanks in advance for your help.
> Eric
>