T-Pain Is On A Boat: Re: [Electric Boats] New Photos

Tuesday, February 8, 2011

Re: [Electric Boats] New Photos

Steve,

These are huge batteries on Kapowai that rarely see any great current. Typically, the boat operates at less than 40 amps, which is about 23 amps for the group of 8D's and 17 amps for the four 4D's, with my most common throttle setting for cruising is 8 amps total.

In hybrid situations where the boats are running at 2C, 3C or 4C then ventilation of the batteries and keeping them cool is an issue and securing foam should not be used. However at the low discharge rates that these batteries see, it is not a problem.

I like knowing that my batteries do not move. ABYC guidelines allow them to move an inch or two in either direction, which I disagree with. Batteries act as ballast, and this was an easy way of making them an integral part of the hull.

I will probably change the set up and find another way to keep them from moving - not because it doesn't work well in a setup for a boat like this - but because I don't want anyone using this technique if the ratio of their battery size to current is far different from mine, or if they are operating in higher ambient temperatures. Here in Santa Barbara the sea temp is in the 50's or 60's, the air temp is usually in the 60's or 70's and we rarely see temperatures in the 80's.

Regards,

James

On Feb 8, 2011, at 8:38 AM, Steve Dolan wrote:

James any issues with the "securing" foam causing heat to be maintained at the batteries? Proper ventilation at the battery casings is typically a must.

Steve in Solomons MD

Looks great James. Did you expand the galley counter to cover the controller? Do you have component cost numbers?

Mark
Santa Cruz

--- In electricboats@yahoogroups.com, "Doug" <dj2210@...> wrote:
>
> Looks great, James! Love the look of you C30. Do you have any performance numbers to show?
> Doug
>
> --- In electricboats@yahoogroups.com, "James" <james@> wrote:
> >
> > I just finished a project that completed the installation of our Propulsion Marine 5 KW High Thrust Drive Unit the way it would have been installed if it had been original equipment on a new sailboat. Additions included a 3 KW Inverter Charger with a 2 KW charging circuit and Mate Remote by Outback Power . We installed the inverter charger beneath the backrest of the Port Settee. The outback charges at 35 amps at 58 volts DC and gives complete control over absorption times, charge voltages, and after the batteries float, decouples from the batteries until the batteries reach a predetermined voltage at which time it runs through another charge cycle.
> >
> > We built a "tower" to house all the electronics and installed a Victron meter to manage the Battery - complete with a Peukert's exponent and time to go indication. We double walled the engine compartment making it very clean and made an additional glove box type area above the electric motor for storing sweaters etc.
> >
> > We also installed an Outback Flexnet DC monitor which monitors and counts kilowatt hours through three shunts so we will be able to get ratio of power used by the motor compared to the house, plus a sum total of all charging sources.
> >
> > We installed an electric fan and a relay that is controlled by Sevcon's Gen 4 controller to come on at a predetermined motor winding temperature. This enabled us to increase the output of the motor to 6KW after one hour of use. The motor was a little warm, but did not overheat. It was very interesting charting the motor temperature to time.
> >
> > We glued on teak plywood around the engine cavity, covering up the old engine inspection hatches. Inside the original fiberglass wall we added sound insulation. The electric drive now has a sweet, silky smooth hum that is barely noticeable at cruising speeds.
> >
> > We added a 48 volt DC distribution center complete with a 250 amp break under load breaker. All of our future kits will include this breaker box in addition to the isolation switches we currently provide. It cleans up the installation and provides for 3 surface mount breakers up to 100 amps and 5 din rail mount breakers from 1 to 63 amps. We are using the 3 surface mount breakers for the DC genset, the inverter charger and the solar array. We use the din mount breakers for gages, a future 48 volt windlass, and a new style of DC to DC converter with battery backup.
> >
> > We have accomplished a higher level of safety, power, reliability and aesthetics in a package that is quieter and takes up less room.
> >
> > The latest information on this boat can be viewed at www.electricboatdesign.com and the photo album on this group by the name of Propulsion Marine.
> >
> > Back to the boat now,
> >
> > James
> >
>

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