Well we had a good outing last week and I have been going over my notes. The numbers are closer to what we originally were expecting. We have been hampered by the tach not working on the diesel but we have good data for trip management. We are still learning the boat and the system. We also placed second in our class 6 min adjusted speed behind a much newer 39 ft Pacific Seacraft (not so bad for a $2000 boat!).
Previous data was based on shorter runs off of the harbor. Moving up the coast with the diesel into a 1 plus current we charged the batteries to 95% (51.5v). We than drove the boat for 90 minutes under electric at 4.5knots drawing 40amps (that is the speed we seem to get good results (natural speed?). The batteries were brought down to about 40%. We than ran the diesel for 3 hours and recharged the batteries bringing then back up to about 95% (51.4). This is very close to what we were expecting in a more real life passage making. 2 hour diesel and 1 hour electric.
The small 15 hp Yanmar can only charge the batteries at about 1.2 kw at its highest rpm in best circumstances. We did not have enough power in the diesel to run it at that level and still make good passage at a reasonable 4.5knots. Our recharge was at .67kw while running the three hours at 4.5knots. We did a short test by reversing our course by 180 degrees and the speed of the boat increased to 5.5 and the recharge also increased to .9kw. Again this is they unique experience of this boat with with diesel and with this motor.
We also found out that we had certain parameters built into the system. When we put the diesel under full power, as in an emergency power up, the controller turns off the electric generation. Also at slow speeds as you might experience in and out of the slip, the controller again turns off the electric generation. This was programed into the system to allow the diesel while it is not running close to its power efficiency curve to not be burdened by the extra power needs of generating power.
If the hybrid electric were installed coupled with a more powerful diesel in a boat with a better speed through the water, the system could be programed to generate up to 7kw. This is absolutely a design effort by the propulsion engineer who is programing the electric motor and the boat owner needs within the limits of the boat.
My thinking is that we would also be better off to replace the three bladed prop with a two bladed prop. This would likely result in a reduced load to the diesel and should not reduce its efficiency too much while allowing the diesel to possibly drive the generator more effectively. Sometimes you just have to experiment.
Mike
Electric Yachts of Southern California
--- In electricboats@yahoogroups.com, "Mike Gunning" <mike@...> wrote:
>
> Looking at 10 to 12 miles range to 40% DOD, 25amp draw for two hours. We will be testing the battery pack and the systems this week with a trip to Long Beach and doing the Border Run 2 Race coming home. Small battery pack for a boat of this size.
> The sail plan is to only use electric in the harbor, day sailing, and adding speed for light wind days. The diesel will be used for passage making on a 50/50 basis when moving up the coast into slight current and normal head wind. One hour diesel and one hour electric. We may add some more battery power to 200AH as that would be a more normal battery bank for this boat and the motor. We have 150AH 12 volt on the boat and could remove that and install 4 more 100AH batteries with a step down charger.
> The plan is to add the clutch to the system later this year making the system chargeable at anchor.
> Mike
> Electric Yacht of Southern California
>
> --- In electricboats@yahoogroups.com, danbollinger <no_reply@> wrote:
> >
> > What kind of range to you expect in all electric mode?
> >
> > --- In electricboats@yahoogroups.com, "Mike Gunning" <mike@> wrote:
> > >
> > > I have posted pictures of my 1976 Columbia 9.6 Diesel Electric Hybrid demo boat.
> > >
> > > http://groups.yahoo.com/group/electricboats/photos/album/1469361680/pic/list
> > >
> > > The project included the installation of a rebuilt Yanmar 2QM15 of the same vintage. The boat had not moved from it slip for over 3 years and required a complete update of the interior but had great running and standing gear.
> > >
> > > The engine was mounted 6 inched forward with an extension of the shaft because the engine stringers were not in the right place for the motor. The initial sea trials performance of the system has been good. The diesel and electric both push the boat at hull speed. At 4.5 knots the diesel will run the electric in generator mode at 1.2kw and that is about 25amps at 48v. At 25amps the electric will push the boat at 4.5 knots. Seems just about right
> > >
> > > This is our 7.0 Weekender version without the clutch system. The boat has 100 AH AGM batteries with a QuickCharge SCO4825 (25 amp at 48v) charger.
> > >
> > > Mike Gunning
> > > Electric Yacht of Southern California
> > >
> >
>
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