I though I would give the group a report on the results of my sailboat repower.
The boat is a 1976 model Pearson 35, ~13,000 lb displacement. Over the last 6 months I took out the old Westerbeke 25 HP diesel and re-powered with an ElectricYacht model 130ib. The battery pack is 48V, 8- Trojan T105s in series. Overall I'm pretty sure I took out more weight than I put back in because the stern sits higher in the water.
Today was the first chance I got to give the motor a real tryout. Motored about 6 miles on San Francisco Bay out of San Leandro..
Bottom and prop freshly scrubbed.
Conditions: light wind (5-8kt), smooth
water, sunny and clear. Slack tide.
At full throttle, the
monitor reports 113A / MotorLimit. GPS reports ~4.9 to 5.3 Kt.
70A: ~ 4.3Kt
50A: ~ 4.0 Kt
20A: ~ 3.0 Kt
Speeds were basically the same upwind and
downwind.
At 20A (My wife Katie: "Is it on? feels like we are
gliding.") , it is whisper quiet. At 30A we start to feel some
vibration (from the prop, hopefully), but even at full throttle it's
pretty quiet.
Overall I'm very happy with the performance.
With the old 25HP Westerbeke I seldom cruised above 5Kt because the
noise and vibration was so fierce.
The prop is an old 2-blade bronze, 14x11. We could upgrade to 72V for more power or range, and/or upgrade the prop to a newer model. But rather than invest any more, I plan to leave it like it is for now and do more sailing.
Regards,
Bob
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