Power Consumption Speed and Range
"How far will the harbour launch go and how long will it
last?"
The chart and graphs below illustrates the important relationship between
speed and range. The principles at work here are not unique to
electric boats, but are common to all displacement hulls from row boats
to freighters. Studying these figures, you will see that the
boat uses very little energy traveling at low speeds and that the
rate of energy consumption increases substantially as the boat reaches
its maximum speed (hull speed). As well, the boat's range decreases
substantially as speed increases. Viewing the last three lines
of the chart (or the end of the graphs) you will note that the boat
will use 30% of it's power, consuming a full 10 amps, to accelerate
from 4.2 to 4.5 Knots. This 0.3 Knot advantage can be a very inefficient
use of power reserves. On the other hand, at the slower end of
the
scale, the
same 10 amps can push the launch at 3.3 Knots for 11 hours.
So...How far will the Launch go? Anywhere from 16 to 110 nautical miles.
How Long will a charge last? Anywhere from 3.5 to 110 hours.
Note: 1 Knot
= 1.85 KMH and 1 Knot = 1.15 MPH
