As a rule I do not like to cross post between threads but I have to make an exception here because this information pertains to this thread as much or more as where it was
originally posted.
pro10is wrote:
walt wrote:
...There is one valuable peice of info that I think anyone considering electric would want and I see from a picture you posted that it would be very easy to get. I have posted this before.. maybe sometime someone can take the time and get these numbers.
The display in the picture posted gives both the boat speed in mph and watts being used (last two rows)
You may have noticed that battery capacity is specified in watt hours. Ie, 915 watt hours for the larger battery. How much actual capacity you get out of a battery is somewhat influenced by the rate you use the power but this should be a good indication of what range you get out of an electric motor.
For example, in that picture, the speed is 4.5 mph and the power being used is 273 watts. If you had the larger battery (915 wh), you can expect that at 273 watts, you would use up that 915 watt hours in 3.35 hours (simple math: 915 watt hours / 273 watts = 3.35 hours). At 4.5 mph, you would then go 15.1 miles (also simple math.. 4.5 mph * 3.35 hours - 15.1 miles).
Simple math involved here. no snake oil and exactly what I would want to know before buying electric as this result in not clouded by sail or pedal power. Add in all three at the same time you have no idea exactly what the electric contribution is.
So what would be interesting is to get the power vs speed readings for each of those electric motor setups. It would then be easy to compile a table showing what the range vs. speed would be for a given battery capacity.
Anyone with electric willing to get some simple data? Just note the power display for say 1 mph, 2 mph, 3 mph.. etc up until peak mph. Post results here.. it would be very interesting.
I'll start bringing a notebook with me and attempt to provide you with this data.
I apologize that this took so long, but it literally took all season to find a day were conditions were perfect enough to obtain this data without any other factors interfering. These numbers were taken on a day where there was virtually no wind, calm seas, and no water disturbances from other boats, as close to perfect as it ever gets.
1.0 MPH - 13 W
1.5 MPH - 31 W
2.0 MPH - 44 W
2.5 MPH - 66 W
3.0 MPH - 97 W
3.5 MPH - 155 W
4.0 MPH - 199 W
4.5 MPH - 296 W
5.0 MPH - 410 W
These values are the average of the data sets repeated ten times and are as accurate as possible given real world conditions.
Here is the data in chart form:
Using this data we can determine the Speed vs Run Time with each Torqeedo battery available for the 403: the 320 WH, the 533 WH, and the 915 WH.
And also the Speed vs Range for each battery.
Disclaimer: I'm ok with people using this as a general baseline, however I've mentioned many times before that these figures are theoretical only and that real world conditions can and will change them radically. If you were using the 403 in unfavorable conditions such as against a strong headwind and strong currents or waves, the results would decrease significantly. Whereas if you were in favorable conditions such as running with the wind, current, and waves, or using the sail or pedals along with the motor, the results would increase significantly. So please keep that in mind. Also you rarely travel at the same speed, at any time you may choose to go slower or faster.
If you own a 403 then you already know that the onboard computer will continually calculate your remaining run time and range in real time given the current power consumption, battery charge, and speed. This will be your most accurate data. If you don't own a 403 then you can use the charts above for a general idea of what to expect.