Quote:
Originally Posted by 75Sv1
It is what is claimed for brushless motors. Cobalt motors at claimed at above 80%.
Tom
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meh, might as well claim that my hydraulic transmission is 95% efficient, it is meaningless unless you take the system as a whole, that means....
- MEAN efficiency of electric motor, likely to be around 50% for any motor with a peak efficiency of 80%
- MEAN efficiency of control circuitry, usually around 85%
- MEAN efficiency of battery on discharge cycle, 50% if you are lucky.
Resulting on an overall efficiency of 21.25%
You STILL have issues with aerodynamic drag and rolling resistance.
You ALSO have the downside of the mass of batteries you are toting around, which weigh the same discharged as fully charged, with an energy density of approx 150 watt hours per kilogramme... you get...
4 kilogrammes of battery per mile travelled, so a 100 mile range = 400 kilogrammes of battery.
while the diesel car will do 100 miles on 4 kg of diesel.
100 kg is 7.5% of the weight of a small/average vehicle kerb weight, which therefore represents 7.5% of rolling resistance, which, due to the nature of the battery, IS ALWAYS THERE.