Joseph, One Motor don't multiply.
Cheers, Al Lococo ----- Original Message ----- From: "Joseph T. " <[EMAIL PROTECTED]> To: "Al Lococo" <[EMAIL PROTECTED]>; "FLEAA Mailing List" <[email protected]> Sent: Saturday, June 21, 2008 1:06 PM Subject: Re: [FLEAA] In-Wheel Motors? > I'm not talking about the overall efficiency of an EV. That would be > very hard to calculate. > > What I meant was that with all other factors the same, what would be > more efficient to use, one motor or two motors? > > On 6/21/08, Al Lococo <[EMAIL PROTECTED]> wrote: >> Joseph, >> >> FWIW, I am not an engineer. >> >> I don't think you want to multiply efficiencies in this case. Both >> motors >> draw from the same source at their respective efficiencies. You should >> multiply the efficiency of the charger times the efficiency of the >> battery >> pack times the efficiency of the motor to get electrical efficiency. >> >> You also have mechanical efficiency of the drive train to take into >> account >> if you have one. If you are driving the wheels directly, you eliminate >> drive train efficiency losses and weight. >> >> There may be a decrease in efficiency of the battery pack with the load >> of >> two motors. You wouldn't calculate that by multiplying motor >> efficiencies. >> Check battery specs. >> >> The motors are probably slightly more than 90 percent efficient and the >> battery pack is probably about 90 percent efficient. Check your charger >> specs. >> >> Cheers, >> Al Lococo >> www.evprogress.org >> >> ----- Original Message ----- >> From: "Joseph T. " <[EMAIL PROTECTED]> >> To: <[email protected]> >> Sent: Saturday, June 21, 2008 12:58 AM >> Subject: [FLEAA] In-Wheel Motors? >> >> >> > I've always thought that one motor is more efficient than two because >> > if a motor is 90% efficient, when you have one, you'll have 90% >> > efficiency. On the other hand, if you have two, you would only have >> > 81% efficiency. (90% times 90%) Right? Is this correct? >> > >> > _______________________________________________ >> > Florida EAA mailing list >> > [email protected] >> > http://www.floridaeaa.org >> > >> > >> >> >> _______________________________________________ >> Florida EAA mailing list >> [email protected] >> http://www.floridaeaa.org >> > > _______________________________________________ Florida EAA mailing list [email protected] http://www.floridaeaa.org
