Does doubling the speed require 4 times the power?

[SAcharlie]

I've seen this many times. 2X speed = 4X power.

That woud work out like this:
Say 36V@[email protected] = 161Wh/mile then,

72V@112A@25mph = 323Wh/mile.

Now are they letting apples/oranges in that equation using different motors and adding more battery weight?

If ya run up a 36V motor capable of 72 volts for double the speed are the amps gonna double too even if the weight is the same?

 

[Gonzo]

Αυτό είναι όλα τα ελληνικά σε με. which means "This is all Greek to me in Greek.

 

[dougmcp]

2X speed (voltage) = 2X power (amperage) = 1/2 the time to cover the same distance.
So, what are you trying to accomplish?

 

[SAcharlie]

Yeah ya got 2X the power for 2X the speed so Wh/mile should be the same for that.

The statement often quoted is 2X the speed but it takes " 4X " the power.

Was wondering if this was a good DESIGN RULE when ya double the speed of a golfcart OR is that more for larger auto conversions and at higher speed than 25mph?

I even read where a Power Wheelchair engineer said that it taked 4X the power to double the speed... and he is talking about increasing from 6mph to 12mph.

I dunno know for sure if that is a Hard&Fast rule but it will make a big difference and would like to find out.

 

[dougmcp]

Do you have a cart? Are you buying a cart? What are your needs and what do you envision? Lifted, large tires, number of seats, terrain?