TWO MOTORS OR ONE???

[svt/r&d]

OK Phase two oF my 100mph+ three wheeler Thanks for the responces on the tire issue, now i am choosing the power plants the total weight of the car is around 900lbs batts and all i am thinking two motors because there is really not much added weight at all compared to to overall car, i might luck out on some hi-pa motors which would solve alot of problems but if not, i am thinking a bank of batts for one motor and a bank for the 2nd motor once a bank runs down you switch to the 2nd bank or you could run both motors at one time for Turbo boost! lol

 

[Drunkskunk]

I guess it realy depends on your overall design, weight, power requirements, and so forth.

 

[fechter]

Two motors doubles the continuous power rating.
Also doubles the motor and controller cost (unless you're using brushed motors).

It usually works best to have a single battery pack run both motors. Lower C rate for discharge. You won't save much (if any) energy turning off one motor. Two packs running two motors all the time would be the same as one big pack running both motors, so if you wanted some redundancy in case of failure, this might be good.

 

[jondoh]

ONE!

 

[TylerDurden]

TWO!!

 

[Drunkskunk]

THREE!! AH HA HA HA

 

[D-Man]

I remember a guy on the other forum who had a lot of money and experimented with heinzmans hub motors and said that after he experimented, he concluded that having 2 motors front and rear was a complete waste of time. I don't remember if they were geared hubs or not but probably.

The way I see it is like 2wd vs 4wd cars. On road vs. off road-(snow/mud).

 

[Link]

Heinzmanns are geared.

 

[safe]

The reason for two motors is that at lower voltage you can get higher efficiency and better overall power. The down side is that you double the weight.

The better solution is to increase the voltage... but then that can cause overheating so you then need to use armature current limiting. This destroys your low end torque, so you then need gears...

It's a little like being a rat in a maze... you eventually end up at the one exit that makes sense... :lol:

 

[svt/r&d]

ok let me be more clear the cycle will be less than 800lbs even with two motors and the extra weight, less than 600lbs with a123s we will start out at 48volts one 10hp motor we estm will take the cycle car to 80+mph one motor will be idile, when bank 1 runs down or if motor 1 gets two hot you switch to motor 2 and bank two, we hope for a 100mile range with each bank.

a small gen can be added later to charge the offline bank

 

[Link]

You'd be better off running both at the same time. They'll be sharing half the amperage (and we all know about the exponential relationship between amps and heat) so they'll stay cool all the time (slightly higher efficiency because of cooler windings and magnets) and the brushes will last longer (they wear faster the more amperage is forced through them).

 

[svt/r&d]

the systems will not share banks or other controls totally independent from each other only in Turbo mode will they be linked when one is running the other is off

 

[svt/r&d]

a reminder one motor is more than enough to meet or goals with no stress on the system, the 2nd would be for super car takeoffs and ultra highway speeds if needed or a backup for some unlikly motor issue

 

[Drunkskunk]

The most efficent use is one motor, one bank. Breaking it into two banks with 2 motors is less efficent for a lot of reasosn.

From a design persspective, the only reasons to use 2 motors are (a) drivetrainless traction on steerable wheels
(b) the don't make a motor in the size you need.
(c) Hub motors on parralel wheels.
(d) compensating for small equipment.

The only good reason for 2 banks is... Well, there realy isn't a good reason from a design perspective for independant banks. Tieing them all together will give an efficancy boost, make them run cooler, and seriously extend there cycle life.

 

[TylerDurden]

Carrying the extra weight is well... a drag.

If you want boost: wire your pack to run in parallel for range, series for turbo.

 

[fechter]

ok let me be more clear the cycle will be less than 800lbs even with two motors and the extra weight, less than 600lbs with a123s we will start out at 48volts one 10hp motor we estm will take the cycle car to 80+mph one motor will be idile, when bank 1 runs down or if motor 1 gets two hot you switch to motor 2 and bank two, we hope for a 100mile range with each bank.

a small gen can be added later to charge the offline bank

That's going to be a huge pile of A123's!

 

[svt/r&d]

we want to stay with lead acid or amg so if we mass build the units will be under 11k but we can offer a123 if needed

 

[Deafscooter]

Deafscooter Read your Topic

This is Craig here

Deafscooter have Twin Motor ( one motor per wheel ) on Many Years of Build off e-Bike & Scooter

Here is Crusin speed is 20 Mph and Peak speed is 52 Mph ( Deafscooter rider on limo scooter )

 

[Link]

It might help if we could, mebbe, actually SEE the motors, methinks. :?