Re: I need help

[jcmassey@netspace.net.au]

At 12:56 30/11/01 +0000, you wrote:
>hi all
>I want to thank you for helping me
>I want to build a ev for three persons and run at 100 to 150 Km/hour.I
hope you give me motor and controller specifications
>
>thanks
>
>               Alex Benites 
>
>sorry for my english

Stop apologising for your English, it's fine. 

How far do you want to go per charge? If you do not want to go very far (25
to 30 km) a small vehicle such as the Volkswagen golf/rabbit or the
Japanese cars would be fine (4-seater). If you want to go 100km (60 miles)
per charge at 120km/h (70 miles per hour) then you are going to need a
small-to-medium sized 'pickup' truck (about 2 to 3 ton laden mass vehicle)
with a 3-seater bench seat. The smaller car will be a much cheaper
conversion, since the larger vehicle has bigger batteries, motor,
controller etc., that all cost more. You also need to define your top speed
better. At 150km/h you will get less than half the range you would at
100km/h (wind loading goes up by [I think] the 5th power of the velocity).

You have already started to define your vehicle, once you know how far you
need to go per charge you can then start to define the type of vehicle and
the approximate size of battery pack. Then you need to decide how fast you
want/need to climb hills (what your peak power needs are) and how many/how
steep these hills are. If you have a lot of long descents, regenerative
braking will be useful. These factors define your total power requirement
(total battery pack size in energy stored).  

So once you have got this far, you now will know approximately how heavy
the vehicle will be. This mass will need to be accelerated, so this
determines the motor power you will need to look at. Then you can define a
short-list of suitable motors and controllers. Then you look at the AC or
DC question, based on cost, features, fail-safe, etc. Then you decide the
low voltage/high voltage question, how quickly you need to recharge, and
define the battery charger.

If you go to the EV discussion list photo album  http://evalbum.com and
have a look at what other people have done with their conversions, it may
help you to decide on the type of vehicle.

James Massey