# Newbie: Setting up some "testbed", before building the actual car



## Yabert (Feb 7, 2010)

1- For similar voltage, no need to care about.
2- Right.
3- Some power supply can do this, but I suggest to you to find one or two cheap and used 12v battery to play with.


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## dtrip (Dec 12, 2012)

Thanks for your reply,

btw I saw your Smart project, great ! 
Are there cheaper controllers (say around $300) than the one you used ?
My project will require not more than 120 Amps (about 8 - 10 kW motor) 
I could bring it even lower to 100 Amps max. 
In case Amperage affects the price, that is. But I think it does. 

Most of the controllers I have found are rather overkill for my project. 
EDIT: Except these ones: would that be Ok for a small single seat electric trike ?
http://kellycontroller.com/pm72201200a72vwith-regen-p-301.html


Thanks again,
Dimitris


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## Ziggythewiz (May 16, 2010)

What's the goal of the project? If you want to program/test a controller, are you building one? 

Keep in mind most motors can't be tested too much unloaded...too much voltage they'll spin apart.


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## Caps18 (Jun 8, 2008)

Ziggythewiz said:


> What's the goal of the project? If you want to program/test a controller, are you building one?
> 
> Keep in mind most motors can't be tested too much unloaded...too much voltage they'll spin apart.



I would assume that like me, I would like to 'wire' everything up outside of the car to see that it all works before fitting it all together.

Or before spending $6000 on batteries or doing hours and hours of work to get everything 'right'...


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## dtrip (Dec 12, 2012)

Caps18 said:


> I would assume that like me, I would like to 'wire' everything up outside of the car to see that it all works before fitting it all together.
> 
> Or before spending $6000 on batteries or doing hours and hours of work to get everything 'right'...



Yes, exactly that. Wire everything outside the car. Buy Lithium batteries last. (I am also looking for a way to skip batteries completely initially and have the car "tethered" to the grid somehow). 

The goal of the project is to build a lightweight electric trike, single seat.


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## dtrip (Dec 12, 2012)

Ziggythewiz said:


> What's the goal of the project? If you want to program/test a controller, are you building one?
> 
> Keep in mind most motors can't be tested too much unloaded...too much voltage they'll spin apart.


Yes I know that. The project is to build a lightweight single seat vehicle. It will have a 6kWh battery pack and a forklift motor (about 8-9 kW at 72 Volt, drawing about 100+ something Amps. Not exactly sure because I have not found the motor yet) It should drive 30 miles with max speed 40 mph.


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## Yabert (Feb 7, 2010)

Important thing to know, motor amps will always be higher than battery amps. The difference is especially important in direct drive application.

The Kelly you show is only rated 80A continous. I think isn't enough for your application. 
Take a look at Alltrax controller.


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## dtrip (Dec 12, 2012)

Yabert said:


> Important thing to know, motor amps will always be higher than battery amps. The difference is especially important in direct drive application.
> 
> The Kelly you show is only rated 80A continous. I think isn't enough for your application.
> Take a look at Alltrax controller.



Oh you are right. It said 200Amps but it means peak (for 1 minute only). 
The next model of the series (300 Amps) has 120 Amps constant, so I suppose it is close to what I need. 

I looked at Alltrax, I have found a model that would suit me but mentions no price. But I guess it is Ok, I keep this for later, thank you ! 

Speaking of direct drive, do you think I could skip the gearbox completely in my project ? Vehicle weight is 500 lbs (without passenger), motor power is 8600 Watts, maximum speed is 40 mph (70 km/h) on level road. But will it be able to make a steep uphill start ? 
EDIT: Otherwise, I don't have any idea of how to squeeze a gearbox between the motor and the rear drive wheel (it will be a motorcycle wheel, the vehicle is a reverse trike)

A million thanks, this site is officially a partner in my project. 
I hope it goes well so that I can return the favor in the credits  
Dimitris


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## Caps18 (Jun 8, 2008)

http://www.youtube.com/watch?NR=1&feature=endscreen&v=dFWEc7Ytq44

The controller manufacturers should be making simple videos like this that show and explain how their product is wired up. Along with recommendations for the other small components that will work.


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