# Unlimited Budget Build?



## JohninCR (May 6, 2008)

The biggest issue is 80mph. Batteries and their management system will be everything, so just go with the best and use A123's. Also, spend some significant effort on aerodynamics, because at 80mph it is a huge impact.

Start with how much power you need for 80mph. I don't know what that is, but for example's sake let's call it 50hp. That's over 37,000 watts. Assuming an 80% efficiency of conversion to mechanical power, you'd need batteries to deliver 45,000 watts of electricity. At 72v that's 625 amps. The little A123 M1 cells at only 70 grams each can deliver 70 amps continuously, so you'd need cells 9 parallel by 22 series to put out 50hp at 72v.

You'll have no problem fitting and carrying those 198 cells that weigh only about 30lbs, but they represent only 1500 watt hours of storage capacity, and to go 20 miles you'd need to use only 75wh/mile. I don't think that's realistic without very conservative riding, so with an unlimited budget, I'd at least double that if not triple it.

That's my 2 cents...center the whole project around your batteries and the battery management system, because they'll be the most expensive and critical part of the build. The motor and controller are almost an afterthought by comparison.

John


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## jorhyne (Aug 20, 2008)

If money really is no object, an AC motor would be a better option. EMS sells a nice set here: http://www.electricmotorsport.com/store/ems_ev_parts_motors_ac-induction.php


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## Bowser330 (Jun 15, 2008)

I am a bit concerned about the claims being made about the power in those smallish looking AC motors...I have heard that they will burn out if run that hot...does anyone else have information on these?


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