Friday, July 17, 2009

CivicConversion: More Tweaking

This week was spent gathering more EV driving data by my dad. I adjusted the vacuum switch on the brake pump because the pump would not turn off. A quick adjust of the setting screw and it now stays off for a lot less of time, but still works just fine.I also took another crack at figuring out the whole hill thing. I temporarily hooked up my current meter and took some AMP testings and then went off to the hill with the worst grade (5.6 %) and did a few runs, with momentum and one starting from a stop, after getting the controller warm.I found that it would draw 200+ amps, then drop down to 182 AMPs and wouldn't go any higher, even if I floored it. This means that the controller is limiting the current due to heat.So I found the most powerful CPU fan I could find and planted it on the Kelly controller. Man, what a difference! I have a heatsink for the bottom of the controller, but the top also needed some cooling. After a 5 mile run the controller was practically cold and usually it's quite warm. And it's 85 degrees F out today, and humid and it's probably closer to 120F under the hood and the controller will start to slow down at 125 F. The CPU fan was designed to cool Quad Core Xeon processors, so cooling the Kelly isn't too far out of it's design specs. And I can always add another one.Now it has to go through some real testing but my dad driving it to work again and see if it's any better. The motor needs to see 215+ AMPs to hold the hills at 30 MPH, which means it needs to pull 215 from the batteries, which hopefully it can do now for longer than a few seconds. 20-30 seconds would be nice just to clear the hills.

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