Car revamp-Controller move question

Ziggythewiz said:

Adverse effects are certain. Your resistance would increase by a factor of 4 (assuming current length = 2' and planned length = 8'). How that effect affects your performance is much less certain, but to completely offset the increased length would require your wire crosssection to also increase by a factor of 4, do they make 8/0?

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Zig,

Don't be ridiculous. Yeah, I'm sure they make an equivalent to 8/0. But get real. Figure the watts lost due to cable resistance and you are telling this guy to put an extra 10-20 pounds of copper aboard to save a few watts. Chances are he was oversize on the 2/0 he is presently using.

ZAND,

Your 2/0 should be just fine if you're under 230A average current. Zig is correct that increased length of cable does increase the resistance. But it is a pretty small power loss. Other than that, it will also increase the inductance, which is not a problem between the controller and motor. I'd keep the two cables adjacent to each other to minimized RFI.

Regards,

major

I wasn't trying to say 8/0 was necessary, just that you couldn't realistically increase the gauge to compensate for a relatively large change in length. Also, you couldn't make such a modification expecting no adverse effects whatsoever. As I said, the performance impact of separating the motor and controller is much harder to calculate than just the simple resistance involved. The resistance may not be a significant factor, but it would be similar to running your motor/controller config as they are now off a 5 gauge wire (or 3 10 guages) instead of the 2/0, which isn't something I would want to do.

I haven't seen any conversions (not to say they aren't out there) that have significant motor/controller separation, so I don't know if there's any real-world data out there.

The simple thing would be to test it out with a quick mounting and a test run to see if your performance or the wire temps are affected.