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Tesla Battery Terminal & Cable Overheating Issue

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Hi Guys,

This is my first post I've been lurking around the forums now and then for the last year or so to find useful information. I'm glad this site exists and I admire everyone here for their innovative thinking. I'm sorry that my first post will be to ask for help, and I will be grateful to anyone who can give me some insight to my problem.

I recently converted a 98 Porsche Boxster 986 to electric using 4 Tesla batteries, an AC motor and Curtis 1238 controller, etc.

Yesterday I was test driving it and after a few minutes I pulled over to inspect everything and I noticed that the terminals got extremely hot - hot enough to partially melt the plastic battery cover. Also my main contactor- relay eventually burned out and got so hot that it melted the plastic on some of the small accessory wires hooked to it (6mm dc/dc converter power wire, wire to charger).

I'm using standard 70mm^2 power cables. I know the cables are not the issue. But due to the angle of the battery box, I used a stack of large washers to raise the contact for the cable connection.

My question is, what are the main sources of this type of occurance? Bad contact? The washers? Anyone experienced something like this before?

Thanks in advance to anyone who can help me figure this out before I end up with a burnt and crispy Boxster. :)