Archive for October, 2010

Replacement Power Cables

Wednesday, October 13th, 2010

I’ve just ordered new power cables.  The kit from EA provided 2 gauge cables – those are undersized for this project (big surprise there).  I’m ordering 2/0 gauge cables from  They have cables that are suitable for vehicles up in Alaska – should do just fine in San Diego.  🙂

Ground Fault with Battery Pack

Tuesday, October 12th, 2010

Well, I can’t say I wasn’t warned.  The Azure Dynamics controller was complaining quite a bit about a ground fault, and *some* GFCI outlets kept tripping.  I guess I was willfully ignoring the problem.

The problem was brought to the foreground, as the home outlet decide to start complaining when I was charging at 6A.  Not a good thing, and I didn’t want to start charging on non-GFCI outlets.

I consulted with a friend at work that just happens to know power supplies VERY well, and has a personal scope.  I brought the car over, and we looked at the power going in and out of the charger.  LOTS of noise on the ground line – on the order of 0.5A peak-to-peak at 50khz.  Enough to trip a normal GFCI.  Ok, so it is time to isolate the problem.

The kind people on the EVDL list ( brought my attention to ground faults in the pack.  Following this lead, I did some careful measurements and discovered that the high-power DC lines from the pack are leaking voltage to the car body.  *sigh*

So, assuming that the cables are indeed the culprit, I need to replace them with something that can withstand 370v DC and 200A.  Yup, gonna be fun.

At the very least, I get to move the power lines to different tubes from the control cables.