Sunday, September 14, 2008

Just passed 6000 miles and fixed PakTrakr Issues

Two quick updates for the 914 EV since I've started working on the Civic-EV:

First, I just passed 6000 EV miles and the car is still going strong.

Second, the PakTrakr system has been acting up and reporting battery failures. At first, this really worried me that my battery pack wasn't doing well. Many first-time EV builders burn out their pack early.

Upon further inspection, the PakTrakr was reporting failures on batteries that were adjacent to the fusible links in the rear battery box and the front battery box. I tried an experiment by moving the PakTrakr battery wire from one side of the fusible link to the other. This should have theoretically caused no change because the fusible link should have no resistance. I was a bit amused to find that the "failing" battery jumped to the battery attached to the opposite side of the fusible link.

This experiment tells me that the fusible link has enough resistance to confuse the PakTrakr into thinking that a battery is failing. It shouldn't be too surprising since 200 amps going through 10 milli-ohms will cause 2 volts of drop, indicating a bad battery. The bolts on the fusible link metal had loosened up a bit and I suspect they had corroded as well, since the "fuse" is a different metal than the copper bar. I added Noalox anti-corrosion compound to the ends of the "fuse" metal and tightened down the fuse bolts to hopefully fix the problem.

Until something else major comes up, most of my efforts will be over at the Civic-EV blog.

Cheers, Tim


Joe said...

Quick note: could you move the Honda URL link to the top of your URL list (Ross did). Sicne I often stop by the classic site on the way to the Honda site.

TimK said...

Good Idea. I just added it.

Cheers, Tim

JoeB said...

tim, would you send me a diagram for wiring up the iota dsl-45 to the relay board of a dc porsche conversion, i'm not understanding the instructions very well. i would appreciate the help. i have a few other requests if you would care to help with those also. i'll wait for a response. thanks

TimK said...

Hi Joe,

I have a picture of how I installed the DLS-45 here:

If you have the diagram for the original CCPower C400 DCDC, you just tie the two high voltage terminals to the two plug leads on the IOTA DLS-45. The out low-voltage connections go to the beefy screw terminals on the top side of the DLS-45. There wasn't much that changed in the circuit diagram. If you need additional help with your 914 conversion, please join the Google Group at:

I've found much help from the folks on that list.