New Contactor

So the car has been in the road for 4+ years and running relatively trouble free. In late November, though, it suddenly shut down on my way to work. I was able to pull over and restart it, but it was troubling. The Zilla error codes pointed to motor over speed, contactor stuck and low 12v supply - the usual hodgepodge of errors I see when the SLI battery is low.

I recharged the SLI battery over night but on the way to work the motor shut down again. It did restart and once I was home again I checked my wiring to the controller, thinking a loose 12v, ground or tach lead could be causing the problem. Everything looked Kosher. 

The next day on the way to work it shut down. I coasted off the freeway and parked. I tried restarting it, but this time instead of the familiar contactor "thump" I heard a sizzling sound. I pulled the pack emergency disconnect, pulled my meter from the glove box and made some quick tests. I quickly found that the contactor points had welded closed - which was probably the sizzling sound I heard.

I was using a Kilovac  EV200 contactor and though rated for up to 2,000 amps and can handle 500 amps at 320volts continuous. EV Source points out that these ratings are based on a very large cable size -300 MCM, which translates to about 4.5/0 where I am using 2/0. I was told the connector bolts would get warm from the resistance and ultimately weld shut (which they apparently did), but they never got warm to the touch in my typical drive ad never discolored to indicate overheating. Evidently the bolt temperature doesn't relate well to the contact temperature inside...

This is how the original EV200 contactor looked in the High Voltage Enclosure:

So naturally I wanted to upgrade to a contactor that wouldn't die on me again.  I looked at Nanfeng and Albright but ultimately decided on a Gigavac. The Tech Support at Gigavac said my 350 amp continuous at 170 volts was within spec for the GX14 as long as I used copper buss bars to dissipate any heat.  

The GX14 is larger than the EV200 has a lower cable connection point than the EV200. After going through numerous mounting plans, I came up with one that  used buss bars to connect the cable from above to the input bolt below and to the Ferraz/Shawmut fuse. 

This is how the Gigavac GX14 looks in the redesigned high Voltage Enclosure:

You can see the copper bus bar on the right middle under the 2/0 cable. The contactor is the black circular unit in the middle. The output of the contactor goes to a short bus bar into the Ferraz/Shawmut fuse positioned vertically. It's bolted to the output cable to the Controller.

dead battery

Well, haven't had much to post about in quite a while. Generally I come home, plug the car in and in the morning I unplug it and drive it to work. Simple as that.

Tonight it wasn't so simple...
It was a misty morning so I drove to work with my driving lights on - not the headlights, just the driving lights - it wasn't dark, or rainy just a little misty. So I park in the lot in plenty of time for my 9:00 meeting and at when I return to my car at 6:00 - nothin'. No dash lights, no familiar thump of the contactor, just nothin'. At first I wasn't sure what had happened, then I noticed that the light control was still on - the battery was dead. Without the 12v battery, the contactor won't close, the controller won't get operating voltage, nothing will work.

Now I sat for a minute and remembered something... When I first built the car I had the DC/DC converter connected directly to the pack, but it was constantly charging the battery and draining the pack, so I put in a relay so that the DC/DC converter was only active when the key was on. Now there was a small mechanical switch on the side of the relay that allowed you to activate it manually, I knew if I could get the relay to close, the DC/DC converter would provide the 12v needed to get the car to work.

I popped the hood and unscrewed the cover of the High Voltage Enclosure to access the relay, With a flash light I checked either side for the switch - there it was on the driver side - just below 2 high voltage leads. I   turned the ignition key on then dug a pen out of my laptop bag thinking it would safely flip the switch, but it wouldn't reach it. I thought about it for a minute, but I knew I had to use my finger to do this. I put my left hand behind my back (an old trick I learned from a TV repairman - you don't want to touch ground with your left hand when you get a jolt on your right and have the shock pass through your heart...) and with my right index finger reached between the wires and pushed the little plastic tab in.  It made a satisfying clack as the relay closed and the 12v from the DC/DC converter kept it that way.

I closed the hood and got behind the wheel. Everything looked normal now., As I turned the key into the start position I heard that familiar thump of the contactor and we were mobile.

It was dark and with the headlights on I knew eventually the 12v would drop pretty low and the controller wouldn't like it - maybe enough to stall out - so I took the streets home. Sure enough, about a mile from my door the "Check Engine" light came on solid but she continued to drive fine. I got her home and safely into the garage.

I can't think of another car that will start with a completely dead battery. I've compression started a lot of cars, but never with the battery completely dead. Even the old crank-start cars needed a battery for ignition, right? These electric cars are somethin' aint they?

Blame the potholes

Before you read the following post, you should know that I drive this car daily.
It may seem that this blog recently is nothing more than a list of  problems, but when the car works (which it does 99.9% of the time) there is nothing of any interest to post - "disconnected charge cable, backed out of garage, drove to work, drive home from work, connect charger cable..."

Yesterday I had a little trouble getting to work. Along the way my controller appeared to shut down - the Charge light went out and the Check Engine light went on plus, I had no power. I coasted to a stop and restarted the car. Everything worked fine. I took the streets to work in case it decided to fail on me again and once I parked at work, I hooked up my laptop to my Zilla to read the error codes. There were 3 of them - the 12v supply was too low, the contactor opened unexpectedly, the motor RPM was too high. Sounded pretty serious, but I remembered a similar set of errors when my 12v SLI battery failed and I had left the door ajar one night, leaving the interior lights lit for 14 hours... I decided the SLI battery was to blame and after work, took the streets home without incident. Once back home, I hooked up my 12v charger to my SLI battery. It showed it was at 100% - but I ran it through a charging cycle anyway.

Next day, I drive to work without incident. Ont the way home, however, it stalled, First on the freeway (i was able to coast down the next exit where I was able to restart it), then at a left turn (sorry to the people behind me) then at a traffic light (more sorries to those behind me).

I figured it must be a loose 12v wire. Saturday I popped the hood and poked around for a loose wire. Everything looked fine...until I noticed the ground connection under the relay box was loose. I tightened it up and took her for a test drive - all good. A simple fix to what sounded like a serious problem.

The potholes must have rattled it loose.

First trip behind a tow truck ; (

(EV
Things had been going real well lately, so something was bound to go wrong...

I was on my way to work this morning - I had just shifted into 3rd at 55mph when the battery light went out and the check engine light turned on. This meant the controller had turned itself off with an error. Since I had no power, I coasted to a stop by the curb in a nearly legal parking place.

I tried to start it a couple of times without any luck. I then pulled out my laptop to see the error code from the Zilla, and it indicated the Zilla and the Hairball weren't communicating. I checked the data cable and it was in place and properly seated.

It took about an hour for the tow truck to come.

I contacted the vendor I got the Zilla from (EV Source) and they contacted Cafe Electric who after a few questions sent me an RMA number for the Zilla and Hairball.

Good news is it's not something I did, but the car will be out of commission for a bit.
; (