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Exide Orbitals are quicker than Optimas?

By Otmar
January 27, 2004

Hello All,

I must admit I had my doubts about drag racing at Vegas in January.

What was Rod thinking?
EV's don't do that well in the cold and the chance of rain seemed high. But hey, TV crews would be on hand and this could help get the word out to the public about EV's. You gotta do what you gotta do, so I committed to going if I could find a way to get my Porsche 914 "California Poppy" to the races.

The last time I raced in Vegas I resolved never again to flat tow the 914 for out of state events. I feel it's just too hard on the car. Unfortunately my stretch VW is not really strong enough to tow the Porsche plus a trailer so I was looking for a ride. Brian Hall of Thunderstruck Motors came through by offering to tow the Porsche there with his Bio Diesel powered truck and enclosed trailer. Could I ask for more? A enclosed trailer pulled by a CO2 neutral source, Sweet! In exchange I was happy to let him run the Poppy down the track.

Now I had to decide what to do to prepare the car.

I was hoping to tell the story of the Green Car documentary before this, but I've been busy and it has relevance to this race. So here it is now.
Flashback, a little recent history:

In November last year I was contacted by a film crew from Australia that was filming a Green Car documentary for National Geographic. Clare Bell had suggested that they might want to see California Poppy in action. They were hoping to show that green cars can be fun. They were trying to dispel the image of the nerdy idealists giving up fun and comfort just to drive green. (Hum, Then why were they talking to me?) They wanted tire smoke, burnouts, donuts in the parking lot, and wicked stop light acceleration. They wanted it all on Saturday which was only a week away.

Normally I would be happy to help them out, but California Poppy had a problem. The batteries were not up to it. The Optima Yellow Tops had performed well considering they had just been though 3 years of serious abuse. I never did  get regulators on them. They had been testing Zilla's which is not a easy job for any battery, they had to put up with my regular around town driving which is probably even worse for them, and once I had accidentally let them drain to below 6 volts each when I was gone for two weeks. For those three years and 4000 miles, the only charger that they had was a variac with a timer on it. It was time for new batteries.

John Wayland (aka Plasma Boy) had just been raving about the Orbitals on the list, Rich had tested one to 1800 amps, and it seems Sparrow drivers were getting good life out of them. The long life may be partially due to the fact that the Orbitals have each cell sealed in a compartment of its own with a pressure relief valve for each cell. Or it could be just that they were being treated nicely. Overall I figured they were worth a shot. But new batteries are not cheap, and I hadn't budgeted this. I figured I'd see how lucky I could get.

One of the wonderful things about the EV racing community is how we help each other out. In the past when Plasma Boy was in a bind I was there to help him out, so I figured I'd see if he might be able to help me out here. John did not let me down. He dropped everything, worked his contacts, wrote some glowing emails, and before I knew it the super folks at Exide were sponsoring me with a new set of Exide Orbital Marine deep cycle batteries. Thanks John! Meanwhile, while waiting for those I was cranking on a fresh Z2K controller for the Madman Rudman, and he was shipping me a fresh PFC 30 so I can take a little better care of these new batteries.

I was eager to get the Orbitals in the car for the documentary, and so had neglected to do some real basic research like checking the height. In the rear I have two layers deep of eight batteries each. When I dropped the first battery in I had that sinking feeling that usually prefaces a lot of work. The Orbitals were 3/8" taller than the Optimas. The racks were not tall enough. I spent much of the next three days with the help of Jos Goble remaking the battery racks to hold the extra height of the Orbitals. Despite the extra work, there was still time to wash the car and put a couple cycles on the batteries before the abuse was to begin. For break in I ran only 800 amps in order to be nice to them.

Saturday morning sunrise found myself, Clare, and three people making up the film crew gathered outside my house. They followed me to a parking lot a mile away where we had permission to do some filming. On the way there I was driving rather carefully in order to save battery power for the show. We pulled in and while the others unloaded gear the director came up to talk to me in the car. "Could you just do a small burnout here so we can get a idea for what we are filming here?" He asked. I thought he might be a little concerned with my tepid driving on the way over there and I couldn't quite read his expression. I said that yes, that would be no problem. With him standing right next to the drivers door I punched it and released full Zilla power backed by fresh Exide Orbitals into those cold Eco Contact tires. Of course they instantly spun up and spewed smoke. I hooked the car around to the left and then fish tailed off in the opposite direction leaving two wavy black lines of rubber on the pavement.

When I returned to the director his expression had changed considerably. He was all smiles and enthusiasm. Could I do exactly that again but heading right toward the cameraman? Aww shucks, I guess I could. :-)

We spent the day filming the Poppy, doing interviews and some road shots. All the while, between shoots Rudmans PFC 30 was keeping the batteries topped up. The film crew were a bit surprised that it only took an hour for the car to be topped up and ready for more filming.

So anyway, that's how the Porsche got a pack of Orbital batteries installed...
Now back to preparations for the Vegas race:

I had been running a couple of months on the new Orbital batteries. Shortly after the Green Car documentary I had to give up the last of my Z2K controllers for the Gone Postal project. I was stuck with a Z1K and only 1000 amps so I couldn't get a good feel for how they would perform relative to Optimas. This was probably good as it gave the Orbitals more time to break in at light load. But it would never do for racing.

I was building a batch of Z1K controllers for orders that were waiting so I added a couple Z2Ks to the run. By Tuesday before the races I had Z2K in the car ready to test. Driving was fun again! Punching the accelerator gave that familiar amusement park style surreal acceleration. But was it faster? I couldn't tell. It had been so long since I drove a Z2K on Optimas that I couldn't accurately judge how these compared. They felt faster, but I wasn't sure if I remembered correctly how it used to be. I decided that I would limit my changes for this race to only the batteries. I had changed to a thicker transmission oil since the last record setting run, but other than that the car was the same.

I spent Wednesday, the last day of preparations, washing the car and getting custom decals to advertise the Zilla controllers.  Then I figured I should drive the batteries real hard to warm them up and adjust the under-voltage cutback for peak power. I turned them up to 1800 amps and started putting cycles on them. After about 6 miles the batteries were sagging and the brakes smoking. The batteries were warming up nicely.

It was late on the third cycle when I was accelerating at full throttle down the expressway that the controller shut off. The check engine light was glaring at me as I coasted to the side of the road. This is good, at least it knew what was wrong. I put on my flashers and pulled out the Palm Pilot to see what the controller was complaining about. It said 1122, which translates into the IGBT desaturation detect has been tripped. This indicates that something caused the controller to put out a pulse of around 10,000 Amps! That was unexpected, and could be rather serious. I had visions of a blown controller just hours before the car needed to be loaded on the trailer for the trip south. As I opened the hood I sniffed for burnt silicon, but instead only smelled warm cables, then I saw what happened. There was a short section of 2/0 cables on the motor side of the controller which had been getting hot during dummy load testing, but never while driving. It seems that the Orbitals and hard driving were too much for it and the insulation melted allowing the cables to short the controller just inches from the case. I untwisted the cables to put some air between them and restarted the controller. It came up and ran fine. Whew! That was the test I was always afraid to do, a full power short circuit on the output. There's no guarantee that it will always survive it, but at least it worked this time.

Thursday morning I replaced the cable with 4/0 and tossed the burnt piece in the trunk to show off at the races. Brian Hall and Rick showed up to pick up the Porsche and it was on it's way.

Friday was spent driving, Jos (my chief solder boy) and I took the Insight to Vegas. People rarely talk about how low the gas mileage really is on an Insight in left lane traffic. I only get 53.3 mpg. Of course most of the trip is spent at over 80 mph. :-) Somewhere just before Vegas we saw a red RX-7 on a trailer, sure enough as we pulled up we saw it was Rich Brown Towing the Dualin 7 to the race. I was happy to see he was on the way too.

We pulled into the Nellis super 8 shortly after Brian and Rick got there. One of my fond memories of previous Vegas races is taking the Porsche out on the city streets before the races. So we decided to use it for running around town. First I wanted to make sure that I could charge when I got back. I unrolled my 120V adaptor cord and plugged it into the Hotel AC outlet. I hadn't even plugged the other end into the car when the breaker tripped and all the room lights went dark. Oops! I quickly rolled up the cable. Fortunately there was a maintenance guy working near the utility room which had all the breakers.  After some research and embarrassed mumbling about a bad plug that I probably shouldn't have used I figured out which of the several hundred breakers was for my room. I didn't just want to reset all the tripped ones as there were at least 5 of those per panel and 4 panels. I did see that they were all 30A breakers, so once I fixed the short in my cord I didn't hesitate charging at conservative 12A AC. With charging arranged the four of us took the 914 and my Insight over to Richard Furnisses house where Gone Postal was being rebuilt again.

I'll leave the Gone Postal story for others to describe, but suffice to say that it had that cool tired late night feeling with drag bikes and cars being charged and repaired. Occasionally there was the whine of a EV sucking a lot of amps and you could just make out a drag bike with no lights zipping down the residential road under the streetlights.

I decided that more Pizza was in order, so after filling the pack again I took Richard for a bit of a joy ride in the Poppy to the local pizza place. I think it was a 2.6 mile round trip and I used about 8 amp hours at 240V. We had fun! :)

While I'm thinking of it, I want to thank Richard, Kay and the whole Las Vegas gang for the warm hospitality even when it was way past bedtime and for arranging the generator and anything else which I've forgotten at the moment. They were essential to making the race such a great event.

Saturday, after breakfast we headed out to the track. I drove the poppy in order to warm up the batteries some more. Along the way some of the Sucking amps crew thought that they would give me a run for the money from the traffic light in a sedan full of four people. They made a nice effort but didn't stand a chance of keeping up. I backed off at 90 since I don't like to double the speed limit even if it was a big wide empty street.

It was probably almost 9am when we got to the track. I hooked up the spider box to the huge generator and pumped the lost joules back into the moderately cold Orbitals.

Tech inspection was pretty uneventful, thanks in part to the battery hold down brackets that Jos kindly made before we left. They tell me that there is a new rule in the 2004 NHRA rulebook for EVs on the track. They want a red triangle shaped light that is lit whenever the car is hot. It should be near the emergency off switch on the back of the vehicle. They also want the ON and OFF labels to be red. Sounds good to me. It would be best to confirm this with the rulebook as this is only how it was explained to me.

As for getting down the track my timing couldn't have been much worse. We waited in line for about two hours to get the first run. I set the car up for 1600 Amps in series mode and not expecting much took the first run. I was experimenting with controller settings and so didn't get a burn out, but no worries, I was just warming it up and getting the first slow run out of the way. It pulled pretty hard, and seemed to pull much harder near the end of the track than it used to.

When I picked up the slip for that first run it read 14.088 seconds at 97.30 Mph.

Hmmm, that was pretty quick. My last personal best was 14.399 at 93.47 Mph. At the time (11/2/02 at Sacramento) it was a record. And it stayed a record until Plasma Boy took it away recently with his 216V Orbital powered White Zombie. Grrr :-)  I actually didn't remember what his new record was. 13 something, maybe 13.7 or so, I just knew it was way out of my reach. After all, his car is not a convertible, is older and so is much lighter.

I wasn't really in a competitive mood anyway, so I let Brian Hall take it out and play. Brian came back with a big smile on his face. When I asked him how he liked it he said "That was a Rush!" (I think he may be building a car soon :-)
Brian bettered my time with a 14.019 at 98.57 Mph. He then ran again with a 13.940 at 99.22 Mph.

Wow! We got in the 13s! I had not expected this. Also the car was running very close to that 100 mph barrier. So far no electric street car has hit 100 mph in the quarter. Brian was just 0.78 mph away from it!

By now it was getting late. Brian offered for me to take the last run so off I went. As I was leaving the pits, Seth wanted a burnout clip so I stomped on it. The tires didn't even spin! Hmm, that's odd. While waiting in line to run I checked over the settings. Brian's first run was set the same as mine at 1600 motor amps in series, the full 2000 in parallel and 1800 battery amps with the battery undervoltage set to about 6.5V per 12V battery. For the second run I thought I turned it up to 1800 series amps but now that the tires wouldn't even break loose in the parking lot I suspected something was wrong. Sure enough I had turned up the "Normal" settings to 1800 but the "Valet" settings were only 1600 Amps. I had accidentally left the switch in "Valet" mode for Brians run.

I reset the Valet to 1800, and just in case I was feeling confidant I set the Normal to 1900 series amps. I'd decide after the burnout which to run. If I turn it up too high the tires would spin and that really slows down the acceleration, but the track was well prepped and very sticky. This last run of the day is the one of which Seth posted the video. As you can see the burnout was very nice and so I chose the 1900 Amp setting for the run. I must have been a bit jumpy because I red-lighted on the launch with a .484 reaction time.  The tires stuck, the extra current dropped the 60 foot time from the last runs' 2.059 to 1.904. At the end of the track I came through the lights with a 13.810 at 98.38 Mph. A mere .056 seconds slower than the record that Plasma Boy took away from me... Shucks, I should have put Brian Hall in it, we may have pulled it off with his lighter weight. ;-) Still I was amazed at the performance.

In reviewing the Orbital batteries, it's important to note that they are also lighter than the Optimas were. 40 lbs vs 44 lbs. And also that I have only been testing the peak power capabilities, not the range or life. But obviously they make the car faster, and according to the Speed World HP estimator it's not just because they are lighter. When I put in the weights and speeds for the best runs with the Optimas and Orbitals it shows that the Orbitals give a bit more than 10% more power. And they are doing this at only 90% of the weight.
The batteries were sponsored by Exide. I am very thankful to them for that, but I have no obligation to them for this. If they didn't work well, you would hear that as well.

After the last run I remembered that I promised Madman Rich Rudman a ride (or maybe he reminded me). So off we went around the parking lot at high power. I think he enjoyed it, but his extra weight must have taken a toll on the contactors. When I tried to put the car in reverse it threw an error code. Back at home I found that the forward contactor for one of the motors had welded shut. I popped it open and everything worked well again. I guess there are some drawbacks to having higher power batteries.

Overall, I had a great time at the Vegas races this year, and I expect that many people feel the same.

Have fun!

Movies of my last run are at:

Thanks to Exide, my battery sponsor:
Here's what I'm running.

And to Rich for making such a nice charger:

Horsepower Calculator:

http://www.CafeElectric.com/  Home of the Zilla.

http://www.evcl.com/914  My electric 914

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