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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!
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