THis week we talk a bit about several small things. Heat seems to be a pretty simple topic. It is hardly in the ballpark with range issues – right?
Actually, at least for us, the range issue is almost entirely manufactured by the media. Heat in an electric car, on the other hand is very real. It becomes more real as the temperature indication drops. And indeed at about 20F all thoughts of range kind of go by the wayside.
In fact, one evening in the Mini Cooper Clubman, my wife and I went to dinner. I left the car “running” for an hour and a half while we dined with the heat on. This so the car would be warm when we left. Unfortunately, when the ignition was on, the running lights were lit as well. We had four different parties stop by our table to advise us we had left our lights on, concerned that we would run out of battery and be unable to start our car.
We had a 34 kWh battery, and we were dining about two miles from the house. The temperature was 22F. Range wasn’t the topic of the evening. Nor did I car if the battery “ran down” at about 8 amps and 360v. What I cared about was the car was warm when we came out. We could charge at home.
This week the Cadillac Escalade EXT. This has not been a problem free build. In fact, it is probably the hardest and most complicated we have tackled and we have yet to declare victory. But I have to tell you I am driving it daily and it is just a joy for me personally, even clouded by the vast amount of ducats it has eaten along the way. Most of the time it is very smooth, quite powerful, very quiet, and the six speed automatic transmission works beyond my fondest hopes. I recall a LOT of our viewers simply “advising” in their vast experience with electric Cadillacs that we would never get this transmission to work. Thanks for the vote of confidence guys.
We DO have ongoing issues. Something periodically upsets the ECU and it goes into a coughing fit at 3000 rpm any time we hit that magic mark. At other times it does not display this AT ALL. ANd it is really quite random. We have fixed it a dozen times. We change something, it goes away for two days, and then comes back. That’s because it is very intermittent anyway. Frustrating. Annoying. But not terribly important even when it is occurring.
Heat is something else. We had devised kind of a complicated system using a very high power whole house tankless water heater system. Great lesson in there. It was designed apparently to be in a house. Reminder once again that the automotive environment can be harsh. It lasted days. And with two heater elements, one blew up, and then the other.
In this episode, we go to a bit of a more robust heater system – a liquid heater from Kim HotStart that is designed for diesel trucks, caterpillar tractors, and diesel locomotives. They have been making this device since 1942. It’s basically a cast aluminum tube with a water heater element in it.
Our control system remains problematical. After the show was edited, we had a total failure of the temperature probe. It’s easy to replace, but it was supposed to be immersible and accurate. They didn’t mention the part about it lasting a few weeks. I’m hoping it was a fluke.
The system is both expensive and a bit complicated. Glycol/water heating has great attraction because you can leave your cabin environmentals entirely alone. You’re basically just spoofing the engine heat normally supplied. But you have to circulate it. You have to control the temperature of it. And it takes a lot of power. We are currently doing about 3700 watts in the Cadillac and it may not be enough. I’ve ordered a 4000 watt 240v element to replace one of the 2500 watt elements.
You also have to be very careful that it doesn’t run away with you. The penalties are severe. Unnoticed, if it somehow is left on it poses a dire threat to your battery pack as this is a significant load and if not detected, it will drain your pack to 0.000v overnight. Even a 76 kWh pack.
Second of course is the fire hazard. PLastic and high temperatures don’t mix. Fortunately, we have a solid cast aluminum tube that on full meltdown can’t really meltdown.
A number of viewers, ever helpful, have pointed us to the MES-DEA RM4 system. Actually we installed one of those in the Mini Cooper 3 years ago. It went entirely dark within a month. We had bought it from Victor at Metric Mind. WHile he ordinarily provides probably the poorest support and the greatest amount of excuses of any component supplier, in this case he replaced it immediately. In fact we had one before we could remove the old one and return it. While he nornally disclaims any knowledge of his products and definitely any responsibility for them, noting he’s just a middle man, in this case it went very easy. Turns out he WAS familiar with the problem and we werent’ the first replaced.
The replacement seems to work well and we’ve had no further difficulties. But one vehicle fire has been blamed on this device. An MEA-DES has discontinued it, promising a corrected version in the future. They were then absorbed into another company and nothing further. Victor is discounting his stock of some 60 remaining units at a very attractive price. We’re going to pass.
Our little Lang solar hot water system pump continues to annoy with it’s very high price, and amaze with its hardy willingness to move the liquids entirely silently. As you know by now, I have a weakness for good components and this one rates as EV jewelry.
Another area where we’ve just had famous experience with is Summit Racing’s black aluminum AN fittings. When used with the black nylon rubber hose this removes all my problems with leaky hoses and the cheap band hose clamps that plagued the vehicles of the sixties and seventies. This system is just leakproof. We have all of that in our cooling system kit. If I can work something out with HotStart, maybe we’ll do a HEATING system kit.
In this episode we also do a survey of the Azure Dynamics DMOC845. As you know, we purchased a large lot of Siemens 1PV5135 motors and AZD DMOC645s. We’re working on a generalized vehicle control unit to control it over CAN bus. Well, Collin Kidder is doing most of the work of course. And I’m doing what I do best, approving of all that work and cheering him on.
But AZD also received a $5.4million Department of ENergy grant to develop an “advanced traction drive” for the future. This is simply careful wording of a grant application. What they were doing was simply developing their next version of DMOC. You can really afford the very best components when you’re doing it with other people’s money and they spared no expense. Actually I’m since advised that Rinehart Motion Systems also uses the SKiM power module from Semikron. You can find these online from $1800 to $2300 onesey/twosey. I’m told that AZD had a stash of $1.8 million worth of these but I haven’t seen them surface.
In any event, modules like the 93mm SKiM and the Sprague SBE film capacitor, dramatically simplify the development of a three phase controller. It still needs some software and a multicontroller, but the controller used in the AZD DMOC845 is about on par with an Arduino Due. I think I see on the horizon the end of the $10,000 controller market. There should be something in the $4000-$5000 range for 150kW soon. With a GEVCU at certainly less than $500 somewhere, and a DMOC645 at $2500, I think we’ll look pretty much a bargain at $3000 for some time. At least until Curtis works out the concept that there is a market for a 150 kw controller. Man are those guys slow on the uptake. But the little AC-50 with Curtis controller is a relative bargain with the motor and controller both for less than $5000. The 75 kW restriction just eliminates too many cars, but we love that system for our Speedsters and so forth.
That’s about to get better as well. We’ve already sold our AC-75 prototype. We’re supposed to receive two production units this week. The AC-75 is a much larger motor physically – about the size and weight of the Siemens and really with a very similar power rating. While the controller is limited to the same 75 kW, the motor is rated for 180 ft lbs at 108volts. We run these at 120v and the torque has to come out very close to the 220 ft lbs the Siemens delivers at 300v and 400amps.
On the topic of temperature, the Argonne National Labs has set up an Advanced Powertrain Research Facility. And they are doing some great testing there. They recently put a Leaf on a dynamometer. This is a very good technique for checking range etc because you can program the system to drive the car to a defined route that just never varies. Actually it varies all the time but you can do da drive and then duplicate that exact drive. This is impossible in the real world as lights and traffic are very dynamic.
In this case, they put the Leaf on the dyno for several different drive profiles. The variable was the temperature. They ran it at 20F, 72F and 95F with a simulated 850 watts/square meter “sun” on the 95F run. The concept was to determine the effect on range at different temperatures.
I love this test. And I don’t. First, I’m very curious what would happen to the batteries themselves. BUt it is also interesting to see the effects of running the heater and air conditioner. This of course depends on how powerful a heater or air conditioner was installed on the car. But assuming it was adequate to maintain the 74 degree cabin temperature, it is very interesting.
Why all this temperature talk? Well, it’s February here in southeast Missouri. I intensely dislike the environment here during two months, February and July. In July, it is too hot and humid to bear. And in February, it is too wet and chilly. I would go for a ten month year here, but I fear the young socialist democrats on CNBC are the only ones hopelessly naive enough that I could get to take up such a notion.
I have to tell you I was a bit reluctant to do an Electric Vehicle Conversion Convention this year. We had a great convention last year but a number of key individuals from the previous year didn’t make it. It was a weird year with an election and a messed up economy and so forth so a number of guys I assumed would be with us just weren’t able to come. True, we nearly doubled in body count and vehicles and the ShowMe Center was a great venue for what we were doing. But these events are very stressful on a small organization. Brian left in August. And you have to work at it pretty much full time for six months, then all of it hinges on a few days of the event itself. Anything can wipe out your careful plans. Airline strike, terrorist attack – even if its somewhere else, weather, anything. And you’re still on the hook for all the expenses and of course all the work you did leading up to it. The vendor support is tepid. Indeed I wondered if I wasn’t just being taken advantage of.
Nick Smith was the first to sign up for the first EVCCON. No one suffers more difficult nor expensive logistics than Nick. But he’s got the EV fever pretty badly and is struggling to get a components business off the ground in Auckland New Zealand. He was ALSO first to register for EVCCON 2012 and showed up early bringing friends. He wants one for 2013.
So I decided to throw the vendors under the bus – they can come or not as they like and find convenient. We’re going to host an Electric Vehicle COnversion Convention for Nick Smith and in fact, I’ve invited him to be our keynote speaker. John Hardy of Surrey in the UK immediately signed up to speak as well. And so we are hoping to do it again.
I’ve selected a bit smaller interior space, the AC Brase Arena, with a large surrounding park. And an often hot time of year – August 6-11. I always say if we can make it to August 15 the heat is mostly over. Unfortunately August 6 is on the wrong side of August 15, so it might be a bit warmish.
Other differences. We are expanding playday from half a day to all day Friday. We already have the dynomometer guy eager to come back and do it again. He was just fascinated with the electric cars last year. We’re going to shorten the drag strip from the quarter mile to an eighth mile run to provide more rundown space. This should let the fast cars “let the dog out” without danger of winding up taking off on one of our runways.
I have already heard from several of the missing warriors from the first year who intend to return now. I don’t know what size it will be. But we are looking hard for ways to make it more enjoyable and meaningful for those who do attend.
One thing we’re going to do is recognize the guys who DO go through the heroics to bring their cars. In a sense, they are cohosting this event. And so indeed we are going to recognize this. No, they don’t have to pay a portion of the shortfall we seem to run every year financially, though that would be a tempting notion. But we’ll have some different shirts and caps etc for this group so the rest can easily identify them. Maybe even numbers for their cars and shirts so you can easily match them up for advice and questions. When you stop and think about it, they are and always were the stars of this event.
I’m always torn about this event. Having done trade shows in the past, I am naturally keyed to seeing it grow to success with 5000 attendees and a 100 vendors. Probably have to move to the Bay area to get that to happen. But the fun for me is 35 guys in the shop, all of us studiously trying to figure out what’s wrong with Jason Horak’s car up on the lift.
It remains a mystery…