Wiring Connections - In Teslas and In Nations

Tesla introduced their long awaited fabulous gull wing SUV - and apparently the entire planet yawned in amazement. The stock sagged. True, VW is scampering into the EV space with strong eGolf sales, announcement of a VW Phaeton and a Porsche supercar in electric. But it is a bit like the puppy wearing the "cone of shame" around its neck after being a bad dog. Are electric cars where car makers go when they are being punished?

So what's happening? I believe it is a combination of battery suspicion, range, and the expected value proposition. Tesla survives with a strong battery warranty, a range that is regarded as "about sufficient" and the value proposition is weak but appealing to enough early adopters to make the sale. And the interest IN Tesla among those who just cant afford it promises to offer some price support in the secondary market - preventing the price collapse worn so proudly by Nissan and Chevrolet in depreciation.

Rather than evade change, we kind of have a policy of embracing it. We may actually be a little out in front of it in some ways. We still get a lot of orders for CALB batteries for some reason. I have ceased stocking them but we can get them in a day or two from CALB in Pomona so no problem. But guys, its over. I have an entire Chevrolet Volt battery pack sitting on our floor that was less than $2000 delivered and is fully functional.

No it's NOT as good a battery and indeed it may be dangerous. And it is certainly inconvenient. Quite a bit of work to disassemble it and get it in a car. But it doesn't matter. It's $2000 delivered. The same capacity in the CALB series would near $7000. We finally have lithium batteries at a lead acid price. That's what you wanted. It is here. I see no point to pursue battery sales at all. If you want em, we'll get em. But I havent' even walked up INTO the battery lab in months.

The OEM discards and salvage will be good enough. And I really expect them to "get over it" here in another year and just sell them through their dealers to anyone and everyone that thinks they can use them. A brand new set at Nissan is listed at $5500. You can't order them now. But in the future they are going to get the Kentucky Fried Chicken religion and realize that "parts is parts". Nothing more. Nothing less. We view it with the same consternation as if they had decided to restrict carburetor sales because they thought it was a secret or something that they used them. They are just a tad overawed with their own technology for a company with a battery factory operating at 10% capacity.

So if they have them stacked up and going begging 500 miles from my lift, why am I importing them from China? Ultimately, the irrational does become rational unless gravity completely fails us. But it does on occasion take a bit of time.

I have been chanting for a year - OEM components. After losing some in the fire, I ordered three brand new Chevy Volt chargers for stock. We can sell them and make money at $1800 each - less than the price of the Brusa orphans we carry and same power. But much better. Liquid cooled. Very simple setup. And if it blows chunks, you just turn it in at any Mr. Goodwrench location for a new one.

In a few months, we'll be offering 10kW Tesla chargers at less than $3000. We have Volt DC-DC converters at $1000. And so the price falls and the quality goes up. Better, we gain access to worldwide parts distribution and availability by availing ourselves of the automakers supply chain.

But beyond this, I think we'll gain a lingua franca of EV design. Instead of every home built EV being impossible to sell and impossible for anyone else to maintain, I think within just a year or two you'll see knowledgeable young Haubers looking at something someone dragged in and instead of shrugging his shoulders helplessly, he'll be noting "Oh yeah, Leaf drive train, Chevy charge system, Tesla DCDC converter - I know what this guy did. We can work this out. LOOK it's got one of those early clunky EVTV controllers. This is a collectible."

In other words, tribal knowledge of the components and wiring necessary to use them. Not exotic tribal knowledge. Just commonly known things.

Knowing where we are going is important. Getting there can be problematic. Our work on the Tesla Drive Unit continues unabated and unrequited. We'll get there, but it is a bit of a grind. I'm rewiring our test rig to where it can be stretched out across the shop and used to run full subclips on the test stand. It dawned on me I might as well have 20 of them made up in China. The wiring instructions will be extensive for those that have to make the connections themselves. We should probably offer a wiring harness with the system. And as I sketched it out, it kept growing.

We kind of have an informal waiting list already of builders who want to use the Tesla Drive Unit. One wants to develop a serious race car using the drive train. It points up how integrated and specialized the Tesla Drive Unit really is. It works great in a street car. But there have been reports going back to the Roadster of attempts to use Tesla's on the track that simply don't work out well - on temperature issues. I fear it will remain so.

Inverter/controllers/powerswitch IGBTs usually start getting pretty sick at 85C. So they often have current limiting strategies that start coming into play at 80C to keep them below that temperature.

AC Motors are somewhat hardier. They can operate at 150C or even higher - 175-180C in good shape. In my mind, this is pretty simple - simply route the cooler coolant from the heat exchanger through the inverter first and then into the motor. In practice, the nature of thermal dynamics simply doesn't work like voltage and current. If I put a temp gage at several locations in the loop, they ALL seem to measure the same temperature. I assume this is simply because the coolant is very very good at moving the heat around in a small system.

In any event, the heat exchanger has a large effect on the temperature of the system. But where anything IS in the loop doesn't seem to matter. So we wind up with the motor heating the inverter until it shuts down.

The Tesla design is very integrated. But it has the same basic flaw. The motor and inverter are on the same loop. We've had better success having entirely separate coolant loops for the inverter and the motor.

The past few weeks have been somewhat blurred by activity. In addition to the fire, I sold off N341A, one of my beloved DC-3 aircraft. I remain fascinated by the technology of the 1930's. The DC-3. The Zephyr train. The Hindenberg Dirigible. It was a time of enormous technological advance, but also of technological optimism. With the world in an economic depression, technology seemed to offer the promise of a utopian future that reached a crescendo at the 1939 World's Fair. This shaped a generation of Buck Rogers fans as well as Commander Cody and the Radar Men from the Moon. The 10-year olds of 1939 wound up manning the panels in Houston for the 1969 landing on the moon. And of course that led to all things microprocessor based - basically our world today.