Battery Powered Cars – They’re Not Just for Kids Anymore

Bob Bressler is a customer of Tesla Motors and owner of Bressler Vineyards, a small producer of super-premium Napa Valley Cabernet Sauvignon. An expert in the Internet and networking technologies, Bob’s career prior to becoming a full-time vintner spanned executive positions at Sun Microsystems, 3Com and BBN. We asked Bob to share his perspective on electric cars and the Tesla Roadster.

Why did I order a Tesla Roadster? Believe me, my wife has asked me that question many times. I guess there is no single reason – but a long list of them.

For many years, I had a turbo charged Callaway Corvette and I used to zoom up and down the Silverado Trail reveling in its power. Over time, though, I have been moving in more environmentally friendly directions. There is a fair amount of debate as to how we are changing the environment, but it is clear that we are and not in a managed way. Getting control over how we are using fossil fuels (both from an environmental as well as a political point of view) can only help.

When I am carrying around wine, I use my Hybrid SUV. (Yes, it is still an SUV – but wine weighs a lot.) For around town, I have a Sparrow. A completely electric car, the Sparrow carries you (and only you) around in relative comfort. It has a little bit of room for extra gear (and I mean a little). I can load in exactly three bags of groceries. (I learned that last point the day I bought four bags.)

Unfortunately, like all EVs up until now, the Sparrow has severe limits. It is powered by 13 deep-cycle, lead acid batteries. Lead acid batteries were invented something like 150 years ago. They are nice in that you can draw quite a lot of current from them, so my Sparrow is pretty quick off the line and can zip around at highway speeds. Unfortunately, the other side of the coin is that the power storage density is pretty low, so with 13 batteries my most optimistic range is only 40 miles – much less if I accelerate hard or go fast. It is hardly fair that I have to give up sports car performance and a reasonable range just to have a technology that I want!

The obvious next step would be to replace the lead acids with Lithium ion (Li-ion) batteries. With half the battery weight, I could get 150 mile range. That sounds great, but in reality you can’t really buy the inexpensive, high-volume Li-ions used in laptops and camcorders. The companies that make the high-volume cells (the 18650 models) don’t want to sell them to individuals because of the liability issues. Plus I’d have to invent my own battery management system. (It is embarrassing to have your car catch fire at a stop light. Although, come to think of it, my Callaway did that once. Too much boost.)

The good news is that the Li-ion batteries that you can buy for electric vehicles have at least some kind of battery management system built in. The bad news is that those batteries are extremely expensive due to the low volume. My 150-mile range would cost close to $60,000 just for the batteries. And I would still only be able to carry three bags of groceries (and not my wife). Bad deal.

By the way, battery management is one of the most important developments for an electric car. There are the obvious safety issues involved in keeping the batteries in a safe operating range including watching out for temperature problems, monitoring charging performance, and just getting the most out of your batteries.

But for most drivers, one of the important battery management issues is the “fuel gauge” – how much further can I drive the car? You can measure how much charge you are putting into a battery and how much you are taking out – but not how much is still in the battery. Well, you can, but only with reasonably sophisticated algorithms. Nothing like a simple e-meter. And that is a key point with the Tesla Roadster. It has the sensors and the CPU power to figure it all out.

Without the right technology, what’s a fella to do? Thankfully, I found the Tesla Roadster. It answered all my concerns.

  • It is plug-in technology. The United States gets almost all of its electricity from coal, nuclear, natural gas, and hydro. This is important for three reasons. First, there is a much greater supply of the resources needed for that energy. Second, the use of oil has at least as large a political impact as an environmental one. Third, it is much easier to incorporate new technologies that can add power to the electrical grid than to develop small mobile technologies that will fit into a car.

  • I can have the sports car performance I loved in my Corvette and can still pretend that I am Graham Hill.

  • I can drive all the way from my home in Napa Valley, Calif., to San Francisco without thinking about fuel. (My Sparrow is legal for driving in the carpool lanes here, but there are no carpool lanes within the range of the car. With the Tesla Roadster, I’ll get the carpool lane AND range.)

  • I like having a car that has other people smiling and thanking me. We get more than our fair share of Ferrari and Lamborghini exotics in Napa Valley and I love parking my Sparrow next to them. When I come out of the store, are people crowded around the Ferraris? No, they are all looking at my Sparrow. More and more, people understand the importance of environmental issues.

  • I can carry a passenger! Okay, I still can’t carry many cases of wine, but one thing at a time.

  • I have battery management. With a sophisticated computer driven system, the car can give me the pertinent information I need. Good news, it is all just software. It is easy for Tesla Motors to adapt as people start using the cars and find out what they really want to know. And, as I mentioned, they have the software to do the “fuel gauge” the right way. They can measure what is going on in great detail and implement the right algorithms to give me a simple and accurate "fuel gauge."

  • They are using Li-ion the right way – i.e., they picked the technology being manufactured in huge quantity and have invested in the software to make a battery management system that adjusts the usage of the batteries for the best life, safety, and (of course) performance.

The day Martin told me that I could place my order, I did. I can’t wait!