Wednesday, April 6, 2011

1,000 Charges and Still Going Strong!

Recently I passed the 1,000th recharge milestone with my MINI-E. That's considerable when you realize I have only had the car about 660 days so far. I've put 54,000 miles on it so that's over 80 miles per day, every single day I've had it. Obviously I haven't driven it every single day, so the days I have driven it I've probably averaged above 90 miles per day. That's a lot of charging, more than 1.5 times per day actually. Actually, the car is such a pleasure to drive, I find myself using it for everything I can, whether it be personal or for business use.

Those of you that follow this blog know that I occasionally write posts about my experiences for sites like Edmunds, AllCarsElectric and most often, I was talking to Brad Berman, editor of plugincars recently and he asked me if I would write a post on my range throughout the year in different temperatures. I was actually working on just that to post here, and planned to post it once I hit my 1,000th recharge. So instead of a full post here about it, I put it up on the plugincars website, that way it will reach an even greater audience than here, and give more people a chance to see how the car has performed. You can jump to the full post HERE.

A lot of people ask me about the range in extreme heat and cold, and whether or not I am beginning to notice battery degradation now that I have over 50,000 miles on it. I really haven't noticed any degradation, but my data seems to show that it is beginning to happen, as the second year data shows slightly less range that the first year throughout almost all temperature ranges.What the real usable life of a EV's battery pack is still debatable. There just aren't enough of them out there that are using the newer lithium ion chemistries that have been driven enough miles and charged enough times to have reliable data on, so I'm sure a lot of people are interested in the data that I've accumulated over the past 22 months.

Remember, the MINI-E is a prototype test car, and does not have a sophisticated thermal management system. The passive thermal management system it employs is really primitive, making this car particularly vulnerable to weather extremes. BMW will be using an active thermal management system on both the ActiveE and the i3, based on lessons learned from the MINI-E trial lease program: Here's what I've observed:


  1. Really interesting numbers, I'm still amazed at the level of detail in the records you've collected. I tried to keep track of everything, that lasted for about 3 months before I gave up.

  2. Hey Robert, How's the volt?
    I have become so used to it now that it's second nature. It just takes me about 10 seconds to toggle through the gauges and write down the info in a clipboard I keep in the car. Every few days I enter into an Excel spreadsheet and it calculates the averages for me.
    It did take me a LONG time though to sort through all 1,000 entries and group them into first/second year by groups of every 5 degree change in temperature. That was a workout!

  3. Very impressive Tom. That's a lot of charging. I am encouraged to see that the range has only slightly reduced. The next 1,000 charges will be even more telling. Please continue to keep us informed, you are offering information that simply isn't available anywhere else because so few people have the electric car experience that you now have.

  4. It would be nice if you listed the minimum and maximum ranges you have observed as well as the averages

  5. Great job Tom. That had to take a long time to compile. BMW should be paying you for this