Tuesday, May 24, 2011

After More Than 57,000 Miles, a 100 Mile Trip is Still No Problem

The other day I needed to go to a meeting at an office that I had never been to before. As always, I checked Google maps to see how far it was for two reasons: how much time will I need to drive there, and can the MINI-E make it or do I need to take my Toyota Tacoma that day. It's not often when I need to take the truck because I'll need to drive further than the MINI-E range will allow, but it does happen once every couple months or so.

When I checked Google maps it was exactly 50 miles away, and about one third of it was highway driving. My initial reaction was that I wouldn't take the chance, it's cutting the range too close and why risk having a problem. A big part of my reasoning because it has been unseasonably cool and rainy here in NJ and the difference of driving in 50 degree temperatures in the rain from 70 degree temperatures might be 10 miles of range or so.

Anyway, I then checked the weather channel and learned that the day I was to go to the meeting we were supposed to have a perfect day, clear and in the mid 70's. So then I started thinking about it, and it didn't take me long to come to the decision to take the MINI-E and take my chances. The plan was to drive there as slow as I could do safely, meaning 55mph on the highway, and the speed limit on the secondary roads using regen as much as possible, even trying not to use the mechanical brakes at all.

As my journey progressed it didn't take me too long to realize I wasn't going to have any problem. In fact, I arrived there, 50 miles later with 60% SOC. I had only used 40% to drive 50 miles! I did drive as efficiently as possible, and drove slower than I normally would, but this guaranteed me that I would make the 100 mile journey and I could even drive any way I wanted to on the return trip without worrying about being extraordinarily efficient.

So I the trip home I drove 70mph on the highway and didn't concentrate on using the regenerative brakes as much as I possibly could. I arrived back at the restaurant with 15% charge remaining which would be good for at least another 25 miles and if I really wanted to push it probably even 30.  I then plugged in and in under three house I was fully charged and ready for more another 100 miles if necessary.

When you add the 62 miles I drove to and from work that day, I drove the MINI-E 162 miles, not bad for a electric car with roughly a 100 mile single charge range. Anyway, the good news is that after more than 57,000 miles and over 1,100 charging cycles, the car still has the same range it had when it was brand new. This is significant because there are a lot of concerns about battery degradation in electric cars. It's going to start to happen at some point, I know that, but it is a bit surprising to me that I have been able to drive and charge the car as much as I have without noticing any decrease in range or battery capacity. This is good news for all electric cars in my opinion. 


  1. Battery life over time will be heavily dependent on the quality of charging; looks like MINI/BMW did a great job in that department!

  2. What is the expected life of these batteries anyway?

    Antonio Legasse

  3. Antonio: That is one of the things everybody is trying to figure out. Most experts expect the batteries to be good for 100,000 to 150,000 miles depending on how they were cared for. That would account for approximately 3,000 to 4,000 charging cycles.

    It's not that the batteries will be dead then, just that they have degraded to 80% of their original power so when a 100 mile EV can only go 80 miles on a full charge, it's considered to be done. You could of course continue using it for years to come if you don't need the extra range.

  4. Good news! Keep up the great reporting Tom

  5. Great news on battery life. Now they just need to get battery pricing down by half and ranges up by 50% or more to make these cars more attractive to average consumers.

  6. Anonymous: I'm sure you understand we are in the first generation (the mini-e isn't even 1st gen, it's a test car)and as with all technology, the 1st gen is always more costly and needs improvement. Now that there is significant investment in battery technology and many of the major OEM's are forming partnerships to develop newer, better & cheaper batteries this will happen.
    For the time being though, a car with a 100 mile range like the MINI-E will outsell it's supply for a while as there are many, many people that could use one as a 2nd family car.
    The ranges will get better and the batteries will get cheaper, just like all technology does.