Monday, November 1, 2010

MINI-E software "Upgrade": I'm Not Sure That's What I'd Call It

During the sixteen months that I've had the MINI-E now, there has been a few software "upgrades" that have been performed when I have taken the car in for the scheduled service every 5,000 miles. The reason for these are to correct any known "bugs" the software might have, like early on when some of the cars would jump from drive into neutral when you were stopped at a traffic light, and also to tweek the cars power output and regenerative braking to refine the driving experience and make it as smooth and pleasurable as possible.

When I brought the car in for service last week, Rob Healey, technical coordinator for the MINI-E, told me that they were doing a software upgrade and to let him know how I felt about the changes they made. Well it's only been about a week now so I'm going to give it a little more time before I email him to let him know how I feel about it, but so far I'm not really lovin' it. They did seem to make the transition from acceleration to regenerative braking and vise-versa more subtle and smoother, but the regenerative braking has definitely been dialed back a bit and I need to adjust to it. I have found myself using the actual brakes much more than I have needed before and I don't really like that. Perhaps once I get used to it I will adjust my driving to once again use the regen for most all of my slowing down and stopping, but for now I find myself having to use the brakes to prevent myself from running into the rear of the car in front of me or overshooting a stop sign or intersection. It may just be me needing to get used to the new program. After driving the car for so long I got used to exactly when I needed to let off the accelerator to slow down for a turn or stop at a light and I need to re-learn that again.

You might ask why BMW does this and that is a legitimate question. I'm not 100% sure but I assume they want to test different levels of regenerative braking for efficiency as well as customer comfort. I recently spoke to a Tesla owner who also drives a MINI-E here in New Jersey and he said the MINI-E's regenerative braking is much stronger than Tesla's. He needs to adjust every time he drives one car and then the other. Some people like very aggressive regen and others don't want it to feel like they released a parachute to slow the car down every time they let off the accelerator. After driving the MINI-E I have learned to love the aggressive regenerative braking and for me, the stronger the better. Personally I think all EV makers just allow the driver to adjust the regen to the level they feel most comfortable with. I'm sure it wouldn't be difficult to have that as an option that the driver can set to the position they like.


  1. But slight applying of the brake pedals will break regenerative instead of the disc brakes? So you don't loose range, you just have to change your habit?

    Though a manual option seems very interesting!

  2. Hi Tom,

    Just FYI, had my car serviced last week and I have not noticed any changes.

    I'll focus on the regen after reading your post but it feels the same to me.


  3. Anonymous:
    No, applying the brakes doesn't disengage the regenerative braking, it assists it. The thing is, I got so used to the strong regenerative braking, that I almost never used my actual brakes, now I need to use the real brakes to assist the regen when slowing down.

    I don't think you got the "upgrade". When I was talking to Rob Healey I got the feeling that I was the first to get the download and he asked for my feedback on how I liked the changes. The regen is definitely less aggressive, maybe I just need to adjust to it, but for now I feel like I need to really pay even more attention than usual.

  4. This is very interesting. I did not think the regenerative braking would be so strong that you could drive without using the mechanical brakes. On my Prius, the regenerative brakes are activated by the brake pedal itself, not the gas pedal. I would like to drive one of these to see if I like it better than the way the Prius activates it.
    Is this how the next BMW electric will work? How about the Nissan leaf and Chevrolet Volt, do you know how to they apply regenerative braking?

  5. I can see how this would be more versatile if it were adjustable as you suggest. Kind of like how some cars have a sport or economy mode.

    This is a very informative blog - good job Tom.

  6. Jerry,
    the Volt can be set to use releasing the accelerator to break, when in Low, but in Drive it drives like a normal car, with the regen breaking on the break petal. Last time I drove it the regen wasnt nearly as agressive as the Volt, which is ashame.

    The amount of regen should be a driver setting, I suspect most people would like it small at first but would gradually increase it.

    has the regen stopped working do to the cold weather today?

  7. Hi Robert,

    No, I have never had a regen issue in the cold, did you when you had your E? I never heard of anyone having cold weather related regenerative braking issues, only in the hot weather.

    When the battery temperature exceeds 109 (I think)the regen reduces slightly and when you hit 116 degrees, it completely disengages. The reason being that regenerative braking recharges the battery and recharging a battery heats up up even more so the software tells the car to stop recharging the batteries in an effort to cool off the batteries. The same thing if yo plug the car in to charge and the battery is over 116 degrees, it won't charge.

    In the cold weather overheating isn't an issue so there shouldn't be any regen issues unless there really is a problem with the system.

    No news on that Volt think we were talking about. I'll let you know as soon as things get clearer.

  8. The Nissan LEAF has an adjustable regen of sorts.When eco mode is engaged the regen becomes more aggressive. When deactivated regen returns to normal.

  9. Tom,
    I had problems with regen not working on really cold days, as I would leave it outside over the weekend, when the battery temp drops into the 40's the regen would stop working, never got so cold it didnt charge, but for a month or so I only used it to commute, because I was afraid to take it on overnights on really cold days.

  10. Robert: Interesting. I only saw my batt temp in the 40's a few times last year. Since I park inside overnight and I drive a lot the battery keeps warm from use. Last year during the coldest days I would make sure to use the car for a while in the afternoon so it wasn't sitting in my parking lot all day without use. That helped to keep the battery temperatures in the upper 50 and 60 even on days that it was under 20 degrees outside.

  11. Tom,
    yea, if your using it, its easy to keep the battery temp up. but most weekends I'd drive 80 miles then plug it in on a 110 and have to leave it outside most of the weekend slow charging. If I could I'd try to drive it a bit Sunday to warm it up, but that usually wasnt possible. I like that the Volt has a pre-heater as some of the houses we are looking to buy dont have a garage.

  12. Yes, the ability to pre-condition the battery and cabin is a must on all electric cars. It seems that the manufacturers understand this also because all of the cars coming out have the ability to pre heat and cool while still plugged into the grid. The BMW ActiveE will be able to do this also. You can program all these cars to warm up or cool down a preset time every day so you leave in the morning with 100% charge and the battery and cabin at the appropriate temperature.

    Last winter I played around with this myself by using a portable space heater in the cabin and setting it on a timer to turn on about an hour before I left for work in the morning. On days I did this my range was much better than days that I didn't. I had it blowing in the direction of the vents that lead to the battery compartment so the pack was warmed up also.

  13. Tom

    I recall that they backed off on regen strength a couple times with software changes. Other bloggers commented on it also, but it was long ago.

    In Dec 2009, they loaned me Mini E #008 when my #458 was in for service. I recall it had very few miles on it, and drove mostly the same as mine except at very high speeds, where it had astoundingly strong regen. I mean at 90 mph.

    I think they are trying to mitigate what happens when you are in strong regen and hit sand or snow with one wheel. The regen cuts out for stability, which can be unsettling. They could make the ABS apply the foundation brakes on the rear to compensate, but that would be expensive software and validation work.

    Here was my post about getting a loner E:

    Jim McL

    PS Oh, and the one time I froze the battery so cold that it would not charge, the regen stopped too. But that is not what you are seeing I bet.

  14. Tom, I've never met anyone who owns a car with regen that wants it turning down so I asked Tesla "Why can't I crank up the Roadsters Regen to match the MINI?"

    "The traction control and abs programs are developed with the current level of regen factored into the equations, change that and it all changes."

    Hmm, ok, I'll go for that, it did occur to me that any more braking at the rear might make it a little tricky on a wet leafy bend on cold NJ night.

  15. Michael,

    Throughout the past seventeen months or so with the car BMW has "tinkered" with the programming and as a result the regen has been slightly altered a few times when I got the car back from scheduled service. I guess they are trying to find what it the most efficient use of it. I agree that everyone I speak to likes it to be very strong.
    I think the first time you drive a car with strong regen you may not like it because it feels unnatural, but after only a short time driving with it, you learn to love it.