Sooooo much fun until….

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CooperDeux

CooperDeux

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So I took my new Mini out on my favorite twisty road. It was *ridiculous* amounts of fun. I was a bit apprehensive because the steering feels less responsive than my ICE Cooper S, but the weight distribution is lovely and the steering is forgiving. I was flogging it as best I could, braking hard before every corner and accelerating hard out of every corner. It was savage fun until it wasn’t. After about 15 minutes of hard driving, the electric go-meter (the yellow one on the left) dropped to about 50% available power. If I took it a little easy, the go-meter would climb back up, but as soon as I jumped on the gas (er…electricity) the available power went back down. I had read a review in Motor Trend (or something similar) and that issue was brought up, so I wasn’t terribly surprised, but it was rather disappointing. My question is this: is this due to overheating of the batteries? The motor? Or does it have to do with capacitive potential and other electrical things of which I know nothing about? I’m developing a love-hate relationship with this car and am very close to naming it Stuart. Soooooo much fun until it petered out.
 
Probably the stator in the motor…
The Ora Good Cat has the same problem when being driven hard up steep hills in Thailand according to Bjorn Nyland.
 
CooperDeux said:
So I took my new Mini out on my favorite twisty road. It was *ridiculous* amounts of fun. I was a bit apprehensive because the steering feels less responsive than my ICE Cooper S, but the weight distribution is lovely and the steering is forgiving. I was flogging it as best I could, breaking hard before every corner and accelerating hard out of every corner. It was savage fun until it wasn’t. After about 15 minutes of hard driving, the electric go-meter (the yellow one on the left) dropped to about 50% available power. If I took it a little easy, the go-meter would climb back up, but as soon as I jumped on the gas (er…electricity) the available power went back down. I had read a review in Motor Trend (or something similar) and that issue was brought up, so I wasn’t terribly surprised, but it was rather disappointing. My question is this: is this due to overheating of the batteries? The motor? Or does it have to do with capacitive potential and other electrical things of which I know nothing about? I’m developing a love-hate relationship with this car and am very close to naming it Stuart. Soooooo much fun until it petered out.
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This problem has never happened to me, which probably means I'm a wimpy driver. The overheating/power-limiting you reported also happened to Kyle when he took an SE to the track in this YouTube video. I would like to know what MINI did to prevent this power-limiting when they configured a MINI Cooper SE for use as the Formula E safety car.

@Giosan just posted his positive experience racing his 2022 SE. I asked if he had experienced this overheating/power-limiting problem.
 
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You could get the OBDII information to see the temps. Likely the motor since it doesn't have active liquid cooling like the batteries.
 
I can't find the exact information, but this gives an idea. The motor is rated for maximum power and 30 minute power. It will overheat if you use full power for too long, and hence throttle the power. Here is a PDF of the i3 (not i3s) and i8 https://ia801005.us.archive.org/11/items/BMWTechnicalTrainingDocuments/ST1403a I1 Complete Vehicle/20140404_BMW.pdf . If it were cumulative, then 30 minutes at 75kW would be the same energy as 18 minutes and 125 - although losses are higher with higher current. If the i3s (and MINI) motor had the same 30 minute total, then it would be 16 minutes at full pop before having to throttle. Of course it may not be linear, and this was just an example, but you can't run the BMW hybrid synchronous motor at full tilt for very long. With extra cooling of the motor you could. Track car, the MINI isn't. City warrior, now you are talking.

As an aside, even the mighty Tesla S overheats around the Nurburgring. Our MINIs are hyperactive little balls of fun, but like having a rest between bouts.
 
I worried about heat-soak for about 10 minutes when considering buying this car. It gets pretty toasty in my area in the summer, but I don't plan on tracking this car. I plan on enjoying it. Vader has it exactly right -- this isn't a track car, so don't expect that. This little beast is a super fun town car. I'm going to test range this spring going up into the Sierras, but I honestly don't care about the outcome. I actually just sat in my car last night while it was charging, talking to my Dad, who is a hyper-critical hyper-miler, and gushed about this stupid little car. He understood, as I do, what the expectations are. Just enjoy it!!
 
I had this happen recently when I was driving at constant speed on the freeway, pulled off and stopped for about 5 minutes, then floored it back onto the freeway. It was about 40 degrees Fahrenheit so I was pretty surprised it overheated with just one deceleration and acceleration. But all the yellow bars returned after a minute or two.
 
That's troubling, for sure. 40F and it couldn't deal with it?? In the last week it's been flashing <37F but on the freeway I'm going >90 MPH and no issues. What's your Location? Have you talked to your local dealer?
 
So, maybe a dry ice pack, or several, stuffed under the hood might be a simple solution for turning the SE into a more capable track car? Time attack? Hummm…


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fizzit said:
I had this happen recently when I was driving at constant speed on the freeway, pulled off and stopped for about 5 minutes, then floored it back onto the freeway. It was about 40 degrees Fahrenheit so I was pretty surprised it overheated with just one deceleration and acceleration. But all the yellow bars returned after a minute or two.
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I nail it onto the freeway every time and have done so before and after cruising at 90mph at temperatures warmer than 40degF so something doesn’t sound right.
I suspect the battery may have been too cold and/or the charge level low?
No way the motor should overheat in those conditions.
 
CooperDeux what was the state of charge of the battery? I have driven spiritedly on Angeles Crest Hwy with above 50% for about 30 minutes on three occasions and never received a loss in power.
 
It’s a 2022. The battery was fully charged or close to it when I left. It was about 0 Celsius (for the Brit’s). I think Vader hit it on the head. These are little balls of energy (literally) that need a rest between sessions.
 
fizzit said:
It was about 40 degrees Fahrenheit so I was pretty surprised it overheated with just one deceleration and acceleration.
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The e-power can drop for other reasons as well, I have gone as low as 30% in extremely cold weather. There may have been an electrical discharge issue at play, not the motor overheating.
 
fizzit said:
I had this happen recently when I was driving at constant speed on the freeway, pulled off and stopped for about 5 minutes, then floored it back onto the freeway. It was about 40 degrees Fahrenheit so I was pretty surprised it overheated with just one deceleration and acceleration. But all the yellow bars returned after a minute or two.
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I have also had this happen. I attribute it to cold rather than heat because doing the same thing at 50F didn’t cause the power limit.

Electronics are more efficient at low temps, and heavy power draw can cause more current. It could be that the car is protecting itself from too MUCH power. Just guessing there. But try the same thing when it is warmer (but not hot - say 50s or 60s). If it still limits, there could be something wrong.


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CooperDeux said:
Luis: spirited driving won’t do it. It has to be savage.
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Ahhh!

I actually tried to get it to reduce power on a couple occasions, 100 degree days too. Must be too many twisty roads near me that prevent full throttle for more than a few seconds at a time.
 
I’m in Tucson. Duh!

Desert.
Hot.
OK, real hot!

I’ve never experienced ‘reduced propulsion’, and I drive it like I stole it most of the time.


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At 5F, my power is consistently at 60%. It's plenty adequate for city and freeway driving but probably not the greatest at the limit.
 
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