Anyone keeping track of the battery's soh

vader said:
Not entirely true. You get 28.9kWh of a 33.6kWh pack. That is 86%. This gives a top buffer of around 11.5% and a bottom buffer of 2.5%.
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You had me questioning myself, but . . .

The nominal capacity is 32.6 kWh, not 33.6 kWh. The total buffer is therefore only (32.6-28.9)/32.6 x 100% = 11.3%.

Even allowing for rounding, you therefore can't have a bottom buffer of 11.5% unless there were no top buffer (which there is).

Seems like a glitch in the app.
 
Well, I'll give my 2 cents. On day one my SOC Low was 11.5% while SOC High was 100%. 32.6kWh x 88.5% = 28.9kWh. The low buffer never really changes, but the high buffer has been as low as 89.3% on my car if I haven't done enough balancing lately.
 
Darrell Hayes said:
Well, I'll give my 2 cents. On day one my SOC Low was 11.5% while SOC High was 100%. 32.6kWh x 88.5% = 28.9kWh. The low buffer never really changes, but the high buffer has been as low as 89.3% on my car if I haven't done enough balancing lately.
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Based on that, "high" = % of 28.9 kWh but "low" = % of 32.6 kWh. IOW, despite the same units they're not on the same scale.

If so, they should really be considered "% of max available" and "% permanently reserved", with the latter including both top and bottom buffers.
 
I see it less of a kWh buffer and more of a voltage operating range per cell. If a cell is operating at 93.2 Ah, then to get the gross battery from 96s0p cells, it would be an average voltage of 3.65V per cell (93.2 * 3.65 * 96).

When it comes to DCFC I believe the F56 is around 125A so the voltage can max out at 4.15V per cell (398.4V x 125A = 49.8kW). So the ratio of 3.65V/4.15V is pretty close to 28.9kWh/32.6kWh. Maybe some rounding differences, etc.
 
I have not used any specific apps for tracking the battery. This week I tracked what the car told me from a full charge though.

Distance driven - 109.5 mi
Battery charge remaining - 23%
Average efficiency - 4.8 mi/kWh

109.5 / 4.8 =22.813 kWh used

So 22.813 / (1-.23) =29.627 kWh total capacity.

I am not unhappy with that after 3 years and 32,000 miles.
 
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The problem is that the Mini has no idea about where you are going or other conditions. It only looks rearward and bases it on your last drive. I can drive 7000’ up a mountain and it always reads wrong. It really has no intelligence. I just look at battery percentage. It would be like your phone saying there is 2 hours of battery life. Since it doesn’t know if you will be doing video streaming or gaming, it just states a percent.

Some cars look at upcoming terrain, wind, rain, speed, battery degradation, temperature, etc and can do a more realistic estimate.
 
SameGuy said:
Has anybody set a correction factor on their GOM?
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I haven't user bimmercode or actually physically changed anything, but I have a factor of 140%. It is easy to use - double the gom, double again, the divide by 10. This is the extra you get. Eg:
GOM reads 100km, double 200, double again 400, divide by 10, 40, so the actual range is 140km. Very accurate actually.
 
I meant in the service menus where BC reset and roller mode hide. My BC does vary the GOM with conditions, but is consistently between 15 and 20% conservative.

Quiet Mini said:
Some cars look at upcoming terrain, wind, rain, speed, battery degradation, temperature, etc and can do a more realistic estimate.
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I don't need hyper-accuracy, I'd just like to correct by a more consistent factor. When I unplug from a full L2 charge, and it shows me 100 miles, I know for sure I can do around 120 miles. We don't generally jump from winter to summer immediately, so I'd just like to put in the correction factor of about 20%.
 
Resurrecting an old thread. When you balance your batteries, how long does this take? I read a great article
from Australia about balancing, but they never mentioned how long this takes and how to tell when complete.
I am limited to L1 charging, and normally stay in that 80% as the owners manual states. I do occasionally
have access to an L2 charger, and I will top up to 100%.
 
Busdriver said:
Resurrecting an old thread. When you balance your batteries, how long does this take? I read a great article
from Australia about balancing, but they never mentioned how long this takes and how to tell when complete.
I am limited to L1 charging, and normally stay in that 80% as the owners manual states. I do occasionally
have access to an L2 charger, and I will top up to 100%.
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I'm glad I have an old 2021 SE, from before MINI read about Tesla's 80% recommendation (where else would they get that idea?). IMO, if MINI was serious about 80%, they would have added a way to automatically stop charging at 80%.
 
insightman said:
I'm glad I have an old 2021 SE, from before MINI read about Tesla's 80% recommendation (where else would they get that idea?).
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I don't believe that you can blame Tesla. It's just battery chemistry in general.

For example, to extend battery life my Pixel 8a phone provides the option to limit charging to 80%. It will then only charge to 100% every 1-2 weeks* to avoid any "memory effect".

I don't have an iPhone, but I think it provides a similar option. In fact, I believe that Google Android is the follower here, after complaints of short battery life of Apple phones led to development of a comparable feature.

*Perhaps a hint of how often the OP should charge to 100%?? Doesn't really speak to how long, though.

Me, I basically charge my SE as much as I think I might need to for the next few days, then charge to 100% occasionally to balance the battery (or when unplugging early would require getting up in the middle of the night). That means it mostly cycles between ~45 and ~85%, but with wide variation, and I really don't worry about it. The rest of the car will wear out/get old (especially the tech) long before reduced battery capacity is really a concern.
 
CuriousGeorge said:
I don't believe that you can blame Tesla. It's just battery chemistry in general.

For example, to extend battery life my Pixel 8a phone provides the option to limit charging to 80%. It will then only charge to 100% every 1-2 weeks* to avoid any "memory effect".

I don't have an iPhone, but I think it provides a similar option. In fact, I believe that Google Android is the follower here, after complaints of short battery life of Apple phones led to development of a comparable feature.

*Perhaps a hint of how often the OP should charge to 100%? Doesn't really speak to how long, though.

Me, I basically charge my SE as much as I think I might need to for the next few days, then charge to 100% occasionally to balance the battery (or when unplugging early would require getting up in the middle of the night). That means it mostly cycles between ~45 and ~85%, but with wide variation, and I really don't worry about it. The rest of the car will wear out/get old (especially the tech) long before reduced battery capacity is really a concern.
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I didn't really think that after 2 years of telling SE owners to charge to 100%, MINI discovered that other manufacturers were suggesting 80% charging and simply copied that advice.

Before MINI joined the 80% crowd, I assumed the SE's designers knew that telling prospective buyers to charge an EV with 110-mile EPA range to 80% (resulting in a paltry 88-mile range) would be a non-starter. Unless the designers were completely clueless about EVs (which they weren't after making the MINI-E and BMW i3), I believe they had two choices:
  1. Design a large top-end buffer so charging to 100% would actually be charging to 80% of the battery's true capacity
  2. Include a software option to automatically stop charging at 80% and guilt-trip owners into using tha option
However, as we know, the company whiffed (perhaps no designers were involved), taking a third option: just tell owners to charge to 80% without giving them an easy way--or even suggesting a hard way--to charge to 80%.

@Puppethead has been charging to 100% for more than 100K miles with no adverse effects. Unlike the Chevy's massive burden with their Bolt, MINI has not had to replace thousands of battery packs due to premature failure.

The big top-end buffer theory seemed plausible until 2022, when MINI changed their 100%-charging advice to 80% advice without any explanation--or accommodation--whatsoever.
 
The 80% "rule" is totally driven by Tesla. Not only were they the first successful EV company, but they chose to expose most of the battery capacity to the end user. MINI's approach (inherited from BMW's i3?) was to add a big enough buffer and set 100% SoC to something closer to Tesla's 80% SoC. With over 100,000 miles on my SE and charging to 100% SoC every day for 4.5 years without loss of range I can confidently say the "80% rule" is little more than folklore.

Now it's likely different makers' battery handling is not uniform, so I'd go by the owner manual recommendation. But I can't explain what MINI did with the SE other than commit some sort of cut-and-paste error from BMW user manuals. What's actually needed is some actual scientific analysis, especially considering how EV battery technology (not to mention cooling, et al) have changed in the 17 years since the Tesla Roadster was introduced.
 
Puppethead said:
The 80% "rule" is totally driven by Tesla. Not only were they the first successful EV company, but they chose to expose most of the battery capacity to the end user. MINI's approach (inherited from BMW's i3?) was to add a big enough buffer and set 100% SoC to something closer to Tesla's 80% SoC. With over 100,000 miles on my SE and charging to 100% SoC every day for 4.5 years without loss of range I can confidently say the "80% rule" is little more than folklore.

Now it's likely different makers' battery handling is not uniform, so I'd go by the owner manual recommendation. But I can't explain what MINI did with the SE other than commit some sort of cut-and-paste error from BMW user manuals. What's actually needed is some actual scientific analysis, especially considering how EV battery technology (not to mention cooling, et al) have changed in the 17 years since the Tesla Roadster was introduced.
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As all owner are crying about range why you buy an SE you should know how you use a a car for your benefit as @Puppethead is a best example on a forum and as I’m driving very little 5000 miles a year is a best looking EV I can drive r for mine needs as I’m going to drop dead in this car
 
Puppethead said:
The 80% "rule" is totally driven by Tesla.
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Maybe in the EV world, but I have been using expensive battery powered equipment with non-replaceble (or at least not easily replaceable) Li batteries since before the turn of the century. It's always been known that they last longest when kept "half full", and only fully cycled occasionally to avoid any memory effects.

As for the SE's buffers, based on stated specs they can't be any larger than 11.3% total.

IOW, "100%" has to be at least 88.7%.

ETA: To what extent might MINI's changed advice be driven not by battery longevity, but by potential fire risk (liability)?
 
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CuriousGeorge said:
To what extent might MINI's changed advice be driven not by battery longevity, but by potential fire risk (liability)?
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I'd say zero chance, since MINI actually has a fire risk software update. The 80% rule in the later MINI SE manauls has absolutely no explanation other than careless editing. If it were legitimate MINI would give us a way to control the charging limit. "Unplug the car at 80%" would be ridiculous advice.

By the way, since it's summer-like weather I can now confidently say the fire risk software update has had no impact on my SE's charging or range.
 
22650 km, and battery capacity is 99.76 Ah. (Battery temperaure at 15.62 C). I always charge to 100% (L1 - 16A, 220V), and leave the car to balance the cells. I'm not sure, but somebody told me that the balancing starts after 4 hours of idle. By charging to less than 100, you are stressing the weaker cells and therefore minimizing the overall battery capacity. Just plug it after arrival and leave it on the charger.
 
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