Anyone keeping track of the battery's soh

My capacity regain didn't show until the pack had been been cycled after a float.

 

Last night's float charge put my battery up to 99% and 96.5Ah from 96.3Ah mid week.
It was on charge about 6 hours total, floating about 2 1/2 hours.
I'll keep up with weekly floats until it stops regaining capacity.

 

So, we have two SEs. One has over 10k miles on the odometer, the other just around 1,000. Recurrent says they have 95/110 miles remaining capacity, and 92/110 miles respectively. Both are at the bottom of the ranking as compared to other SEs.

Also bought a 5 year old BMW i3 with 36k miles that sat for months at 0% SoC. They rated it at the very top for battery health, better than new.

/confused

 

I believe that recurrent reports estimated range, not SOH. One of you is having a little more than the other.
The electrified app for Android can access SOH from the car.

 

Oh, well if it’s using the GOM range estimate it’s as useless as the GOM, which is extremely useless. Weird though that we’re still absolute bottom of the pack compared to other identical cars. Hmm.

 

I recently plugged in a BT OB2 adapter using the mi3 app on iPhone to my 23 w/3k miles. It showed SOH at 98%. My mom’s 22 w/9k showed the same. Not sure how accurate this is.

 

While this tread is active I have a question in a similar vein. I just got my car last week and the dealer told me that I should keep the level 2 charge speed at reduced to save the battery but that kind of defeats the purpose of level 2 because it makes it so slow. Is this true? Is it really saving my battery or is it just limiting the power just in case the electrical can’t handle it? Which mine can we have overkill with 100 amp service to a 50 amp plug.

 

I think your dealer is confused. The SE's Battery Management System will never ask for more power than can be safely used to charge the battery. You don't need to worry about that; the car will take care of itself.

The reduced charging speed means your SE will ask for less power from the EVSE plugged into it, as a way of protecting the electrical supply from an EVSE that may ask for more power than the circuit it's plugged into can safely provide (should be 80% or less of the total available current).

For example, the level 1 EVSE that came with my 2021 pulls a maximum of 10A and is not configurable. If I plug it into a 15A circuit, it's safe to allow the SE to ask for full power--the EVSE will only provide 10A. However, if that 15A circuit has other loads on it drawing a lot of current, it would be a good idea to reduce the charging speed on the SE.

A properly-configured EVSE won't supply any more power than safely allowed for the circuit it's on, regardless of how much power your SE asks for. As long as your level 2 EVSE won't ask for too much current from the circuit it's connected to (either through configuration or by installing one that has a maximum supply capability at 80% or less of the circuit it's connected to), you don't need to mess with the SE's charge speed setting.

As long as the EVSE you install will pull no more than 40A from that 50A plug, you are good to go.

 

Yeah that was my exact thought when he said that! I was like this doesn’t make any sense but then again he has only sold about 20 SEs. I just wish they would be little less misleading if they don’t know what they are talking about. Thank you for the help!

 

I have found that many (but not all!) sales people (of cars or otherwise) are reticent to say “I don’t know”. Instead, they either make up an answer and say it with confidence, or answer a different question from what was asked.

The best answer they could give is “I don’t know, but let me find out for you”. It is truly refreshing when I am told that.


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There's also a lot of confusing information out there about charging to 80%, because that's how Tesla decided to do things and they created the modern EV market. Another factor is the SE's charge speed is so low (max 50 kW DC) that it doesn't stress batteries like other EVs might that can go over 100 kW.

MINI decided to keep things simple and have the car do all of the necessary battery protection automatically, so for the SE it's: Always Be Charging. I have over 47,000 miles on my SE and I always charge at max rate, am not seeing any range degradation. I don't know what my SOH is, but maybe I don't want to know at this point .

 

The daily/trip charge limit scheme is the best compromise between maximizing the available battery capacity and and battery longevity. The first Leaf recommended the 80% cap in 2012. Current Teslas are 90% or no limit depending on chemistry, while virtually all other EVS recommend a range from 70-90%. The MINI is really the odd man out here, even BMW recommends 80% for optimal battery life. Funnily enough my 2023 MINI SE manual recommends 80%.

On the other hand, a ridiculous amount of people ignore the limits because they "paid for the car." I wouldn't want to buy one of those second-hand, much like I wouldn't want a car from an owner that ignored oil changes.

 

When someone tells me something I know is just BS, I wonder what else I've been told that was also BS. Great way to lose my trust in someone. Best way for them to lose a sale. ECS just lost a sale because instead of either answering my question or saying "I don't know", they bullpooped me. I'm now also less likely to shop for other items with them. Being able to do business without unnecessary hassle is worth paying extra for. Returns are a PITA...

Battery charging intensity is usually measured as the 'C' rate. 1C would fully charge a battery in 1 hour.
Level 2 charging at max rate is still mild for a LiIon battery, ~0.25C
DC charging (1.3C) frequently could wear the battery a bit. That's could, not will. I just use it when I need to and don't worry too much. Level 2 at as high as it will go is my preference.

 

Here is where my SE landed in 6 months of checking SOH at the end of every month. Still seems to be dropping rather rapidly. At this pace I'll be getting a new battery when the car reaches about its 4th B-day.
date mi capacity(Ah ) SoH
6/27/2022 50 97.2 100
7/31/2022 445 96.4 99
8/27/2022 1010 95.8 98
10/2/2022 1875 95.5 98
11/4/2022 2454 94.7 97
11/30/2022 2837 94.8 97
12/30/2022 3222 93.6 96

 

What exactly is SOH measuring? And how is it measured?


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I'm not exactly sure, but its probably something like current capacity / initial capacity. I read it out on the Electrified app, but I'm not sure what the SE is doing to measure it.

 

So, the battery remembers how many electrons it was able to store on day 1, then subtracts the number of electrons stored today, and calculates the percentage of current capacity?

As inaccurate as the GOM is, I’d be hesitant to believe anything the battery tried to tell me.

Is this SOH data coming from the SE, meaning BMW designed it. Or is the SOH data coming from a 3rd party?


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The most important question: Is this the same value BMW/MINI uses to determine if you get a new battery?

 

A 50A outlet should be on a 50A breaker. A 100A breaker is not safe, legal or a good idea. Swap the breaker for a 50A one. Wiring needs to be either 6g or 8g, depending on how it is run and how warm an environment it will be in.
A mini will pull a max of 32A. I believe some other BEVs can pull up to 80A. Over 40A needs to be hardwired. I personally have a hard wired 48A EVSE on a 60A circuit with 4g wiring. All correctly sized. I went large for possible future options. The breaker must always be sized to the weakest part, which in your case is the 50A outlet.

 

Checking in here. I checked my battery when the recent freeze hit, as with some possible power disruption, I switched from just I before I leave charging to always charging. Electrified reported 94Ah, before I did that. 95.6Ah after about 4 days of mostly being on charge at 100%. Weirdly, it was 97% SOH both times. I have about 5600miles on my July 23 SE.