Anyone keeping track of the battery's soh

I've been taking a reading every month. This month's was not looking great

Screenshot_20231202-123543 by Darrell Hayes posted Dec 9, 2023 at 2:31 PM

SOC 89.9 - 11.5. I'm guessing this represents the top & bottom buffers. The 11.5 stays pretty consistent, but the 89.9 is the lowest it has been. SOH & capacity just keep dropping, but if you take into account that the buffer keeps growing, the overall capacity seems to stay the same at about 113 to 114Ah.
I've only done DC charging once & tend to keep the charge in the 50-80% range most of the time. I allow it to go to 100% and sit for a couple hours once or twice a month to rebalance. 1.5 years on the road & 9k mi. I'll be interested to see what Mini has to say when I bring it in in June for 2yr maintenance.
I did do a 98mi drive yesterday & had 24% left over, so that is still well over the 114mi range rating

 

I’ve found that my SoH seems to drop during periods where I don’t leave the car plugged in and recovers afterwards, but it takes multiple days of being plugged in. If SoH is based on charge balance, I’m guessing your battery is out of balance enough that leaving it plugged in for a couple hours doesn’t do much.

 

I guess I'll give that a try. I figured since the cell voltage range is only 0.01V, it was probably pretty well balanced, but maybe SOH has nothing to do with voltage range

 

My latest check. 30,174 miles. 26 months old. I have charged it since mid July. Going to give it a few days on charge.

Darrell, I was trying to keep max charge to 80-90, but also suffered capacity loss. After switching to full charges before I used the car, I regained some.

 

wow that is way beyond my latest reading. I'm only at 13.5k at 27 months. I haven't seen numbers like that since the 4th month. My numbers have stayed the same for about the last year. Going up to 100% a couple times a month helps. Generally keep it between 50 and 80%. I guess I could charge to full a bit more, but I really don't drive that far, so it would be sitting at nearly full charge a lot. Got home from a trip the other day at 1%, close call

 

After seeing my SOH take a dive, I switched to 100% charges. But I do them so it hits 100% a few hours before I know that I'm going to drive somewhere. I try to avoid leaving it at 100% for more than a few days. I need to check, but I have a feeling that I have a higher SOH than a year ago. It did take quite a few cycles to climb back up. Anyone who is borderline for a battery replacement at 8 years should avoid charging to 100%! You haven't run it low until you've driven 2 miles at -- I was down to about 3 bars by then.

 

97% battery health at 50.000 km charging always to 100% at home.
I’m using eFlow app from bimmercode guys

 

Ooh thanks for that. I forgot about eFlow. What is missing from the free version?

 

These screens are what you get with the free eFlow version, mini not plugged into charger. This is a 14,000 mile 3+ year old 2022 mini that is driven about 80 miles twice a week and charged overnight to 100%. On other days it may be driven a few miles around town but not charged until the day before these trips. You have to upgrade to see the EDME error as well as anything else. I don't see any errors reported by the Mini, dunno what the EDME error is. I'll have to look into it. Perhaps a way to get some money out of me .

 

Just checked mine again. It had a 100% charge after the last check, and sat for a day on charge. Today, I ran it down to 51%, then fully charged again as I need a full battery for tomorrow. It's been floating a couple of hours. I've gained another 0.2Ah, now 95.8. Mileage now 30241.

 

I fully charged my battery last night. With the car still plugged in, the charge light is not on. Is this new behaviour?

 

I believe that the light goes off after some while.

 

Indeed, after full charge the light eventually goes off while still plugged in.

 

9 months old, 12 000 km. and SOH 100% (Capacity 96.89 Ah). I always charge it to 100 using 16A, 220v. Once per month i do 6A slow charging.