[pmcmtnbkr]

Okay so long story short I have been using Bimmerlink to monitor oil temp boost pressure battery voltage ect. I noticed a few months ago that it also had a battery charge % under the battery icon along with being able to register the battery. Has anyone else regularly checked charge%. I havent had any battery problems and it regularly shows anywhere from 90% to low 60% charge. I can start the car check the voltage have a reading of 65% do nothing to the car get in it a few hours after parking it and have a reading of 85%. There seems to be no rime or reason to the odd charge % reading I can go from a temp controlled building 50 deg showing 60% charge drive the car to work about 8 miles check the charge and it might show 65% park the car in 25 deg temp all day get in it and have a charge% in the high 80s. I thought this could be a neat tool to get an Idea of when to replace the battery, but appears to be no better than licking a 9 volt battery to see if it has a charge. Has anyone played with this I sent an email to Bimmerlink and never got a response. As near as I can tell this is the original battery to the car and is going on 6 years old.

[MarcoZandrini]

I highly recommend you replace the battery if it could be, in any way, the original battery. Batteries, as you know, don't like cold weather. Cold temps slow down the batteries chemical reactions. Try Autozone or Walmart. Then get it registered.

[pmcmtnbkr]

Originally Posted by MarcoZandrini

I highly recommend you replace the battery if it could be, in any way, the original battery. Batteries, as you know, don't like cold weather. Cold temps slow down the batteries chemical reactions. Try Autozone or Walmart. Then get it registered.

Thats just it it has no indication of issues no slow cranking in extreme cold voltage is just fine, starts right up even after prolonged radio use without the car running. No random low voltage issues all the things that would happen when a battery is on its last legs. It just Bimmerlink showing odd charge % readings it makes no sense. I am not in the habit of just replacing things that don't need to be

[damianbmw12]

Originally Posted by pmcmtnbkr

Thats just it it has no indication of issues no slow cranking in extreme cold voltage is just fine, starts right up even after prolonged radio use without the car running. No random low voltage issues all the things that would happen when a battery is on its last legs. It just Bimmerlink showing odd charge % readings it makes no sense. I am not in the habit of just replacing things that don't need to be

Originally Posted by pmcmtnbkr

Thats just it it has no indication of issues no slow cranking in extreme cold voltage is just fine, starts right up even after prolonged radio use without the car running. No random low voltage issues all the things that would happen when a battery is on its last legs. It just Bimmerlink showing odd charge % readings it makes no sense. I am not in the habit of just replacing things that don't need to be

6 years it needs to replaced. Bimmerlink has great support. You might want to check in with them.

[lateapex'er]

Funny you ask, I had the same results when checking my battery life. My battery was 6 years old and still showed 77%. I ended up replacing it anyway due to its age and registered via the BimmerLink app. At first, it read 99% then after sitting showed 93%. Oddly enough after going for a drive it never went back to 99% but hovers around 97/96%. I figured this was normal and never paid attention to it again.

I hear you on not replacing parts if they work fine. I replaced mine this past summer, due to its age and with winter approaching I'd rather not be stranded. Was able to get my local dealer to price match an out-of-state dealer with the lowest price.

[pmcmtnbkr]

So still on the original battery 2 winters later still no issue with slow cranking no start have load tested the battery several times everything checks okay. I happened to be in touch with bimmerlink on another issue i finally got some sort of answer on the odd state of charge and here it is
SG Software GmbH & Co. KG <support@bimmercodeapp.com>
Thu 4/21/2022 4:19 AM
Hi,
the state of charge is calculated by the IBS in the car and the internal calculation is unknown unfortunately.
--
Kind regards / Schöne Grüße
Stephan Gauch
So I guess that answers the question this is an unreliable calculation. So do what makes you feel good about your battery, changing it out by this reading alone seems like a bad idea.and waste of $$$ So for me I will continue running this battery until it starts giving me a reason to change it. For those interested I continue to get state of charge readings from 65% to 85% for no rhyme or reason. I even coded a friends BMW when he changed out his battery to an H8 and his car registered a state of charge of 75% on a brand new fully charged battery.

[pmcmtnbkr]

So one last thought for this post. After chasing a cold start idle issue i had unplugged the battery for an extended period of time something like 2hrs while i was doing other things since that reset Bimmerlink has been reading a state of charge of 98 to 99%

[nazali]

TBH, I do one of 2 things

1> use Solar BA9 to check all aspects of the battery and charging
2> Ista, which has EVERYTHING, from 5 days charges, highs and lows

Knowing the charge is only one part of the story you need to know

SOC & SOH

you can have a good charge on a crap battery or a crap charge on a good battery, they determine wether you just need to charge or when to replace

voltage and charge of the battery by it's own is of no real use when diagnosng, also dont forget the alternators ability to charge the battery

[nazali]

this is FAR more important or relevant as a diagnostic tool, I am pissed of with my car and its electrical battery consumption, but the plus side is inbuilt info like this,
BMW is a car you both want to Fuq 7 ways to sunday and be Fuq off with if you get my drift

[nazali]

n

[2una]

Originally Posted by nazali

this is FAR more important or relevant as a diagnostic tool, I am pissed of with my car and its electrical battery consumption, but the plus side is inbuilt info like this,
BMW is a car you both want to Fuq 7 ways to sunday and be Fuq off with if you get my drift

Where are you getting that readout info you posted from please?

[nazali]

from ista