[Bal s t]

Hi chaps needs some help again,had a yellow battery warning on my 3 series saying, ‘battery seriously discharged start engine or use external charging’ so plugged in bimmerlink and battery percentage was at 38,so disconnected it and put a charger on,went back to car about 30-40 minutes later and it said fully charged,plugged bimmerlink back in and it was still showing 38% which was strange took it for a drive and it only went upto 41% does this mean the battery is done or do i need a different charger?the weird thing is i did the same for the wifes 4 series and battery was showing 58% put that on charge after full charge the reading came back as 99%

[danb1979]

Sounds like it's time for a new battery

Easy enough to do yourself; just get a battery via Tayna betteries

I've just fitted their Exide AGM battery to my F31 - £150 delivered and took me about 20mins after faffing with the clamp that holds it down as there's not enough room for my fat hands where the battery's located in the touring

Registered the battery and that's it done

I left it on the CTEK charger for 24hours beforehand though to give it a good charge and then after a few days, connected the car to the CTEK charger too as it's hardly being used currently

[Bal s t]

Originally Posted by danb1979

Sounds like it's time for a new battery

Easy enough to do yourself; just get a battery via Tayna betteries

I've just fitted their Exide AGM battery to my F31 - £150 delivered and took me about 20mins after faffing with the clamp that holds it down as there's not enough room for my fat hands where the battery's located in the touring

Registered the battery and that's it done

I left it on the CTEK charger for 24hours beforehand though to give it a good charge and then after a few days, connected the car to the CTEK charger too as it's hardly being used currently

Thought that might be the case,£150 sounds a good price my dilemma is my car doesn’t get driven much probably a 1000-1200 a year,the battery is the original from 2018 and only on 38k is there any way to charge the battery with a better charger?or could i re register it as new battery at higher amp to get it charging again?

[danb1979]

Originally Posted by Bal s t

Thought that might be the case,£150 sounds a good price my dilemma is my car doesn’t get driven much probably a 1000-1200 a year,the battery is the original from 2018 and only on 38k is there any way to charge the battery with a better charger?or could i re register it as new battery at higher amp to get it charging again?

Once the battery starts to go that's it done; needs to be changed

If you use your car so little then you need a decent trickle charger (CTEK) to keep it healthy and make sure that you take it for an Italian tune up every so often too

This is what I've fitted:

https://www.tayna.co.uk/car-batteries/exide/ek950/

It's 'like for like' against the original 90Ah BMW battery; so it just needs registering to the car

You don't need a bigger battery

[Bal s t]

Originally Posted by danb1979

Once the battery starts to go that's it done; needs to be changed

If you use your car so little then you need a decent trickle charger (CTEK) to keep it healthy and make sure that you take it for an Italian tune up every so often too

This is what I've fitted:

https://www.tayna.co.uk/car-batteries/exide/ek950/

It's 'like for like' against the original 90Ah BMW battery; so it just needs registering to the car

You don't need a bigger battery

Battery ordered gone for the same one you have,my local guy quoted me £249 for a battery for mine thats nearly a ton difference 🤦🏾*♂️which ctek charger do you have?since I’m spending might aswell get a charger while my bank cards out already🤣

[danb1979]

Originally Posted by Bal s t

Battery ordered gone for the same one you have,my local guy quoted me £249 for a battery for mine thats nearly a ton difference 🤦🏾*♂️which ctek charger do you have?since I’m spending might aswell get a charger while my bank cards out already🤣

This one:

https://www.amazon.co.uk/CTEK-Start-...39&sr=1-1&th=1

There's a £7.90 off as well; make sure you tick the box before you order

[Bal s t]

Originally Posted by danb1979

This one:

https://www.amazon.co.uk/CTEK-Start-...39&sr=1-1&th=1

There's a £7.90 off as well; make sure you tick the box before you order

Sorted will be here tomorrow.thankyou for the help and advice.👍🏾

[SkyJawa]

I'd go with this, same-ish price but 5.0A instead of 3.8A, its what I and a lot of others have and recommend

https://www.amazon.co.uk/CTEK-Batter...ve%2C61&sr=1-1

[danb1979]

Originally Posted by SkyJawa

I'd go with this, same-ish price but 5.0A instead of 3.8A, its what I and a lot of others have and recommend

https://www.amazon.co.uk/CTEK-Batter...ve%2C61&sr=1-1

That's what I had but it died.. The new one I've got does a great job; hence why I recommended it

[SkyJawa]

I wasn't saying theres anything wrong with it, no need to be defensive just offering a different opinion and option! I have 2 MXS5, they do a great job too, hence the recommendation or are alternatives not allowed to be posted and you have to go with the first thing someone posts?!

[danb1979]

Originally Posted by SkyJawa

I wasn't saying theres anything wrong with it, no need to be defensive just offering a different opinion and option! I have 2 MXS5, they do a great job too, hence the recommendation or are alternatives not allowed to be posted and you have to go with the first thing someone posts?!

Sorry pal not being defensive; just saying that the one I recommended works well and it's more aimed at our AGM batteries

The MXS 5.0 is a great charger; sods law mine just stopped working (still have it so will see if I can open it and see what's what)

[SkyJawa]

[ade555]

Sorry to hijack this thread but been monitoring my battery over last couple of weeks. I can go by voltage readings or what bimmerlink is saying, as I don't drive for longer the 30min that inc let's say start the car in morning to defrost for 5-10min.
I think the battery took some beating, bimmerlink will say SOC of 70-78 depend on day, voltage would very from 12.2 -12.4 during normal weekly use. SOC is fair bit lower if car don't get used for over 24h, down to 53. You can tell battery is on low side simply by hearing how the car turns over if stood over 24h.


My head is saying battery had enough but with this silly IBS system I sort of wanted to make sure before I spent. I also connected NOCO charger last weekend to pump some juice to it,removed battery out the car. Originally showed SOC 99 but it wasn't fully charged, now week later down to 70. SOC is not a problem but voltage of 12.2-12 is on low side.

Jumped in car went shopping with wife, left car running, got back home. About 30min driving and 30 min idle. Voltage car running 14.7-15.00 once turned of 13.2, 30 min later 12.2 😬

Battery is still original and done well, 7 years so can't complain but I do wonder if I let the battery fully charge will it hold?

[danb1979]

Originally Posted by ade555

Sorry to hijack this thread but been monitoring my battery over last couple of weeks. I can go by voltage readings or what bimmerlink is saying, as I don't drive for longer the 30min that inc let's say start the car in morning to defrost for 5-10min.
I think the battery took some beating, bimmerlink will say SOC of 70-78 depend on day, voltage would very from 12.2 -12.4 during normal weekly use. SOC is fair bit lower if car don't get used for over 24h, down to 53. You can tell battery is on low side simply by hearing how the car turns over if stood over 24h.


My head is saying battery had enough but with this silly IBS system I sort of wanted to make sure before I spent. I also connected NOCO charger last weekend to pump some juice to it,removed battery out the car. Originally showed SOC 99 but it wasn't fully charged, now week later down to 70. SOC is not a problem but voltage of 12.2-12 is on low side.

Jumped in car went shopping with wife, left car running, got back home. About 30min driving and 30 min idle. Voltage car running 14.7-15.00 once turned of 13.2, 30 min later 12.2 😬

Battery is still original and done well, 7 years so can't complain but I do wonder if I let the battery fully charge will it hold?

Mine was the original 2015 battery

I was down to 51% according to Bimmerlink; so it was the right time

Also we've just had some cold weather; it's going to come back too from what the forecasters are saying

So I'd say for peace of mind; get the thing swapped out toot-sweet and then you're on a good footing then Your battery will not get any better TBH; only worse and short runs aren't good; so deffo plan a few Italian tune-ups in there too

Give it a good 1-2 days on trickle first and then fit it if you can as you never know how long it's been sat on a shelf before you get it etc

[ade555]

Originally Posted by danb1979

Mine was the original 2015 battery

I was down to 51% according to Bimmerlink; so it was the right time

Also we've just had some cold weather; it's going to come back too from what the forecasters are saying

So I'd say for peace of mind; get the thing swapped out toot-sweet and then you're on a good footing then Your battery will not get any better TBH; only worse and short runs aren't good; so deffo plan a few Italian tune-ups in there too

Give it a good 1-2 days on trickle first and then fit it if you can as you never know how long it's been sat on a shelf before you get it etc

Can't see other option been honest, I'm sort of amazed how long it lasted. I ordered leads for noco charger is well so can hardwire to engine compartment points and just easy to plug in is well. Might plug in the new battery ever two weeks or something just to make sure is getting proper charge.

Car still starts but you can tell after been stood is having a hard time. Most likely if left for longer wouldn't start.

[danb1979]

Originally Posted by ade555

Can't see other option been honest, I'm sort of amazed how long it lasted. I ordered leads for noco charger is well so can hardwire to engine compartment points and just easy to plug in is well. Might plug in the new battery ever two weeks or something just to make sure is getting proper charge.

Car still starts but you can tell after been stood is having a hard time. Most likely if left for longer wouldn't start.

Yeah I've got the eyelet fittings connected for my CTEK charger; just plug n play then etc

My F31 was starting fine; but you could just feel at times it took a little longer and didn't sound as sharp etc

I could also hear the folding wing mirrors when I unlocked the car; they were a little slower than I thought was normal

New battery in and they've sped up slightly and don't sound like they're straining etc and the car starts with a hard start now, if that makes sense

[Pond]

Originally Posted by ade555

Jumped in car went shopping with wife, left car running, got back home. About 30min driving and 30 min idle. Voltage car running 14.7-15.00 once turned of 13.2, 30 min later 12.2

If your battery is losing 1 volt over 30 minutes then it's knackered.

A fully charged good battery (at approx 14v) should drop to around 13v as soon as it's disconnected from the charger or the alternator (engine off). A healthy battery, even in cold weather, should not drop more than about 0.1v a day if connected to a car with no additional parasitic drain.

Everybody who owns a modern BMW should know they HATE even slightly defective batteries and throw their toys out without warning.

AGM batteries are no different to a 'normal' lead acid battery, with the exception they have an "Absorbent Glass Mat" which give them a higher amperage rating for a given size.

Batteries are cheap (relatively), diagnosis rates by a garage are not!

BTW CTEK maintenance chargers are very good, whichever amperage you plump for.

[TurboWeasel]

Yup /\

Over sensitive IBS systems are becoming a nuisance in EVs as well. A slight resistance discrepancy in a circuit and it throws a "Drivetrain fault" error and you're going nowhere. Usually a software update fixes that to back off the sensitivity a bit.

If there is any doubt, there is no doubt. Just replace it. Proactive replacement is better than waiting for outright failure and then being left stranded. 7 years is pretty good and about right. Ignore all the "Mine is 45 years old and still going strong" stuff as these claims never come with any context on how the car is used, or it's just flat out lies.

[ade555]

I fitted new battery about week ago now, been honest I have to stop looking at this SOC becasue it will drive me insane, took 28h on noco genius 10 to bring new battery to fully charge state and when cennected to car SOC showed 99%, registered new battery boom down to 80%, next morning 98%.

Benn monitoring this along with voltage ect., will jump anything from 90% to 98%. Today had nice long trip 3h one way in car, I was thinking perfect. Checked before trip 93% after trip 90% , honestly I just don't get it.

[Pond]

Originally Posted by ade555

I fitted new battery about week ago now, been honest I have to stop looking at this SOC becasue it will drive me insane, took 28h on noco genius 10 to bring new battery to fully charge state and when cennected to car SOC showed 99%, registered new battery boom down to 80%, next morning 98%.

Benn monitoring this along with voltage ect., will jump anything from 90% to 98%. Today had nice long trip 3h one way in car, I was thinking perfect. Checked before trip 93% after trip 90% , honestly I just don't get it.

It could easily be a 'non problem' TBH. The monitoring percentage will just be taking the voltage and comparing that to a 'fixed' nominal maximum.
If a battery has just been needed to power something quite big with a high amperage draw, the voltage will drop instantly.

But they 'recover' afterwards and the voltage will rise back up.

If you checked the voltage before starting the car (cranking the engine is by far the largest amperage draw on a car battery), then start the car, then shut it off and check the voltage instantly it will be scary low. Within seconds it will recover and increase to almost the previous level. It's just the way lead acid batteries work.

[ade555]

Originally Posted by Pond

It could easily be a 'non problem' TBH. The monitoring percentage will just be taking the voltage and comparing that to a 'fixed' nominal maximum.
If a battery has just been needed to power something quite big with a high amperage draw, the voltage will drop instantly.

But they 'recover' afterwards and the voltage will rise back up.

If you checked the voltage before starting the car (cranking the engine is by far the largest amperage draw on a car battery), then start the car, then shut it off and check the voltage instantly it will be scary low. Within seconds it will recover and increase to almost the previous level. It's just the way lead acid batteries work.

I'm aware regards draw when for example you start the car ect., what I can't understand after 3h drive SOC drops. Just don't make sense how the whole system works on BMW.
Voltage drop on cranking car over is not a problem on new battery as it stays above 11.6v vs old 10.4v then alternator kicks in to recharge after start. Most cars will just let voltage regulator to sort the voltage. This silly system in BMW is just pointless. Wonder who though that not letting the battery charge fully after long drive makes sense. Just bonkers, the way it should work let the car charge the battery to almost full then once it gets to that stage if it must then stop charging till the SOC drops to certain level again. I'm venting my frustration with the system more then anything else been honest.