Battery replacement, BMW or?

Dunno about AGM ones but generally it's the voltage off charge that's of interest. 14.2v basically means the alternator is working and the battery isn't open circuit.

A good lead acid battery will fall back to about 12.6v off charge. As it starts sulphating up this drops towards 12 or high 11s. The voltage then (or the rate of change of drop) is all the computer can measure, nothing magic.

Saying that, 7 years isn't bad for a fair weather car. Even work long, daily trips, 10/12 years is about the best achievable. My second battery in the 320d died an early death due to lack of use in COVID and not thinking to put it on charge quick enough. And I am paranoid about battery care!
 
The easiest way to see if the battery is any good at all, is if start / stop still works. On my son's 140, that was the first thing to no longer kick in and that was about 2 months before the battery warnings came on.
 
Thanks for the replies.

Used the car last night and this morning and the battery warning messages have disappeared :?

I did notice yesterday when I pulled the car out for the AA chappie I didn't notice the battery warning nessage but just thought I'd missed it but they've definitely gone for now so will see.

The AA chappie did test to see if the battery was holding its charge and it tested good.

This morning the CTEK was indicating fully charged,
20230614-094254.jpg

I understand if it the error light is lit and doesn't get past stage 2 on the staus lights the battery is past it and if the error light is on and it stays on stage 5 then the battery isn't holding its charge.

Will see how it goes, haven't tried stop/start as never use it but will try it next time and see if it works, thanks for the tip.

Just thinking with the hot weather combined with using the CTEK alot the IBM on the car was giving a false message on battery status or threw a wobbly. The CTEK should take this into account through the charging cycles during hot and cold weather.

Tim.
 
I would not rely on the CTEK status though. I have the same on the Golf battery, and it always shows 100% fine and on the service a few weeks back, the VW dealer said that the battery was in a very poor condition and needed replacing (they offered to do it at some rather inflated price ...)
 
pvr said:
I would not rely on the CTEK status though. I have the same on the Golf battery, and it always shows 100% fine and on the service a few weeks back, the VW dealer said that the battery was in a very poor condition and needed replacing (they offered to do it at some rather inflated price ...)
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You're talking about a franchised dealer though ££££s :lol: partly why I didn't want to go to them in the first place for the battery to be honest, not that I don't trust them :|

It's a difficult one but at the moment the AA testing seems to match what the CTEK is saying or vice versa. I was quite impressed with the AA chap as he was honest and mentioned he wouldn't fit a new battery if the test results are indicating the battery on the car is good, he said I would be ripping you off otherwise. Which is honest to be fair.

I'll probably break down tomorrow :rofl:

Tim.
 
Ive been getting these messages on my 335 - so I went out this morning and taking pvr’s advice tried the stop start test.
It didn’t work properly. The car cabin fan doesn’t want to switch itself off and the cabin fan speed won’t adjust.

Thd air con has decided to start blowing warm air from the drivers side vents.

I hope it’s a battery problem !

I have a Bmw warranty on this car and the Z so I think I will call assist after lunch

It’s either the Battery or an ECM - The Battery is about 6.5 yr old

Ps I don’t intend to hi Jack your thread Tim - it’s just there are so many fault similarities
 
ronk said:
Ive been getting these messages on my 335 - so I went out this morning and taking pvr’s advice tried the stop start test.
It didn’t work properly. The car cabin fan doesn’t want to switch itself off and the cabin fan speed won’t adjust.

Thd air con has decided to start blowing warm air from the drivers side vents.

I hope it’s a battery problem !

I have a Bmw warranty on this car and the Z so I think I will call assist after lunch
Click to expand...

Thanks Ron, keep us posted how you get on.

I'll try the stop start next time I'm out and see if it works. Everything else on the car is working normally including comfort access which I think is one of the first to stop working with battery issues.

When I got the warning above saying battery was discharged and certain functions have been switched off ie air conditioning etc it was all still working as normal which has got me thinking the messages were false or theres possibly an intermittent fault with the intelligent battery module that's on the battery, they can go faulty on BWWs as a bit delicate giving false warnings so will ask for it to be checked come service time.

I didn't really want to spend nearly 300 quid on a new battery if its testing ok and its possibly another issue throwing the warning messages 🤔

Tim.
 
My Stop/Start didn’t seem to function properly this morning.

There’s what seems to be a cabin fan running with no key etc - the system won’t shut down.
With this in mind I gave BMW Breakdown a call and they are comming out this evening
 
My Stop/Start didn’t seem to function properly this morning.

There’s what seems to be a cabin fan running with no key etc - the system won’t shut down.
With this in mind I gave BMW Breakdown a call and they are coming out this evening
 
ronk said:
My Stop/Start didn’t seem to function properly this morning.

There’s what seems to be a cabin fan running with no key etc - the system won’t shut down.
With this in mind I gave BMW Breakdown a call and they are coming out this evening
Click to expand...

Hope it's sorted Ron.

Tim.
 
Well my 335 Battery draw isn’t a failing Battery!

The heating & vent system is controlled by a box of tricks and seven (?) stepper motors linked in series and controlled by LBus (I t think that’s what he said) and there are 61 codes recorded on the motors and 62 on the box of tricks

The car goes into the dealership tomorrow and hire car is waiting. It’s no simple fix apparently. Dashboard out !
He said quite emphatically- do not let them do a re set of the codes - there is a system fault!

Here’s hoping you have a Duff Battery.
Now that’s something you normally wouldn’t wish on someone!!!
 
ronk said:
Well my 335 Battery draw isn’t a failing Battery!

The heating & vent system is controlled by a box of tricks and seven stepper motors linked in series and there are 61 codes recorded on the motors and 62 on the box of tricks

The car goes into the dealership tomorrow and hire car is waiting. It’s no simple fix apparently. Dashboard out !
He said quite emphatically- do not let them do a re set of the codes - there is a system fault!

Here’s hoping you have a Duff Battery.
Now that’s something you normally wouldn’t wish on someone!!!
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Good to have a diagnosis :D and look on the bright side having an extended warranty :)

Looked at my warranty yesterday and realised I'd opted for £250 excess to keep the monthlies lower, I must have thought back in 2019 what could possibly go wrong :lol:

Tim.
 
I also have a £250 excess with a £422 premium
From memory the zero excess policy is circa £750 so it’s simple to work out which is the better deal!

As a post script to this part of my part of the battery saga. The BMW insured warranty have been 1st class - so if you do have a problem other than a failing battery the will help.
Indeed, the seem to have got me to have got me to the front of the queue at the dealership tomorrow.
 
ronk said:
I also have a £250 excess with a £422 premium
From memory the zero excess policy is circa £750 so it’s simple to work out which is the better deal!

As a post script to this part of my part of the battery saga. The BMW insured warranty have been 1st class - so if you do have a problem other than a failing battery the will help.
Indeed, the seem to have got me to have got me to the front of the queue at the dealership tomorrow.
Click to expand...

I have the Comprehensive cover which I think is around £41 per month, I only really took it out when I heard how much a new engine costs, think it was 13k :o Kinda glad I did take out the warranty as there's reports of injectors failing on 2016 and early 2017 builds with the B58 engine which can cause engine failure and potential hydrolocking from fuel flooding the bores. BMW haven't officially recognised it as an issue but have revised the injectors. I know some owners of 2016/17 cars have swapped the injectors out, cost around £600 plus fitting ontop :| but I see alot of failures are on modified cars but there has been some stock engine failures.

Hoping the battery issues or lack of it has gone away now but might just ask if the dealer can scan for any codes come service time.

Tim.
 
pvr said:
The easiest way to see if the battery is any good at all, is if start / stop still works.
Click to expand...
Sorry but that is a terrible idea. The S/S functions on all modern cars require a raft of criteria to be met before the S/S will operate.
There is no way of telling whether any, or all, of those criteria have been met by 'the system' from the driver's seat.
 
Pondrew said:
pvr said:
The easiest way to see if the battery is any good at all, is if start / stop still works.
Click to expand...
Sorry but that is a terrible idea. The S/S functions on all modern cars require a raft of criteria to be met before the S/S will operate.
There is no way of telling whether any, or all, of those criteria have been met by 'the system' from the driver's seat.
Click to expand...

As a starting point it could be a first indicator all isn't well as the Intelligent battery monitor will most likely trigger certain functions to be switched off including stop/start, air con etc.

Tim.
 
I just this week fitted this battery:
https://www.tayna.co.uk/car-batteries/bosch/s4011/
Took the old one out, plonked this one in and Bob's your Uncle!
No coding.
 
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