[HighlandPete]

My understanding, it's also the battery State of Health (SoH) that is being monitored and charging strategy modified as the battery ages.

A new battery requires the registration to 'reset' the battery management.

[Craig-SM]

Originally Posted by HighlandPete

My understanding, it's also the battery State of Health (SoH) that is being monitored and charging strategy modified as the battery ages.

A new battery requires the registration to 'reset' the battery management.

Nothing as complicated as that, just charging parameters based on the capacity of the battery.

I recently removed the original battery as it wasn’t charging enough for the stop/start to work. A battery load test prior to repair showed it to be in bad health. 4 days later on the recovery cycle on a Noco G15000 and it now shows in good health. If there was such a program to monitor the health and create a charging strategy on the car then it failed miserably. Most likely as I stated previously to maintain a charge level on the battery with minimal engagement of the alternator for fuel economy

[t5pilot]

Originally Posted by Craig-SM

Not sure about Bimmerlink but you can on Carly. If you replace like with like then you don't need to register the battery.

Sorry, but that's just plain wrong.
A new battery, regardless of "like for like" should be registered in the car so that battery management is optimised.
It's not just a BMW thing either. Same applies to other manufacturers whose systems use intelligent battery management.

[Craig-SM]

Originally Posted by t5pilot

Sorry, but that's just plain wrong.
A new battery, regardless of "like for like" should be registered in the car so that battery management is optimised.
It's not just a BMW thing either. Same applies to other manufacturers whose systems use intelligent battery management.

Batteries are damaged by keeping them at a lower state of charge (SOC) as this this allows sulfation to develop. Sulfation creates a situation where the battery capacity is reduced in terms of amps but still shows full voltage. The longer this happens the worse it gets until you can no longer provide the amps required to start the car

This is from another forum and describes how the alternator charges the battery. I believe it was written by HighlandPete

Sorry for not getting back to 'batteries' before this evening. Has been another hectic day. Won't go into the details, but since Friday we've had a family emergency to deal with.

Back to BMW's energy management and battery charging.

Most of us are used to charging systems where we can charge a battery to 100% SOC (State Of Charge) and the charging will have a lot of flexibility, to more or less keep a decent battery close to 100%, until the battery performance starts to tail off with age. Winter driving make take a bit of a toll, due to extra energy demands, even normal use for some drivers may lower the SOC.

BMW's Intelligent alternator control (IGR), has a completely different charging strategy. To quote BMW; "In contrast to conventional charge control, the intelligent battery control avoids a 100% charge. The charge level of the battery reaches about 70 - 80% of the maximum possible charge".

IGR uses three different states of charge, IGR-Low, Medium & High, depending on the battery SOC. A more conventional charging strategy only applies when the battery is in a lower (predetermined) SOC. The energy management is designed to restrict charging to conditions like over-run, (loosely termed braking regeneration), when battery charging and when energy recuperation is possible, without using engine power. Higher voltage and/or partial alternator off-load/relief is used to maintain and restrict charging. A lot of the time the alternator is only charging to accommodate energy demands in the driving phase, nothing to charge the battery. Energy management is allowing for over-run charging, to "top up" the battery past the 75 - 80% SOC.

Easy to see how we can possibly have a driving profile, where we never get past the 80% SOC mark. Winter time we may not even achieve that level of charge, too much energy consumer demand, too little driving time, not enough over-runs, to charge the battery. I find that with my typical use. In winter time, there is high energy demand, trips too short, too many starts, to keep at 80% SOC or higher. Batteries are not as efficient in cold temperatures, just make it worse for some users.

The occasional use of a smart charger, like the CTEK range, can make a lot of sense. The charging time before the CTEK moves from bulk to the absorption phase, at about 80%, indicates how much we are below the BMW threshold of ~80% SOC.

To reverse sulfation you need high voltage, low amp pulses of charging over an extended period. The high voltage, low amps can be easily created but not the extended period. Add to that a charging system designed for fuel economy as described above and its not an intelligent battery management system designed to look after the battery. Instead it monitors the condition of the battery and allocates what systems can use the resources available, this normally starts with switching off stop/start and other high consuming systems with the aim of keeping enough power in reserve so when you press the start button, it does.

If the intelligent battery management worked to protect and prolong the life of the battery then why is the charging system damaging to a battery? Secondly, a battery that wouldn’t allow the stop/start to work, even after a charge and a long drive but after the same battery was recovered on an intelligent battery charger it now works fine?

Both charging and monitoring systems are designed to increase fuel economy and decrease emissions as a result. Both of which would save more money in fuel and taxes than the cost of a battery over its lifetime, even if shortened under the charging system.

[tjlees]

tbh the biggest battery killer has been the pandemic.

The number of friend/relatives that have had to replace batteries is significant. My friend's Merc MPEV battery died due to lack of use costing over a £1000 to sort.

my 335D has had no problems over the last 100k miles and 6 years, but the last year of use means it stays connected to my optimate 6 to ensure the battery is conditioned/desulphated properly.

I've just ordered a optimate solar (duo solar if you have a lithium battery) so i can leave it anywhere, given I'm unlikely to snap back to 15k pa.

may as well buy a charging point and a proper EV ...

[psp888]

I put my car on charge last week and charged it full. After 3 long journeys start stop wouldn't work. Today I put the charger back on, but this time on repair mode, after 4 hours repair finished, then I put it onto normal charge again for 6 hours. went out for a drive and start stop works again!! Fixed!

[tjlees]

Yep standard chargers or tickle chargers don't really work with agm batteries.

I managed to cause my agm race battery to bow out by leaving it connected to 300ma trickle charger over winter

man toys rule ...

[t5pilot]

Originally Posted by Craig-SM

Batteries are damaged by keeping them at a lower state of charge (SOC) as this this allows sulfation to develop. Sulfation creates a situation where the battery capacity is reduced in terms of amps but still shows full voltage. The longer this happens the worse it gets until you can no longer provide the amps required to start the car

This is from another forum and describes how the alternator charges the battery. I believe it was written by HighlandPete

To reverse sulfation you need high voltage, low amp pulses of charging over an extended period. The high voltage, low amps can be easily created but not the extended period. Add to that a charging system designed for fuel economy as described above and its not an intelligent battery management system designed to look after the battery. Instead it monitors the condition of the battery and allocates what systems can use the resources available, this normally starts with switching off stop/start and other high consuming systems with the aim of keeping enough power in reserve so when you press the start button, it does.

If the intelligent battery management worked to protect and prolong the life of the battery then why is the charging system damaging to a battery? Secondly, a battery that wouldn’t allow the stop/start to work, even after a charge and a long drive but after the same battery was recovered on an intelligent battery charger it now works fine?

Both charging and monitoring systems are designed to increase fuel economy and decrease emissions as a result. Both of which would save more money in fuel and taxes than the cost of a battery over its lifetime, even if shortened under the charging system.

What an in-depth reply.... none of which related to my quoted post, which simply stated that a new battery should be registered with the car...

[HighlandPete]

I think there is a bit of a crossed conversation going on here.

How a battery deteriorates and its longevity under energy management, is a different point than a new 'unregistered' battery and how energy management may not give the optimum charging and longest life cycle.

It's known a new 'unregistered' battery can have a short life, whereas the original battery lasted a good few years longer. The difference... not following the guidance to reset the system to a new battery.

[un1eash]

BMW refused to replace a battery on my old E92 under AUC warranty as they kept saying it was charging and fine even though after 2 weeks of use stop/start would fail along with the clock, heated rear window etc.
They even tried to register it as a new battery to get the car to charge it more, they didn't like the fact I knew this as Carly shows a history of battery registration and it shows they must of suspected a fault.

[Craig-SM]

Originally Posted by t5pilot

What an in-depth reply.... none of which related to my quoted post, which simply stated that a new battery should be registered with the car...

Your quote said that it had to be registered. No why’s or how, just that’s it’s plain wrong.
I asked you two questions, neither of which you have answered so assume you’re unable to

[NanasBack]

Summary:
If you fail to register a new battery (eg. capacity like for like), the system will only charge the new one to a reduced capacity (<80%) because of the IBS age degradation charge curve. Depending on the age of the original battery, the new one may never be charged above 50% capacity. (I don't know what the curve is). Sulphation degradation will be very high.

Conclusion:
To prolong the life of a new 90AHr battery, register it as a 110AHr device.
The system will 'over-charge' it, but in reality, instead of that being normally 80% charged, it will be 97% charged.

That will reduce the long term sulphation and hence, prolong the life of the battery.

[Craig-SM]

Originally Posted by HighlandPete

I think there is a bit of a crossed conversation going on here.

How a battery deteriorates and its longevity under energy management, is a different point than a new 'unregistered' battery and how energy management may not give the optimum charging and longest life cycle.

It's known a new 'unregistered' battery can have a short life, whereas the original battery lasted a good few years longer. The difference... not following the guidance to reset the system to a new battery.

I know you are trying to say they are two separate systems. One that uses the least amount of charging by having the alternator working when the car is on over run or braking instead of taking power away from the engine when providing power to propel the car. A great way of improving fuel economy. The other designed to look after the health and longevity of the battery.
The downside is the battery never becomes fully charged and any spare capacity is open to sulphation. The longer this happens the harder it is to remove these crystals without damaging the battery further.
The only argument I’ve heard so far is the battery needs to be registered so the intelligent battery management knows it is new. The management will then change the way the battery is charged as it ages. The problem is now you have had years of the battery kept to SOC of around 80%. The voltage still reads good but the amp hours are reduced and can’t be recovered without some kind of recovery. The recovery is from high voltage charging to flake the crystals off the plates where it can then dissolve back into the electrolyte. Continuous high voltage charging damages the plates though as well as creating heat that evaporates the electrolyte so it needs to be done in short pulses. The alternator can produce the higher voltage as it is normally reduced the regulator and having the charge pulsed is easy enough to do too.
This doesn’t happen though as myself and many others have recovered batteries that the car is saying isn’t serviceable and prevents stop/start from working. After recovery they work fine and as it’s the same battery surely the system is still treating it as an old battery therefore supposedly changing the charge program to suit, when in fact the recovery has it performing with the capacity of a much younger battery.

My argument is the intelligent battery management system isn’t about looking after the health of the battery otherwise you wouldn’t be able to recover one that the car says requires charging. I think the system is to maintain the ability to start the car as the battery becomes more damaged by turning other high demand systems off.

[HighlandPete]

Originally Posted by Craig-SM

My argument is the intelligent battery management system isn’t about looking after the health of the battery otherwise you wouldn’t be able to recover one that the car says requires charging. I think the system is to maintain the ability to start the car as the battery becomes more damaged by turning other high demand systems off.

There are certainly compromises going on with energy management, something we have to live with.

Also depends how we are looking at the function of battery management. If it is to work as an economy 'mechanism', it way well be doing a good job, the best it can under the design brief and application.

I agree it may not be the best for a battery, but what is the 'reduced' life cycle are we talking about? A couple or years less, if so, compared to what? Some AGM batteries in the current applications are lasting longer than lead acid batteries in conventional charging systems.

What you have stated about battery degradation, (which I don't disagree with), also emphasises to me how important registering is, to get a more 'aggressive' (if it's the right term) charging regime for a new battery, extending its useful life, compared to not registering it.

[Craig-SM]

Originally Posted by HighlandPete

There are certainly compromises going on with energy management, something we have to live with.

Also depends how we are looking at the function of battery management. If it is to work as an economy 'mechanism', it way well be doing a good job, the best it can under the design brief and application.

I agree it may not be the best for a battery, but what is the 'reduced' life cycle are we talking about? A couple or years less, if so, compared to what? Some AGM batteries in the current applications are lasting longer than lead acid batteries in conventional charging systems.

What you have stated about battery degradation, (which I don't disagree with), also emphasises to me how important registering is, to get a more 'aggressive' (if it's the right term) charging regime for a new battery, extending its useful life, compared to not registering it.

As I stated earlier the cost to the battery life is repaid and more from the fuel and tax saving from the energy management. It’s a compromise but the benefits are obvious.

Battery management and any aggressive charging it is supposed to do as the battery ages is of minimal benefit as it doesn’t work. It allows the sulfation to occur and the long periods of time required to reverse this at a high charge rate aren’t available in a car even on continuous charge if the energy management allowed it.

It’s not just AGM batteries that will suffer this problem but any lead acid ones. I don’t think changing the energy management to suit the battery is the-way forward, it is just a consequence of running the engine more efficiently. Maybe the answer is in Lithium batteries but these have their own issues as well let alone the additional cost.

[Tony 420I]

Originally Posted by psp888

I put my car on charge last week and charged it full. After 3 long journeys start stop wouldn't work. Today I put the charger back on, but this time on repair mode, after 4 hours repair finished, then I put it onto normal charge again for 6 hours. went out for a drive and start stop works again!! Fixed!

Mind if I ask what charger your using? looking at getting one myself... cheers

[Craig-SM]

Originally Posted by Tony 420I

Mind if I ask what charger your using? looking at getting one myself... cheers

I’d recommend a Noco Genuis 10 or Ctek MXS10. Both very similar in operation and performance, prices around £120-130.
If you have a motorbike and need to charge that too then go for the 5 amp versions of either as 10 amps is a bit high for little batteries.

[t5pilot]

Originally Posted by Craig-SM

Your quote said that it had to be registered. No why’s or how, just that’s it’s plain wrong.
I asked you two questions, neither of which you have answered so assume you’re unable to

It's been covered already.
If a new battery doesn't or shouldn't need to get registered with the car, manufacturers wouldn't tell you to do so. It's absolutely nothing to do with how you maintain an existing battery... which will of course have been registered correctly.
You are informing people that a new battery doesn't need registering. Which is wrong, and the point of my original reply.

[psp888]

Originally Posted by Tony 420I

Mind if I ask what charger your using? looking at getting one myself... cheers

https://www.amazon.co.uk/AUTOXEL-Mai...B0E16QAJAFB31M

I got this one, cheap and does the job.

[Craig-SM]

Originally Posted by t5pilot

It's been covered already.
If a new battery doesn't or shouldn't need to get registered with the car, manufacturers wouldn't tell you to do so. It's absolutely nothing to do with how you maintain an existing battery... which will of course have been registered correctly.
You are informing people that a new battery doesn't need registering. Which is wrong, and the point of my original reply.

Not answering the two questions and just resorting to the manufacturers said so.
BMW also tell me my gearbox is sealed for life, I guess that’s gospel too

[t5pilot]

Originally Posted by Craig-SM

Not answering the two questions and just resorting to the manufacturers said so.
BMW also tell me my gearbox is sealed for life, I guess that’s gospel too

FFS! It's not rocket science.
The manufacturer states (as I quoted) that a new battery SHOULD be registered.
You're telling people it doesn't matter.
Reasons for registering have been covered.
Hopefully anyone having a new battery, having read this thread, will side with the advice of BMW & have it registered.

[greatbm]

Originally Posted by t5pilot

FFS! It's not rocket science.
The manufacturer states (as I quoted) that a new battery SHOULD be registered.
You're telling people it doesn't matter.
Reasons for registering have been covered.
Hopefully anyone having a new battery, having read this thread, will side with the advice of BMW & have it registered.

+1 well said