[Aronis]

My battery is coming to end of life I guess. I get the "battery maintenance" warning more often despite fully charging it on this past weekend.

I am waiting on quotes from the dealer.

I had heard rumor that you can replace with a non Lithium ion battery? Less expensive?

Also heard rumor that the Li battery is WARRANTIED for 8 years? That may be BS.

Mike

[CFoote]

FYI, there are two batteries in the F90 chassis, so make sure both are done.

Yes, it sucks, but....

*****EDIT: The AUX battery (2nd battery) is on 540/550 models, sorry for the misunderstanding. It is usually located in the passenger side under the windshield cowl.

M5/M5C/M5CS use a high drain lithium ion battery in the trunk.

[Aronis]

Originally Posted by CFoote

FYI, there are two batteries in the F90 chassis, so make sure both are done.

Yes, it sucks, but....

WHAT???? Where is the other one? You jest?

Mike

[Used2be]

Originally Posted by CFoote

FYI, there are two batteries in the F90 chassis, so make sure both are done.

Yes, it sucks, but....

Please share with us the location of the second battery for the F90. And also share the source for your claim of two batteries. The only mention of a second battery that I’ve found is that use of the new lithium-ion battery allows for the deletion of an additional 12-V battery used for 24-V steering.

[Aronis]

"When retrofitting, a more powerful battery may be used. Standard batteries may always be replaced by AGM batteries with the same specifications.
When installing a battery of a different size or a different battery type, this change in vehicle data must be programmed into the vehicle data in accordance with specifications."

Waiting on information from dealer on this option. Change to less expensive battery and be done with it.

Mike

[Used2be]

Originally Posted by Aronis

Waiting on information from dealer on this option. Change to less expensive battery and be done with it.

Mike

I’ll be interested in the info your dealer gives you about replacing the lithium-ion battery with an AGM battery. The quote you post might be referring to those cars with lead acid batteries and not apply to the lithium-ion version. The monitoring system for the lithium-ion battery will have subtle differences from an AGM, and while they may be able to be coded it might also take some changes to physical wiring. Quiz your dealership carefully if they allow the change. It could turn into a can of worms.

I don’t have an EE degree, just guessing over the hints in the general vehicle electronics section for the F90. So take my warning with a grain of salt if you wish.

[FatRear08]

Originally Posted by Aronis

"When retrofitting, a more powerful battery may be used. Standard batteries may always be replaced by AGM batteries with the same specifications.
When installing a battery of a different size or a different battery type, this change in vehicle data must be programmed into the vehicle data in accordance with specifications."

Waiting on information from dealer on this option. Change to less expensive battery and be done with it.

Mike

I’m curious as to why your battery needs replacing after only 4 years. The lithium ones are lasting much longer than conventional batteries. Owners with 2015 M3/M4’s still on their original ones. Defect? If I’m not mistaken didn’t you have a non lithium charger hooked up at some point? Could’ve done some life shortening damage. Maybe I’m mistaking you with another member.

[Aronis]

Originally Posted by FatRear08

I’m curious as to why your battery needs replacing after only 4 years. The lithium ones are lasting much longer than conventional batteries. Owners with 2015 M3/M4’s still on their original ones. Defect? If I’m not mistaken didn’t you have a non lithium charger hooked up at some point? Could’ve done some life shortening damage. Maybe I’m mistaking you with another member.

That was after it already was giving me that warning message. I only charged for a couple hours. I got the correct charger and have used that three times. Perhaps the CPU just needs to be reset or something?

Rather put the correct battery back in than risk getting stuck somewhere with a dead battery. But for sure with a new battery, that trickle charger goes on monthly. Should have been a given from the get go. $2000 was what I was told in first quote. Crazy battery! LOL.

Mike

[FatRear08]

Originally Posted by Aronis

That was after it already was giving me that warning message. I only charged for a couple hours. I got the correct charger and have used that three times. Perhaps the CPU just needs to be reset or something?

Rather put the correct battery back in than risk getting stuck somewhere with a dead battery. But for sure with a new battery, that trickle charger goes on monthly. Should have been a given from the get go. $2000 was what I was told in first quote. Crazy battery! LOL.

Mike

Yeah Mike they’re not cheap. Hopefully maybe it is an internal reset and you’ll be good to go. No matter what type of driving I’m doing, I habitually hook it up and let it fully charge once every 3-4 weeks. Can’t hurt and I know it’s getting a full charge cycle. If it’s going to sit more than 2 days, I also throw it on the charger. Again, doesn’t hurt and keeps it topped off. Will it help in the long run, time will tell. Maybe.

[Demon Barber]

Originally Posted by CFoote

FYI, there are two batteries in the F90 chassis, so make sure both are done.

Yes, it sucks, but....

We need to hear more about this claim.

[CFoote]

Hey everyone,

Oh gosh! The sharks are circling! I appreciate everyone is anxious to learn more about the "AUX" battery.

So I just got my M5CS today and haven't had a chance to peek under the hood.

Looks like us M5 guys probably don't have the AUX battery given how quickly you all responded saying "SHOW THE PROOF!". The AUX battery is actually tucked under the passenger side windshield cowl on the 540 and 550 cars.

I'm sure the M guys took the battery out to save weight, but on the standard 540 and 550 there are two, or even three batteries depending upon the equipment ordered. For example, Adaptive Driving Suspension gets you the AUX battery. Integral Active Steering gets you the AUX battery. All depends on equipment ordered.

For those who asked for a source of this information, please refer to the BMW G30 technical training manual.

I'm actually VERY surprised BMW didn't install the AUX battery on the M5. How many of you have heard the loud cooling fan run for 10+ minutes after you shut off the car? This type of activity is what kills your battery. Replace every 4-5 years minimum.

Chris

[pbonsalb]

I was going to guess that the extra battery was for the G30 not the F90. Porsche does the same thing for active suspension — adds a second battery. But I think in Porsche’s it is a 48V battery.

[Used2be]

Originally Posted by CFoote

I'm actually VERY surprised BMW didn't install the AUX battery on the M5. How many of you have heard the loud cooling fan run for 10+ minutes after you shut off the car? This type of activity is what kills your battery. Replace every 4-5 years minimum.

It might have been more helpful, and less alarming given the expense of the new lithium-ion battery, to suggest the F90 could possibly have two batteries since the 540/550 G30 models do? Your flat FYI statement was so definitive and then you add the “Yes, it sucks” to enhance the surety of your claim. Apparently you hadn’t looked at an F90 M5, but just assumed it was the same as a G30 550?

To move onto your last statement that we need to replace our batteries every 4-5 years minimum. Where did you come up with that? I had an AGM battery in the 2013 F10 M5 and it lasted 6 1/2 years. I believe the lithium-ion batteries claim a longer life than AGM.

Congratulations on the M5CS though, everyone seems to love them.

[Maverik259]

Originally Posted by FatRear08

Yeah Mike they’re not cheap. Hopefully maybe it is an internal reset and you’ll be good to go. No matter what type of driving I’m doing, I habitually hook it up and let it fully charge once every 3-4 weeks. Can’t hurt and I know it’s getting a full charge cycle. If it’s going to sit more than 2 days, I also throw it on the charger. Again, doesn’t hurt and keeps it topped off. Will it help in the long run, time will tell. Maybe.

You're not supposed to "store" tool li ion battery's at 100%. I think 70-80% is what most the major tool brands recommend. Can't imagine it would be different for another application of the same technology. Shortens their life. Something to keep in the back of your mind.

Just my .02.

[Aronis]

My RS6 battery lasted 9 years and 132000 miles. New one was $214 in 2012.

My lawn tractor battery lasted 19 years. Lmao

Mike

[Demon Barber]

Originally Posted by CFoote

Hey everyone,

Oh gosh! The sharks are circling! I appreciate everyone is anxious to learn more about the "AUX" battery.

So I just got my M5CS today and haven't had a chance to peek under the hood.

Looks like us M5 guys probably don't have the AUX battery given how quickly you all responded saying "SHOW THE PROOF!". The AUX battery is actually tucked under the passenger side windshield cowl on the 540 and 550 cars.

I'm sure the M guys took the battery out to save weight, but on the standard 540 and 550 there are two, or even three batteries depending upon the equipment ordered. For example, Adaptive Driving Suspension gets you the AUX battery. Integral Active Steering gets you the AUX battery. All depends on equipment ordered.

For those who asked for a source of this information, please refer to the BMW G30 technical training manual.

I'm actually VERY surprised BMW didn't install the AUX battery on the M5. How many of you have heard the loud cooling fan run for 10+ minutes after you shut off the car? This type of activity is what kills your battery. Replace every 4-5 years minimum.

Chris

You said it so definitively without knowing, so thats why everyone was eager to hear more. A lithium battery should be able to handle 10 minutes of fan cooling just fine. Saying the battery should be replaced "every 4 to 5 years minimum" for a $1600 stock lithium battery sounds like you may be misinformed about the type of battery it has and/or its designed longevity.

[CFoote]

Originally Posted by Demon Barber

You said it so definitively without knowing, so thats why everyone was eager to hear more. A lithium battery should be able to handle 10 minutes of fan cooling just fine. Saying the battery should be replaced "every 4 to 5 years minimum" for a $1600 stock lithium battery sounds like you may be misinformed about the type of battery it has and/or its designed longevity.

Okay, let's have a candid discussion about the lithium battery then. How long do you think you should wait to replace it? And what is BMWs guidelines about it, and perhaps what are guidelines from other manufacturers?

I'm not misinformed at all, these cars have a HUGE drain on the battery with all the electronics and do you know how many amps those fans draw when they cool the engine down after shut off? I think it's great BMW put a Lithium Ion battery in the car to help circumvent the lack of a AUX battery, but given the draw on the electrical system and how quickly prior gen cars eat batteries - if you want to run the lithium until it fails one day, it certainly doesn't affect me it's just a inconvenience when it happens.

I'm proactive on maintenance and I know my locale (northeast US) challenges batteries with hot/cold with the seasons, not to mention the electrical draw from the car itself. It drives me crazy the entire iDrive/stereo system stays on when I press the start/stop button, and I'm usually quick to open the door so it doesn't shut off, so I have to open/close the door again to get the system to shut down.

Chris

[Mach550]

If it's similar to my M550i there is one battery under the cowl on the passenger side and one in the trunk. I haven't needed to replace mine and I've been driving it energetically since December of 2018.

[CFoote]

Originally Posted by Used2be

It might have been more helpful, and less alarming given the expense of the new lithium-ion battery, to suggest the F90 could possibly have two batteries since the 540/550 G30 models do? Your flat FYI statement was so definitive and then you add the “Yes, it sucks” to enhance the surety of your claim. Apparently you hadn’t looked at an F90 M5, but just assumed it was the same as a G30 550?

I have edited the post so no one is confused or misinformed...

Chris

[Demon Barber]

For those of us who have owned the previous F10 M5s with the same engine and same cooling fans running after shutdown, the AGMs lasted 4 to 5 years. Lithium batteries are well documented to endure more charge/discharge cycles than lead acid batteries, and also maintain strong output down to about 95% discharge, so it would be difficult to make a case for them needing to be replaced at the same frequency as AGM unless there are other factors involved. Based on AGM longevity, 6 to 7 years would be a more reasonable estimate of lifespan for lithium, maybe longer.

[pbonsalb]

Originally Posted by CFoote

Okay, let's have a candid discussion about the lithium battery then. How long do you think you should wait to replace it? And what is BMWs guidelines about it, and perhaps what are guidelines from other manufacturers?

I'm not misinformed at all, these cars have a HUGE drain on the battery with all the electronics and do you know how many amps those fans draw when they cool the engine down after shut off? I think it's great BMW put a Lithium Ion battery in the car to help circumvent the lack of a AUX battery, but given the draw on the electrical system and how quickly prior gen cars eat batteries - if you want to run the lithium until it fails one day, it certainly doesn't affect me it's just a inconvenience when it happens.

I'm proactive on maintenance and I know my locale (northeast US) challenges batteries with hot/cold with the seasons, not to mention the electrical draw from the car itself. It drives me crazy the entire iDrive/stereo system stays on when I press the start/stop button, and I'm usually quick to open the door so it doesn't shut off, so I have to open/close the door again to get the system to shut down.

Chris

If you want to preventatively replace $2000 parts, assuming the representation that is the cost of the lithium battery is accurate, go ahead. I do all the work on my cars and a lot of preventative maintenance (like rod bearings on my E90M3) but I think I will change a $2000 battery when there are signs it is necessary. I live in the Northeast as well and drive year round in weather that ranges from as low as -20F to as high as 100F. Hopefully there will be aftermarket options. Antigravity and others make lithium starter batteries now, but I don’t know whether they are the right size for the F90.

[CFoote]

I'm afraid the cost of the battery is part of owning these very expensive cars.

I know that modules can wreak havoc with low voltage and can potentially even damage some modules. What I will do, and probably what many other owners should do is invest in a load tester and that will help determine at what point the battery should be replaced.

Like you, I certainly don't wish to dish out big money on a battery but I also respect the engineering and design that went into the car. so I won't short-change any parts on this car or any of my cars.

So perhaps load testing the battery with a tester available online would help folks in determining when to do it. Unfortunately I've had a few batteries, despite constant trickle charging, just "go" and a charge is no longer maintained. Those are the tough days running around for a few hours getting the battery swapped out.