M4 G80 lithium ion battery issue
Discussion
I don't use my M4 regularly, as shown by the fact that it's 2.5 years old with 7,300 miles on the clock.
When not in use, it's in my garage connected to a CTEK trickle charger to keep the lithium ion battery in good condition.
Took it out yesterday (17/12) to get a routine brake fluid change and it gave me a "power error" issue and said I shouldn't turn it off. It cranked fine so I ignored as it was several hours before I was due at the dealership. When I went to take it there it also started fine and stop/start was also working OK on my 45 minute journey.
Got to dealership and mentioned the message. After brake fluid change they took a look and told me that the battery was knackered (not their words!). They ordered a new battery which they said would be with them by 19/12. Initially they didn't have a loan car so were going to pay for a taxi to get me home, must admit this was great service! They shortly after found me a load car due to a cancellation so all good in that aspect.
They weren't sure BMW would cover the cost of a new battery under warranty "due to low mileage". I also have the pre-paid service plan.
What's the collective's thought on how long a lithium ion battery should last when there is low usage of the car but battery kept charged on a trickle charger? My opinion is that the battery should still be fine. Am I wrong in thinking that?
When not in use, it's in my garage connected to a CTEK trickle charger to keep the lithium ion battery in good condition.
Took it out yesterday (17/12) to get a routine brake fluid change and it gave me a "power error" issue and said I shouldn't turn it off. It cranked fine so I ignored as it was several hours before I was due at the dealership. When I went to take it there it also started fine and stop/start was also working OK on my 45 minute journey.
Got to dealership and mentioned the message. After brake fluid change they took a look and told me that the battery was knackered (not their words!). They ordered a new battery which they said would be with them by 19/12. Initially they didn't have a loan car so were going to pay for a taxi to get me home, must admit this was great service! They shortly after found me a load car due to a cancellation so all good in that aspect.
They weren't sure BMW would cover the cost of a new battery under warranty "due to low mileage". I also have the pre-paid service plan.
What's the collective's thought on how long a lithium ion battery should last when there is low usage of the car but battery kept charged on a trickle charger? My opinion is that the battery should still be fine. Am I wrong in thinking that?
Thanks for responding. No, not teaching me to suck eggs, if I knew all the answers I probably wouldn't be asking here 
Not sure to be honest. Just the same trickle charger I had used previously on my Audi R8 V10+ which I'm guessing uses the same type of battery.
How do chargers for LI batteries differ from others?
Not sure to be honest. Just the same trickle charger I had used previously on my Audi R8 V10+ which I'm guessing uses the same type of battery.
How do chargers for LI batteries differ from others?
Some chargers and or maintainers are lithium specific or have the ability to be switched to lithium type.
Charging or maintaining a lithium battery with a non lithium charger is very likely to shorten the life of the battery.
I have a maintaining charger specifically for lithium, on motorcycles.
It actually can't do a regular lead acid battery.
Charging or maintaining a lithium battery with a non lithium charger is very likely to shorten the life of the battery.
I have a maintaining charger specifically for lithium, on motorcycles.
It actually can't do a regular lead acid battery.
Many lithium batteries won't take a charge when run down as they have a low voltage protection system that the charger needs to switch off.
You need the correct charger type, lead acid or agm charger won't work.
Which model ctek do you own?
You need the correct charger type, lead acid or agm charger won't work.
Which model ctek do you own?
Edited by 732NM on Thursday 18th December 22:42
cliffords said:
Some chargers and or maintainers are lithium specific or have the ability to be switched to lithium type.
Charging or maintaining a lithium battery with a non lithium charger is very likely to shorten the life of the battery.
I have a maintaining charger specifically for lithium, on motorcycles.
It actually can't do a regular lead acid battery.
CTek CS One.Charging or maintaining a lithium battery with a non lithium charger is very likely to shorten the life of the battery.
I have a maintaining charger specifically for lithium, on motorcycles.
It actually can't do a regular lead acid battery.
That's what's confusing. When I first started it after its long stay in the garage (probably a month) it cranked fine and started immediately. Same when a few hours later I drove it to the dealership. The stop/start also worked fine over the 45 minute drive.
So, don't understand why it needs a wake up when it seemed to be working fine however BMW are saying the battery is knackered.
Not criticising your comment - thanks for answering. Just... confused.
So, don't understand why it needs a wake up when it seemed to be working fine however BMW are saying the battery is knackered.
Not criticising your comment - thanks for answering. Just... confused.
I'm referring to the charger waking the battery up. It may be the battery was close to the low limit and driving it didn't get it charged enough and then it went into low voltage protection mode and needed a kick and full charge.
It would show as dead in those circumstances.
It's not unheard of for lithium batteries to refuse to charge with zero warning and be scrap.
It would show as dead in those circumstances.
It's not unheard of for lithium batteries to refuse to charge with zero warning and be scrap.
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