kgosi_f30_340i
Member
Yep had the tracker removed 2 weeks ago just in case that was causing the issue.
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Read the WELCOME ALL BMWFANATICS post.
F30 340i won't start, even with perfect battery
- Thread starter kgosi_f30_340i
- Start date
TurboLlew
Honorary ///Member
As far as I can tell with your posts so far, you have not actually been charging the battery in between these incidents. You come back to the car later and it starts? (ie: car isn't moving ruling out wiring moving around, battery hasn't been charged so it rules out something draining your battery). That means nothing has drained the battery and it is likely an intermittent fault with one of the cells. If you drive the car to the battery centre it might be at a time that the faulty cell is good enough to start... that load test should be done when the car is in one of its 'moods' where it isn't starting in that case.
In your first post you mentioned attempting to start it drops the battery voltage (and it wouldn't start) that would imply that there is demand placed on the battery which it can't deliver (so not really the intermittent fault on wiring).
How old is the battery?
kgosi_f30_340i
Member
Just something to clarify
On the last incident where it began the issue of not starting again on its own power, I boosted it and drove it home. When I got home the car said the battery is very low. When I checked the battery was sitting on 11.8v. I then took my home battery charger, charged the battery up to 12.4v and attempted to start the car. Car did not start. I then took the battery out the car and went to battery center to see what’s going on. Didn’t drive the car there.
The battery is relatively new. It was bought March 2023 and is still under warranty. Was checked thoroughly and all apparently is well with it.
I am assuming the battery is not getting charged when driven. The reason I assume this is because when it was working fine I had charged it to full and drove it a few times over a period of 3-4 days. Until well it started giving issues again.
When the car is on I am getting just over 13.4 volts on the battery so I assumed this means the battery is charging under the power of the car. But maybe that’s where my problem lies and maybe that voltage reading is not accurate to “charging”.
I am thinking i need to get the alternator tested to ensure it is actually charging the battery when the car is running so it is not using up the battery instead. I did text all the fuses and saw that nothing is draining the battery in that regard.
TurboLlew
Honorary ///Member
A dying or dead battery on a modern car can cause strange things to happen. Not impossible for it to be a factory fault on the battery. Would they be willing to fit a new or loan battery to test whether this resolves the issue? The battery tester itself is not 100% foolproof when it comes to this. It is going to be frustrating ripping into different parts of the car chasing down a problem that turns out to be the battery.
On another note, was the battery coded/registered when it was bought? It would tell the car what voltage and current to use to charge the car (that Intelligent battery thing I mentioned before). You might be on to something in terms of the voltage being correct but it not actually delivering 'amps' to charge the battery? (I am not sure here since I don't know a lot about the IBS apart from knowing that's the reason you register the battery when you change it so speculating).
kgosi_f30_340i
Member
I did get the battery coded but it might be worth coding it once more to see if this fixes the problem.
Will also enquire on changing out the battery with a loan one and see if this ends up being an issue again. Thanks for the ideas
kgosi_f30_340i
Member
In a turn of events I ended up booking in the car because I couldn't find the problem. The problem ended up being that the positive cable was loose 😭😭😭😭 I kept my eye on the negative and trying to ground it properly and ensure they are both connected to the battery properly but didn't check the positive which was looks on the body. So sometimes it would have proper contact and sometimes not which is why it was intermittent. Also because of the inconsistent connection to the battery, the battery would not get properly charged and thats why it would lose voltage. I am kinda angry at myself because this is the most stupidest problem that I had to pay labor for. But happy it is now fixed.
Thank you so much everyone for the help with this. Learnt a lot in the process.
Thank you so much everyone for the help with this. Learnt a lot in the process.
kgosi_f30_340i
Member
I should've just checked all the wires not just the negative. It's a really stupid mistake.
Nastaliq
Well-known member
Its a weird one, I would say check the Tracker. On my previous car I had similar issues which could not be diagnosed. Turned out to be the Tracker unit itself that was draining the battery when parked, AND it was intermittent. So it would come and go, some times for weeks, car would be fine, then all of a sudden, not.
Secondly, I experienced an issue on my current car where the battery was draining when not being driven during Covovo times. The first time i went to BMW, they said battery is fine, its your tracker, but that sounded like bullshit, but sometimes its best to let people arrive at conclusions themselves. So they charged it over nights, and I collected it in the morning. Car was fine for 2 weeks then the issue started again.
All their charging metrics all came clear. The battery was then removed from the car to find 2 cells were completely dry, i am talking like powder dry.
Based on the dry cell, they replaced the battery at their cost (under MP), and I have never had an issue thereafter.
Secondly, I experienced an issue on my current car where the battery was draining when not being driven during Covovo times. The first time i went to BMW, they said battery is fine, its your tracker, but that sounded like bullshit, but sometimes its best to let people arrive at conclusions themselves. So they charged it over nights, and I collected it in the morning. Car was fine for 2 weeks then the issue started again.
All their charging metrics all came clear. The battery was then removed from the car to find 2 cells were completely dry, i am talking like powder dry.
Based on the dry cell, they replaced the battery at their cost (under MP), and I have never had an issue thereafter.
