[Processing61]

My e90 330d auto has an occasional/intermittent fault where it won’t start. Most of the time it cranks but will just fail to start. Pretty much every time it fails, you can start it after a while by taking the key out and back in to try turn on again and keep doing that until it starts. It differs in how long it takes to start and how many times it cranks, occasionally it won’t crank at all. It can happen when cold or warm.

It hasn’t failed on me just yet but sometimes now I’m having to try start the car nearly 10 times before it starts and don’t want to get to the point where I get stuck and then have to sort the problem.

Any advice on places to start troubleshooting/looking into? All I’ve looked at so far is the battery voltage which measured 12.15v after a 20 min drive and 11.8v after sitting for about 20 hours, does seem a little low but I’m not sure.

Any advice is appreciated, thank you.

[jacbo]

I would expect to see over 13V for the battery at idle. Ideally around 14V.

And over 12V when car is off

[Processing61]

Originally Posted by jacbo

I would expect to see over 13V for the battery at idle. Ideally around 14V.

And over 12V when car is off

Just checked idle, it was roughly 14.1v, idled for about 3 mins

So 11.8v off and 14.1v idle

[ValSolo]

11.8 is a bit low.
This thread might help you.

[therealdb1]

Sounds like the alternator is charging if you read 14V engine running but a properly charged battery should read more than 11.8V.
Until you can be confident in your battery it is not worth looking anywhere else.
First thing to check is that there is nothing drawing excessive current when the engine is off pulling the battery volts down. Not sure what you are reading the battery voltage with, or even if you are measuring at the terminals, but you will need an ammeter capable of reading a fair few amps. If there is nothing drawing amps (you will get some drain as switching off the ignition does not kill everything dead) then replace the battery and get it properly coded and registered to the car. Then do your checks again and read any fault codes with a BMW specific reader not a generic one and see how you get on.

[Processing61]

Originally Posted by ValSolo

11.8 is a bit low.
This thread might help you.

Thank you!

[Processing61]

Originally Posted by therealdb1

Sounds like the alternator is charging if you read 14V engine running but a properly charged battery should read more than 11.8V.
Until you can be confident in your battery it is not worth looking anywhere else.
First thing to check is that there is nothing drawing excessive current when the engine is off pulling the battery volts down. Not sure what you are reading the battery voltage with, or even if you are measuring at the terminals, but you will need an ammeter capable of reading a fair few amps. If there is nothing drawing amps (you will get some drain as switching off the ignition does not kill everything dead) then replace the battery and get it properly coded and registered to the car. Then do your checks again and read any fault codes with a BMW specific reader not a generic one and see how you get on.

Great, thank you. I checked to see if there was a lot of current drawn but it looks to be fine, so I think I will try replacing the battery.

Now, I checked the battery and currently it has a yuasa ybx 3000 battery https://www.gsfcarparts.com/971na0440?auto_apply_coupon=SHOP60&gclid=EAIaIQobC hMIkZutz4GJ8QIVyPZRCh084QTuEAQYASABEgLQDvD_BwE

From what I’ve read if I replace it with exactly the same battery, I will only have to do the “basic” coding, basically only to say that a new battery is in/register it with something like Carly or inpa
https://youtu.be/Qb5x9yLe8dA

Would this be correct?

[therealdb1]

If it is a straight swap, like for like, then yes you only need to register the new battery but while you have your diagnostic gear connected it makes sense to check that the car is coded for the correct battery type if you do not know who fitted the existing one.

[Processing61]

Originally Posted by therealdb1

If it is a straight swap, like for like, then yes you only need to register the new battery but while you have your diagnostic gear connected it makes sense to check that the car is coded for the correct battery type if you do not know who fitted the existing one.

Good idea, I will do that. Thanks again!

[Processing61]

Originally Posted by therealdb1

If it is a straight swap, like for like, then yes you only need to register the new battery but while you have your diagnostic gear connected it makes sense to check that the car is coded for the correct battery type if you do not know who fitted the existing one.

I don’t suppose you know if there are any guides to show me how I would be able to check which battery is coded on the car at the minute?

[Processing61]

So ive managed to get inpa working and it’s showing the current coded Ah is 90Ah. But looking in the boot the battery says “yuasa YBX 3000” which is stated as 95Ah. https://www.gsfcarparts.com/971na0220

So a couple of questions;

Is there a way I can find out the exact battery that I have? To make sure the above is correct. Or would the only way to be physically removing it and finding a part number or something.

Is it wrong that (if the battery I’m looking at online is the same as what I have in the boot) the battery days 95Ah and INPA is showing it’s coded for 90Ah?

Do I need to find out any other details if I end up wanting to purchase the exact same battery, to make sure I get the exact one? Just as I notice capacity, technology, CCA mentioned.

Thanks

[Processing61]

Also, I'm stuck between whether to go for the same lead-acid battery that's in the car or for a new AGM. Does anyone have some advice?

[Rich_D]

Those values do seem low, it shouldn't drop below 12v after only being sat for 20 hours and after 20 mins of driving I would expect to see more than 12.15v, which I assume you're checking as soon as you stop the engine?

Mine is a late 2010 car, original battery and hasn't moved for 5 days, just checked the battery voltage and it's 12.16v, no issues starting even if I leave it for a couple of weeks and the voltage won't really drop much lower than this.

The original BMW battery for a 330d is 90Ah and 900 CCA, so someone has fitted an aftermarket battery in yours, but it needs a new battery registering as you have IBS and changing to 95Ah, so that it can charge correctly.

I would get it charged on a proper charger and then drop tested, as it could be a weak / failing battery anyway and coding won't really help much if that's the case.

[Rich_D]

Originally Posted by Processing61

Also, I'm stuck between whether to go for the same lead-acid battery that's in the car or for a new AGM. Does anyone have some advice?

Stick to what was fitted originally, only later LCI cars with stop-start got AGM batteries and the E9X 330d never got stop-start, so go with lead acid IMO.

[Processing61]

Originally Posted by Rich_D

Those values do seem low, it shouldn't drop below 12v after only being sat for 20 hours and after 20 mins of driving I would expect to see more than 12.15v, which I assume you're checking as soon as you stop the engine?

Mine is a late 2010 car, original battery and hasn't moved for 5 days, just checked the battery voltage and it's 12.16v, no issues starting even if I leave it for a couple of weeks and the voltage won't really drop much lower than this.

The original BMW battery for a 330d is 90Ah and 900 CCA, so someone has fitted an aftermarket battery in yours, but it needs a new battery registering as you have IBS and changing to 95Ah, so that it can charge correctly.

I would get it charged on a proper charger and then drop tested, as it could be a weak / failing battery anyway and coding won't really help much if that's the case.

Yes, as soon as I stopped the engine.

I checked the current and the draw seemed fine so I have taken the old battery out and will be replacing it. It was leaking a little too so I think it's well needed, just in time.

I will replace it with the YUASA YBX 3000 019 (same as what I've taken out) and will code it properly.

Thanks!

[Processing61]

Originally Posted by Rich_D

Those values do seem low, it shouldn't drop below 12v after only being sat for 20 hours and after 20 mins of driving I would expect to see more than 12.15v, which I assume you're checking as soon as you stop the engine?

Mine is a late 2010 car, original battery and hasn't moved for 5 days, just checked the battery voltage and it's 12.16v, no issues starting even if I leave it for a couple of weeks and the voltage won't really drop much lower than this.

The original BMW battery for a 330d is 90Ah and 900 CCA, so someone has fitted an aftermarket battery in yours, but it needs a new battery registering as you have IBS and changing to 95Ah, so that it can charge correctly.

I would get it charged on a proper charger and then drop tested, as it could be a weak / failing battery anyway and coding won't really help much if that's the case.

Unless you would be able to recommend a better battery?

[Silver Streek]

I've used Yuasa batteries on a few cars and they are pretty good batteries, certainly no difference from a Bosch one.

[therealdb1]

Wouldn't bother with AGM unless you have stop start. You will not gain much in performance for the significant extra outlay to buy the thing.

I've been a recent convert to Exide batteries. Got one on my daily runner after a couple of other brands let me down a few months outside of the guarantee period and I fitted one to my wife's Smart car after the original fitment gave up the ghost after 12 years. Considering all of her journeys are less than 5 miles and she only does about 1500 miles per year the car still always starts on the button without any extra battery charging!
Only experience I have had with Yuasa is for alarm back up batteries and they are pretty good at that so no reason to doubt the quality of their car batteries.

[Processing61]

So I did actually end up going for a powerline 019 AGM battery. I went for it before I read these replies, lol.

There was a few things that I read and preferred in terms of performance with AGM (if correct) but the main thing was that the previous lead acid/flooded had began to leak and started corroding the surface of the metal (maybe to do with the car not being coded for this battery? Or very old?) , so I’ve treated the surface rust and painted it to protect. I’d rather there would be no chance of that happening again. It ended up being £25 more than the yuasa.

https://www.tayna.co.uk/car-batterie...iAAEgLLKfD_BwE

[therealdb1]

£25 is no big deal in the scheme of things. There was a time when AGM batteries were twice the price of conventional lead/acid.
You must make sure the car is told it has an AGM fitted as the two types have different maintenance charge levels. I have AGM batteries on my boat and the charger has a specific setting for this battery chemistry.
You should be able to code the car yourself as you have INPA but I have never had to do it so don't ask me how!

[Processing61]

Originally Posted by therealdb1

£25 is no big deal in the scheme of things. There was a time when AGM batteries were twice the price of conventional lead/acid.
You must make sure the car is told it has an AGM fitted as the two types have different maintenance charge levels. I have AGM batteries on my boat and the charger has a specific setting for this battery chemistry.
You should be able to code the car yourself as you have INPA but I have never had to do it so don't ask me how!

No problem! For sure. I used INPA, NCS Expert and NCS Dummy to code and check. The car is an 06 and apparently, its never had a battery change. It has, but I guess its never been coded/registered.

The battery I have is 95 Ah AGM and I did notice that there was no option for 95Ah when coding, so I selected 90Ah AGM. I have looked online and it seems like everybody else does this (is this right or wrong? haha). So I have coded that for now and will do a bit of digging/reading to check if this is ok or there is a way to access/add a 95AHh AGM option.

[therealdb1]

I would think what you have done is fine. Less chance of the car trying to overcharge your new battery if it thinks it is slightly lower capacity.
Chances are your old battery was being overcharged if it wasn't correctly matched to the charging system and was venting hence the "leakage" that you have noticed.