[Wellingtonz]

I'm looking to buy this 2014 320i N20 but there's a charge battery on the dash.

the fella says I need to drive it around and it'll charge.

scanned with bimmerlink and no permanent errors.

question is, will bimmerlink give a code out for a weak alternator?? or does a weak failing alternator won't throw a code?

[Billfitz]

This is all you need to keep track of the battery and alternator. https://www.amazon.com/Battery-Charg...%2C102&sr=1-27

Short drives are the #1 enemy of battery state of charge, so living in Singapore you may need to use a battery maintainer.

[Opie55]

Originally Posted by Wellingtonz

I'm looking to buy this 2014 320i N20 but there's a charge battery on the dash.

the fella says I need to drive it around and it'll charge.

scanned with bimmerlink and no permanent errors.

question is, will bimmerlink give a code out for a weak alternator?? or does a weak failing alternator won't throw a code?

Sounds like you need to use more features of Bimmerlink. Forget the code reading part. Among the many parameters you can monitor live with Bimmerlink is battery voltage both with the car running and the car off. Add battery voltage to the screen of live parameters (the "dashboard" Bimmerlink calls it)- you can select several - start the car and drive it. What does the voltage read while driving? If the battery is pretty low, I'd expect the live charging voltage to be as high as 14.8 volts, or therabouts. But with these intellignet alternators it can vary quite a bit. Sometimes mine can be low 13s or even low 14s for a while, but on balance it's high 14s. Your battery can only output 12.7 or so even if brand new, so numbers higher than that are from the alternator. Also add battery state of charge to the dashboard. That give you the percentage the battery is charged. Check it before and after a test drive. I'm sure it will increase due to the alternator charging the battery. Don't expect it to be near 100%. It's not supposed to be. Anything above the mid-70s is fine. Mid-80s is common.

[Opie55]

Actually, battery state of charge is not a parameter to add to the dashboard - it is on a separate screen where you register a new battery, so its' already there.

[Wellingtonz]

Originally Posted by Opie55

Sounds like you need to use more features of Bimmerlink. Forget the code reading part. Among the many parameters you can monitor live with Bimmerlink is battery voltage both with the car running and the car off. Add battery voltage to the screen of live parameters (the "dashboard" Bimmerlink calls it)- you can select several - start the car and drive it. What does the voltage read while driving? If the battery is pretty low, I'd expect the live charging voltage to be as high as 14.8 volts, or therabouts. But with these intellignet alternators it can vary quite a bit. Sometimes mine can be low 13s or even low 14s for a while, but on balance it's high 14s. Your battery can only output 12.7 or so even if brand new, so numbers higher than that are from the alternator. Also add battery state of charge to the dashboard. That give you the percentage the battery is charged. Check it before and after a test drive. I'm sure it will increase due to the alternator charging the battery. Don't expect it to be near 100%. It's not supposed to be. Anything above the mid-70s is fine. Mid-80s is common.

hello, I've been looking for a fellow bimmerlink user.

do you what values I can add to my bimmerlink app to monitor the alternator as well? I saw another post where this guy posted a screenshot of his bimmerlink sensor values and he had multiple " generator" values that's supposedly the alternator but I can't find any of them in my app!

well update, I bought the car earlier today (13th sep) because I told the guy if he could make the message disappear I'll buy it and apparently he drove around 50-60km to make it disappear ( apparently).

I'm getting suspicious thoughts like what if he just charged the battery before handing it over and it's slowly losing juice as we speak?! that being said I'm heading off(1am now) to do what you told me which is to monitor the volts etc.

cheers

[Billfitz]

Are you going to drive around all the time with your Bimmerlink hooked up? The meter I linked is always on, out of the way on your console. It shows both battery state of charge when you turn on the ignition without starting and the alternator output when the engine is running.

[Wellingtonz]

Originally Posted by Opie55

Sounds like you need to use more features of Bimmerlink. Forget the code reading part. Among the many parameters you can monitor live with Bimmerlink is battery voltage both with the car running and the car off. Add battery voltage to the screen of live parameters (the "dashboard" Bimmerlink calls it)- you can select several - start the car and drive it. What does the voltage read while driving? If the battery is pretty low, I'd expect the live charging voltage to be as high as 14.8 volts, or therabouts. But with these intellignet alternators it can vary quite a bit. Sometimes mine can be low 13s or even low 14s for a while, but on balance it's high 14s. Your battery can only output 12.7 or so even if brand new, so numbers higher than that are from the alternator. Also add battery state of charge to the dashboard. That give you the percentage the battery is charged. Check it before and after a test drive. I'm sure it will increase due to the alternator charging the battery. Don't expect it to be near 100%. It's not supposed to be. Anything above the mid-70s is fine. Mid-80s is common.

I forgot to add that the battery dated back to 2019. probably a weak batt?

[Wellingtonz]

Originally Posted by Billfitz

Are you going to drive around all the time with your Bimmerlink hooked up? The meter I linked is always on, out of the way on your console. It shows both battery state of charge when you turn on the ignition without starting and the alternator output when the engine is running.

for the moment yes because my obd gauge ( lufi xf revolution) is still on my old F20.

hmm upon starting the voltage was instantly 14+V . and state of charge says 60%. after driving for like 5km? it only went up by 1%!. weak battery then?

[Billfitz]

Not likely. BMW batteries routinely last seven to ten years. Mine is eight and is going strong. 5kM is not enough to charge a battery. That's the problem with city driving.

[Wellingtonz]

Originally Posted by Opie55

Actually, battery state of charge is not a parameter to add to the dashboard - it is on a separate screen where you register a new battery, so its' already there.

so upon starting the voltage was instantly 14+Volts and state of charge was 60%(keep in my I just got home like 5 hours ago) . after driving like 5km it only went up by 1%. is it a weak battery?

[Opie55]

If you go into the long list of 100 or so parameters you can monitor you will find at least 2 about voltage. One is "Battery Voltage" and one is "Battery Voltage at the IBS." You can select either one or both if you want. They will read nearly identically. The IBS is the Intelligent Battery Sensor. It's a tiny electronics box on your negative battery terminal clamp. An IBS is used in cars like ours with "smart" alternators. Bimmerlink is just telling you that the voltage is being measured at that spot. Once you add that parameter to your "dashboard" you are live monitoring how your alternator is charging the battery. Again, it should be 14.7 to 14.9 volts or thereabouts most of the time. I think you are too worried about an alternator problem just because the car said the battery was low. If the car was sitting at a used car lot I'd expect that. On the bimmerlink home screen there will be an icon just labelled "12v battery." Click on that and check the percentage charge. Drive the car a while and check it again (you have to click out and back in to read it again - it does not change live). Then check it again the next day before driving. So long as your percentage charge gets into the 80s, and it does not drop significantly overnight, you are good.

[Opie55]

Originally Posted by Wellingtonz

so upon starting the voltage was instantly 14+Volts and state of charge was 60%(keep in my I just got home like 5 hours ago) . after driving like 5km it only went up by 1%. is it a weak battery?

To soon to tell. 5km is nothing. Go drive 50km. And as I said above, if using Bimmerlink, you have to exit the percent charge and then re-click on it to get a new reading.

[Opie55]

Originally Posted by Billfitz

Are you going to drive around all the time with your Bimmerlink hooked up? The meter I linked is always on, out of the way on your console. It shows both battery state of charge when you turn on the ignition without starting and the alternator output when the engine is running.

Not sure why anybody would have bimmerlink on all the time. I just check the state of charge occasionally, more out of curiosity than anything just to see what is does after sitting a week or more.

[Billfitz]

No one should have Bimmerlink on all the time, just as no one should use it as a battery monitor. That's not what it's made for. Battery monitors are. The OP has an issue that requires using the right tool for the job. Bimmerlink isn't it. I didn't worry much about my battery until it turned seven years old, at which point I plugged my monitor in and left it in.

[HighlandPete]

Originally Posted by Wellingtonz

hmm upon starting the voltage was instantly 14+V . and state of charge says 60%. after driving for like 5km? it only went up by 1%!. weak battery then?

Not necessarily, once the SoC is at a certain percentage (possibly as low as 60%) the intelligent monitoring moves to an alternator support function and doesn't charge as a conventional system. Simply retains that SoC, unless you get 'energy harvesting' from lots of over-run situations.

If you do go for a drive, ensure you completely lift off the throttle when slowing down, to get maximum alternator charging. Charging voltage can increase in the over-run phase, will typically increase from ~14.4V to 14.7 - 14.8V.

[HighlandPete]

I've posted this comment before, hope it helps.

Charging AGM with IGR

My experience, simply driving to charge the battery doesn't necessarily work as we would like. I've checked the sleeping voltage of a partly discharged battery (~12.35V), before a trip of say 35 miles and then 24hrs later, it is no different.

Highway driving is the worse type of driving, as there are little over-run situations, when the alternator gives maximum charge. You need lots of over-run opportunities to 'up' the SoC, when the voltage is in the phase where the alternator only 'supports' the battery, not charge it. SoC has to drop to quite a low SoC threshold (BMW are not clear on this lower threshold, I suspect ~60% from some of the data), before we get the energy management to switch to a conventional charge regime. Once back above that threshold, energy management returns to the 'support' phase and we need the over-runs to continue to improve the SoC.

It goes against what we may be used to with 'simple' charging systems, where a steady run was best for charging a battery in the vehicle.

[Livetodrive]

I have a 2016 F30. It has the original battery. I suspect you just need to put the battery on a battery charger. If the issue goes away you can head towards Raffles and enjoy a drink.

[Wellingtonz]

Originally Posted by Billfitz

Not likely. BMW batteries routinely last seven to ten years. Mine is eight and is going strong. 5kM is not enough to charge a battery. That's the problem with city driving.

I checked the battery and it isn't a bmw branded one. forgot what it was. will check again

[Opie55]

Originally Posted by Wellingtonz

I checked the battery and it isn't a bmw branded one. forgot what it was. will check again

Does not matter if it's BMW-branded or not. What matters is (1) whether it is the correct size and type for the car, and (2) that it was registered to the car if it is not the original battery (which I guess it is not).

[Opie55]

Originally Posted by Billfitz

No one should have Bimmerlink on all the time, just as no one should use it as a battery monitor. That's not what it's made for. Battery monitors are. The OP has an issue that requires using the right tool for the job. Bimmerlink isn't it. I didn't worry much about my battery until it turned seven years old, at which point I plugged my monitor in and left it in.

Huh? Bimmerlink has hundreds of functions and monitoring battery voltage is one of them. I originally got it for the sole purpose of live monitoring the transmission fluid temp when changing the fluid. Is that not what it's for either?

[Opie55]

If you click the "12v Battery" icon on the Bimmerlink home screen, right below the percentage charge it will tell you the mileage at which the last battery was registered. What is that number compared to your current mileage? If it is blank, then your "new" non-BMW battery was never registered.

[Billfitz]

Originally Posted by Opie55

Huh? Bimmerlink has hundreds of functions and monitoring battery voltage is one of them.

Monitoring is something that's done constantly, not periodically.