[zazzau]

Originally Posted by Teutonic

Your link is a little bit confusing as the guy "was told " that hood latched willcharge the 12 V battery.

What is confusing about it? With the latch open, it charges the 12v battery and the Li-ion. The latch controls whether or not the Li-ion is charged. My charger does not have an AGM mode so closing the hood to charge just the AGM makes sense. I have never done this. I usually close the hood but I don't latch it. But the next time I top off I will latch the hood.

Stupid question: If you're having battery issues why can't you take your car to the dealership?

[bavarianride]

Originally Posted by Teutonic

Go ti the trunk, reach the battery, disconnect one of the cables, put it aside to make sure there is no touch. Connect the charger to the battery poles and charge it that way. 3-4 hours should suffice to top it off; eventually leave it overnight as it goes in maintenance anyway.
Disconnect charger, connect cable back and you are good to go. I am doing it for a year now as I am not home and all my cars are sitting…

I can see this as PITA as there is no easy access to the AGM battery.

At least the F30 AGM battery is to the right of the trunk behind an easily-removable storage bin.

Also charging directly from the battery terminals may bypass certain built-in surge protection available through the jump terminals.

[zazzau]

Originally Posted by TurtleBoy

You never want to do that since you are bypassing the IBS. You could end up shortening your battery life as well as having problems with electronics.

Agreed. I don't think others should be encouraged to do this.

[bavarianride]

Originally Posted by zazzau

What is confusing about it? With the latch open, it charges the 12v battery and the Li-ion. The latch controls whether or not the Li-ion is charged. My charger does not have an AGM mode so closing the hood to charge just the AGM makes sense.

Stupid question: If you're having battery issues why can't you take your car to the dealership?

I think Teutonic's previous posts said service didn't have issue using shop charger on his MHT, but had the same issues with his own 5A chargers.

[zazzau]

Originally Posted by bavarianride

I think Teutonic's previous posts said service didn't have issue using shop charger on his MHT, but had the same issues with his own 5A chargers.

My understand is that the poster's car doesn't hold a charge and needs to be charged directly from the trunk.

I have gone as long as 2 months at a time with my car parked and locked. Never needed to charge it. So it's a question of why the poster thinks it's ok to keep getting in the trunk to charge the battery. Seems unnecessary if you ask me.

Perhaps the battery ought to be disconnected if gone for an extended period of time. Dunno. The longest I've gone is 3 months and I had no problems.

[Teutonic]

Originally Posted by TurtleBoy

You never want to do that since you are bypassing the IBS. You could end up shortening your battery life as well as having problems with electronics.

No, it doesn’t, you don’tt charge it with both cables connected as the manual says. Either so, some dealers suggested that you could charged via trunk as is! And that is probably a No No, yet, (read the thread) some dealers suggested it as via BMW channel.

[Teutonic]

Originally Posted by zazzau

What is confusing about it? With the latch open, it charges the 12v battery and the Li-ion. The latch controls whether or not the Li-ion is charged. My charger does not have an AGM mode so closing the hood to charge just the AGM makes sense. I have never done this. I usually close the hood but I don't latch it. But the next time I top off I will latch the hood.

Stupid question: If you're having battery issues why can't you take your car to the dealership?

I don’t have battery issues. WE have battery issues. Not specific to my personal vehicle per-se.
Read here
https://g20.bimmerpost.com/forums/sh....php?t=1884955

[TurtleBoy]

Originally Posted by Teutonic

No, it doesn’t, you don’tt charge it with both cables connected as the manual says. Either so, some dealers suggested that you could charged via trunk as is!

It definitely does that is why they say the battery should not be removed from the vehicle to charge it. The IBS will think it is at a lower state of charge and you may also get check control messages.

You do what you want, but it definitely is not recommended.

[Teutonic]

Originally Posted by zazzau

My understand is that the poster's car doesn't hold a charge and needs to be charged directly from the trunk.

I have gone as long as 2 months at a time with my car parked and locked. Never needed to charge it. So it's a question of why the poster thinks it's ok to keep getting in the trunk to charge the battery. Seems unnecessary if you ask me.

Perhaps the battery ought to be disconnected if gone for an extended period of time. Dunno. The longest I've gone is 3 months and I had no problems.

No, my cars keeps a charge but I am out of the country for long time. The alarm, camera and other gizmos are sucking the power continuously from the battery and that needs to be charged every three months or so, otherwise your screen will show lots of messages. The cars are not driven almost at all for now. I have two 2021 with under 1000 km on board. However, I had Honda that stayed 8 months without being touched and battery was almost full.
My 20212 BMW doesnt need anything like it. If I give him the original trickle charger for 3 hours after 5 -6 months he is getting full.

I cannot disconnect the battery, otherwise I cannot lock the car in the common parking ground where it sits now (!)

[Teutonic]

Originally Posted by TurtleBoy

It definitely does that is why they say the battery should not be removed from the vehicle to charge it. The IBS will think it is at a lower state of charge and you may also get check control messages.

You do what you want, but it definitely is not recommended.

No other choice mate. Or in three months when I get home I can not unlcok the car and need to buy a new battery.
I already bought two batteries on my 2021 X4. So screw this.

Of course you can remove the battery. How do you think they change the battery?
I just wish I can buy a regular bimmer with no BS battery or shitty MHT crap.

[TurtleBoy]

Originally Posted by Teutonic

Of course you can remove the battery. What crap is that?
I just wish I can buy a regular bimmer with no BS battery or shitty MHT crap.

I have never seen anything saying it is fine to remove the battery and charge it off-line only articles saying you shouldn't. Makes sense since it will cause the same IBS problems.

For example: "If your BMW is equipped with a lead-acid or AGM battery in combination with an intelligent battery sensor (IBS), you must connect the trickle charger at the jump-start terminal points in the engine bay. This way the IBS will recognize the charging. If you charge the battery directly at battery terminals or removed it from the car, this could lead to misinterpretation of the battery condition or unwanted check control messages and fault memory entries. "

https://bimmerist.com/how-to-charge-...ry-full-guide/

Good luck with yours.

[Teutonic]

Originally Posted by bavarianride

I think Teutonic's previous posts said service didn't have issue using shop charger on his MHT, but had the same issues with his own 5A chargers.

Please read my thread here. Is very detailed

https://g20.bimmerpost.com/forums/sh....php?t=1884955

The shop uses specific smart chargers made for BMw to address all models and batteries. We are not at that level.

Only the M340i MHT has troibles being charged with the 5 Ah or 10 Ah either Ctek, Noco or BMW chargers. All behave the same with this car but all work with the rest of the cars including my older BMW or my two Audis.

[Teutonic]

Originally Posted by TurtleBoy

I have never seen anything saying it is fine to remove the battery and charge it off-line only articles saying you shouldn't. Makes sense since it will cause the same IBS problems.

For example: "If your BMW is equipped with a lead-acid or AGM battery in combination with an intelligent battery sensor (IBS), you must connect the trickle charger at the jump-start terminal points in the engine bay. This way the IBS will recognize the charging. If you charge the battery directly at battery terminals or removed it from the car, this could lead to misinterpretation of the battery condition or unwanted check control messages and fault memory entries. "

https://bimmerist.com/how-to-charge-...ry-full-guide/

Good luck with yours.

I agree with you. If it works.
Are you charging yours? If yes, how and with what charger?
Because the IBS doesnt recognize the chargers.
Both dealerships do not know how to address the problem. BMW is quiet. MY machanic did not find the response from them. Again, read my thread

Your article does not refer to MHT vehicles and suggested a CTEK Mus 4 which is a 4 AH charger, which is perfect fro any battery on these vehicles. But I do have the CTEK 5 and it doesnt work either. So your article is futile for uour case.

When you will be in the position to put it in storage like me and can not charge it properly, you will understand.
This car does not accept chargers that provide the suggested Ah for this battery.
5-10 Ah battery chargers are perfect for any 80-200 battery.

[TurtleBoy]

Originally Posted by Teutonic

I agree with you. If it works.
Are you charging yours? If yes, how and with what charger?
Because the IBS doesnt recognize the chargers.
Both dealerships do not know how to address the problem. BMW is quiet. MY machanic did not find the response from them. Again, read my thread

Your article does not refer to MHT vehicles and suggested a CTEK Mus 4 which is a 4 AH charger, which is perfect fro any battery on these vehicles. But I do have the CTEK 5 and it doesnt work either. So your article is futile for uour case.

When you will be in the position to put it in storage like me and can not charge it properly, you will understand.
This car does not accept chargers that provide the suggested Ah for this battery.
5-10 Ah battery chargers are perfect for any 80-200 battery.

I understand you are between a rock and a hard place. I only tried a couple of times to charge it to see how it would go, neither was successful.

[zazzau]

Originally Posted by Teutonic

Anyway, 25 Ah is still aggressive for the battery and shortens the lifespam. Kept my bimmers for decades with 5 Ah chargers with zero problems and 8 plus years on battery life.

Well I can understand your concern. The CTEK I use pushes max current at Bulk charging. In my case that takes just a few minutes before it moves to Absorption stage — where "the current is gradually reduced" (to quote their technical doc.) This is where my charge spends the most time (few hours) before it gets fully charged.

This is probably how it works with dealer charger. You can perhaps contact CTEK for more tech details. The 25A rating just means it's the max it *can* push; it doesn't necessarily mean it's pushing at a constant 25A. Based on everything I've read it adjusts itself to what it believes the battery/system needs. You can of course contact CTEK. I don't have a battery analyzer to ascertain exact values while charging but it should be less than 25A going by CTEK.

Hope this helps.

[Teutonic]

Originally Posted by zazzau

Well I can understand your concern. The CTEK I use pushes max current at Bulk charging. In my case that takes just a few minutes before it moves to Absorption stage — where "the current is gradually reduced" (quoting technical doc.) This is where my charge spends the most time (few hours) before it gets fully charged.

This is probably how it works with dealer charger. You can perhaps contact CTEK for more tech details. The 25A rating just means it's the max it *can* push doesn't necessarily mean it's pushing at a constant 25A. Based on everything I've read it adjusts itself to what it believes the battery/system needs. You can of course contact CTEK. Hope this helps.

Deutronic chargers that BMW is using in the shops are professional grade units that can not be compared to what we use. Have a look at their settings. Don’t forget,those are shops chargers and are made tohelp the tech while working inclusding providing current for analyzing, repairs and other things without affecting your battery. Their inner software is not in your “regular Joe” unit.
Not lastly, that is a shop where they care about speed and time spent not your ideal charging pattern.

I guess that the fact that your battery gets charged in one hour instead of 4-5 (that a proper calculated charger) will provide the answer for you. Don’t forget that all these 4-5-6 Ah chargers are made like that for a scope.

By the rules, battery charging current should be 10% of the Ah rating of the battery.
Charging current for 100Ah Battery = 100 Ah x (10 ÷ 100) = 10Ah
That is the ideal Ah for charging such battery.

Why do you think BMW sells CTEK rebadged chargers that do not pass the limit?

[zazzau]

Originally Posted by Teutonic

I guess that the fact that your battery gets charged in one hour instead of 4-5 that a proper calculated charger willprovide the answer for you. Don't forget that all these 4-5-6 Ah chargers are made like that for a scope.

I didn't state that my battery charges in an hour. It takes several hours. I've left it plugged in for 10 hours in the past.

I'm by no means an expert; I'm just sharing my personal experience and what CTEK claims for that particular charger. But I can bet my money that it doesn't push 25A. If I'm able to get my hands on an analyzer I will be able to verify because I'm interested now that you mention it.

[Teutonic]

Posted wrong, Iguess.
Anyway, regardless of our conversation, my question is “why this vehicle does not accept the 5-10 Ah chargers like other vehicles do? Including 5 or even 7 series that have way bigger batteries?”
That is what I care.
I can buy a Noco 25 regardless of price. But the principle of the problem bothers me.
Not to mention, all those 25 Ah chargers are huge and not practical.

[zazzau]

Originally Posted by Teutonic

Posted wrong, Iguess.
Anyway, regardless of our conversation, my question is "why this vehicle does not accept the 5-10 Ah chargers like other vehicles do? Including 5 or even 7 series that have way bigger batteries?"
That is what I care.
I can buy a Noco 25 regardless of price. But the principle of the problem bothers me.
Not to mention, all those 25 Ah chargers are huge and not practical.

I don't think anyone can answer that. Some owners on this forum have reported success with the 5A. Why it doesn't work for others is a mystery. In fact I originally bought the CTEK 5 but after reading all the various threads I returned it. Never tried it. So not sure if I might have been lucky to get it to work like others. I ordered the 25 instead.

[anandn]

Originally Posted by zazzau

Read the fist post in the link below — I shared it earlier. It will answer your question:

48V Mild Hybrid Electronics https://g07.bimmerpost.com/forums/sh....php?t=1781421

I read that. Thanks

[bimmer456]

I think the engine charges the 48 volt system. It's not a plug in hybrid like the 330e where you can charge it with home charging.

[bavarianride]

Originally Posted by bimmer456

I think the engine charges the 48 volt system. It's not a plug in hybrid like the 330e where you can charge it with home charging.

Yeah I read some posts that 48V battery is charged by 12V battery while the car is in motion, and my guess is that the instruction to open the hood is to disconnect 48V battery from 12V battery. I can't find definitive reference from BMW though.