[bavarianride]

Originally Posted by Teutonic

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?”

FWIW, I think the issue is likely that the 48V system somehow wakes up/stays connected even when:
1. after the car is completely off(ignition off)
2. charged with jump terminals under the hood
3. hood stays open and up

If these conditions are met(per user manual), then foreman should ask field engineers to check your car to diagnose why 48V system wakes up.

[bimmer456]

Originally Posted by bavarianride

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.

It's like a Prius where it does regen through some sort of alternator or like the 330e which can charge while driving.

[bavarianride]

Originally Posted by bimmer456

It's like a Prius where it does regen through some sort of alternator or like the 330e which can charge while driving.

It appears those with MHT charging issues are not DD, but I would assume they also have garages to store their cars for extended period of time, and leaving the hood open and up(to disconnect 48V?) while charging 12V should not be an issue.

[bimmer456]

Originally Posted by bavarianride

It appears those with MHT charging issues are not DD, but I would assume they also have garages to store their cars for extended period of time, and leaving the hood open and up(to disconnect 48V?) while charging 12V should not be an issue.

Yeah a regular maintainer for the 12v should be fine but don't quote me you may have to drive it from time to time to avoid damaging the 48v battery. So a non mild hybrid m340 is better in that way though it's good to take any ICE for a drive periodically.

[Teutonic]

Originally Posted by bavarianride

It appears those with MHT charging issues are not DD, but I would assume they also have garages to store their cars for extended period of time, and leaving the hood open and up(to disconnect 48V?) while charging 12V should not be an issue.

So, if you do not have a garage or not drive it daily, do not buy a BMW. Correct?

[bavarianride]

Originally Posted by Teutonic

So, if you do not have a garage or not drive it daily, do not buy a BMW. Correct?

In the context of charging your MHT, one observation can be that your usage may not align with the design parameters of the manufacturer.

So one thing to consider is to figure out how to hit those parameters, e.g. u may be able to make the ECU think the hood is open and up.

[HighlandPete]

Originally Posted by zazzau

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.

From my reading, several things could be going on. I've not got a complete picture, as I can't find any documents which have a simple but complete description.

Clearly there is the instruction to have the hood open, (User Manual and BMW service documents), as that initially switches off the 48V electrical system. (Activated again either by a system request, or external 12V charging). There is reference in a different document to high voltage batteries (plug-in hybrid) that charger activation for the 12V battery must be within 3 minutes from opening the bonnet/hood.

To ensure that all 12V batteries can be charged, the charging procedure must be started via the jumpstart terminal points within 3 minutes after opening the bonnet.

I'm wondering, (can't find support for this), if this "timing" may be involved with the 48V MHT. Why some seem to be able to charge with the typical 5A intelligent charger, and some users don't have success.

Thinking about it, If BMW are following the same design logic for the MHT as charging the PHEV's 12V battery from a 12V charger, it could be the immediate (less than 3 minutes) charger activation, which initiates the correct system request.

We need someone to test the 'timing', see if this is a critical part of starting a successful charge.

[HighlandPete]

Originally Posted by Teutonic

So, if you do not have a garage or not drive it daily, do not buy a BMW. Correct?

"Driving profile" ... this is an old chestnut.

Simply put, with energy management as it is these days, driving profile does have a part in keeping our battery/batteries in a good state of charge.

If our profile is outside the ideal, we do need to maintain our batteries.

BMW's advice during Covid, gave a good clue to how we really need regular battery maintenance, if we don't use a vehicle regularly.

BMW UK posted the following...

Battery
If, as part of your essential-only travel during the coronavirus outbreak, your engine runs for approximately 20 minutes once a week, the battery in your car is unlikely to go flat.

Car batteries, like any battery, discharge when not used. Your car takes some power from the battery even when locked and parked, to power essentials such as the alarm.

How long you can leave your car without starting depends on the condition of your car's 12-volt battery. A BMW with a healthy battery should last at least 2 weeks, without needing to be started up to re-charge.

Try to minimise excessive 'wake ups' of your car’s electrical systems. Avoid locking/unlocking or switching on the ignition without driving the car where possible. Start the engine before listening to the radio or using your headlights, heating or air conditioning system.

If there’s any doubt about the condition of the battery, or the car will not be used for longer than three weeks, we suggest you connect it to a BMW Battery Charger or a suitable trickle charger. Please note the car’s warranty covers the battery for manufacturing defects but not for depletion as a result of lack of use.

[Teutonic]

Originally Posted by HighlandPete

"Driving profile" ... this is an old chestnut.

Simply put, with energy management as it is these days, driving profile does have a part in keeping our battery/batteries in a good state of charge.

If our profile is outside the ideal, we do need to maintain our batteries.

BMW's advice during Covid, gave a good clue to how we really need regular battery maintenance, if we don't use a vehicle regularly.

BMW UK posted the following...

Two weeks?
My Honda sitted for eight months with nobody being home to even touch it and started when I pulled the key out if my pocket. Tried to fill the battery thinking it was low and to my surprise the charging to full took little over one hour. Talking about a good car that really shuts off when you press LOCK. And that one was also fully loaded with alarm on.
So I disagree,something is too much and off with these cars, and the more I look into it, the more disgusted I get.
I own a 2012 BMW as well, the guy can sit few months without any trouble with the alarm on, and even that guy still works sometimes as you can hear buzzing once in a while. Yet, while not perfect, he is ok and never got me to “dangerously low battery level”.

Very dissapointed by the power consumption in these cars. I rather have none of the nanies that take so much power. I probably need to sell it and find myself something else, or an almost new preMHT era vehicle.

What bothers me the most is the fact that BMW comes with no official response or proper instructions. And to make it more confusing, some people can charge it with a 5 A and some don’t?!

In my opinion, nice car but shitty car. Not sure that I want that anymore. Even if I can deal with it, just the principle of it bothers me tremendously As I feel lied and ignored by the manufacturer.

If I knew about this ahead, I would have never buy it. In the end, it doesnt’t matter about the instructions an Covid crap, what it matters is the fact that BMW is incapable of making a car that shuts down everything when you press the lock button like others, keeping only the alarm in a stand-by mode.

[HighlandPete]

To be honest, it is what it is, has been so for at least 10-years.

Originally Posted by Teutonic

Two weeks?
My Honda sitted for eight months with nobody being home to even touch it and started when I pulled the key out if my pocket. Tried to fill the battery thinking it was low and to my surprise the charging to full took little over one hour. Talking about a good car that really shuts off when you press LOCK. And that one was also fully loaded with alarm on..

My F11 (2011) needs a maintenance charge, if not using it regularly. I attach a CTEK every couple of weeks to keep the battery topped up through winter.

Using it 3 times a week, about 25 miles each trip, just about holds the same charge, during the winter months. Anything less and the battery SoC will slowly drop off, as energy demand is higher than the driving charge available. It's not the battery, (same with it's new one) it is the nature of the beast.

The closed circuit current draw can be quite high, without a discharge warning. For vehicles like mine, the following applies.

Closed-circuit Current
Upwards of a closed-circuit current level of 80 mA, a Check Control message is generated (raised battery discharge rate when parked).

Each vehicle has a current draw, many something like 20 mA, without being abnormal. We see BMW give a good bit of headroom before a warning is generated.

I can see why BMW gives specific instructions to BMW dealers, why they need to regularly charge the batteries of vehicles stored on their sites.

[JSaid]

So the NOCO 25 got here and I gave it a shot. So first off, it works. After plugging it in, it began charging with no clicking noises! Only noticed one sound closer to full charge which I believe was a switch to charge the 48v. After the sound I noticed the battery level in idrive started going up.

One thing I did notice this time, if you plug the car in before all the interior lights go off, it starts clicking. If you wait ~5 minutes for everything to shut off and then begin charging, no clicking. This is different than what I experience with the mxs5, that one I couldn't get the clicking to stop no matter what

[bavarianride]

Originally Posted by JSaid

So the NOCO 25 got here and I gave it a shot. So first off, it works. After plugging it in, it began charging with no clicking noises! Only noticed one sound closer to full charge which I believe was a switch to charge the 48v. After the sound I noticed the battery level in idrive started going up.

One thing I did notice this time, if you plug the car in before all the interior lights go off, it starts clicking. If you wait ~5 minutes for everything to shut off and then begin charging, no clicking. This is different than what I experience with the mxs5, that one I couldn't get the clicking to stop no matter what

Can u retry with mxs5 after waiting ~5 minutes for everything to shut off? If that works then that would be the solution for many.

[bavarianride]

Originally Posted by HighlandPete

To be honest, it is what it is, has been so for at least 10-years.

Correct, my 2013 328i required a charge if not driven much.

[HighlandPete]

Originally Posted by JSaid

One thing I did notice this time, if you plug the car in before all the interior lights go off, it starts clicking. If you wait ~5 minutes for everything to shut off and then begin charging, no clicking. This is different than what I experience with the mxs5, that one I couldn't get the clicking to stop no matter what

Interesting, possibly fits with the "system request" comment and waking up the 48V battery. Could all be about charging start-up sequence. If it is, BMW could explain it a lot better.

[JSaid]

Originally Posted by bavarianride

Can u retry with mxs5 after waiting ~5 minutes for everything to shut off? If that works then that would be the solution for many.

So I did try that before ordering the Noco and unfortunately no luck . Seemed good for about 45 min then the clicking started up and progressively got more prominent. I originally thought that the battery management error only came on from disconnecting at the wrong time but it showed up after long enough on the mxs5. I'll try again with the mxs5 a little later to confirm

[Teutonic]

Originally Posted by JSaid

So the NOCO 25 got here and I gave it a shot. So first off, it works. After plugging it in, it began charging with no clicking noises! Only noticed one sound closer to full charge which I believe was a switch to charge the 48v. After the sound I noticed the battery level in idrive started going up.

One thing I did notice this time, if you plug the car in before all the interior lights go off, it starts clicking. If you wait ~5 minutes for everything to shut off and then begin charging, no clicking. This is different than what I experience with the mxs5, that one I couldn't get the clicking to stop no matter what

Thank you for the update!
A Few questions please:

1. So, when you plug it in without properly turned off, you still have the clicking? And is repetitive like with our regular chargers , or only once?

2. You managed to -somehow- be in the area when that click happened and presume that it switched to the lithium battery charge?
Or you slept beside it just to obseve? Very important…

3. Should I understand that once the 12 battery is charged, the system will switch to charging the 48V Li battery? And you can also visualize that on the screen?

4. If tht Noco was -obviously- set for AGM battery and 12 V,
- how it charges a 48V battery?
- and how does it given the AGM SETTING?
(i presume that the 12V system will automatically do that as they reciprocally charge one another?)


5. Did you try to put the 5 amp after everyting was charged just to confirm the theory that under a certain, minimal, voltage loss, the 5 Ah still works , and only under o bigger loss it doesn’t?

6. Can you put the charger on but lock the car in the meantime? Leaving the hood open of course. For ex, on the other BMWs I can.

Thats enough for today…
Thanks

[anandn]

My 2023 440i was in storage for 2 months in FL hooked to a CTEK MXS 5 amp charger. The charger has been at stage 7 for two months, green light indicating a fully charged battery. I left the hood unlatched as recommended by BMW.Today I started the car and there were two errors, battery maintenance and emergency call unavailable. Upon starting the car, the battery error disappeared but the emergency call unavailable is still there. Probably unrelated to the battery. So as far as I am concerned, all the clicks and whirring sounds that I ignored have not appeared to cause any issues. I will be driving the car in FL over the next 5 months and see if anything untoward crops up.

[TurtleBoy]

Originally Posted by anandn

My 2023 440i was in storage for 2 months in FL hooked to a CTEK MXS 5 amp charger. The charger has been at stage 7 for two months, green light indicating a fully charged battery. I left the hood unlatched as recommended by BMW.Today I started the car and there were two errors, battery maintenance and emergency call unavailable. Upon starting the car, the battery error disappeared but the emergency call unavailable is still there. Probably unrelated to the battery. So as far as I am concerned, all the clicks and whirring sounds that I ignored have not appeared to cause any issues. I will be driving the car in FL over the next 5 months and see if anything untoward crops up.

Did you check to see if you have any other connections (navigation lookup, concierge, etc.)? Your TCU may have went. Might want to try restarting iDrive and see if it comes. Could also try a Telematics restart although not convinced that is actually a thing but rather holding the button in for 70 seconds to make sure an iDrive restart is done.

[anandn]

Originally Posted by TurtleBoy

Did you check to see if you have any other connections (navigation lookup, concierge, etc.)? Your TCU may have went. Might want to try restarting iDrive and see if it comes. Could also try a Telematics restart although not convinced that is actually a thing but rather holding the button in for 70 seconds to make sure an iDrive restart is done.

My saved profile was unchanged. All settings were unchanged. I use CarPlay and all seems fine.

[TurtleBoy]

Originally Posted by anandn

My saved profile was unchanged. All settings were unchanged. I use CarPlay and all seems fine.

CarPlay uses your phone's connection and not the vehicle's. Wuite a few folks who had had the Emergency Call Malfunction message have had to get the TCU replaced so was wondering if you had any other symptoms, ie. the vehicle doesn't connect using its cell.

[anandn]

Originally Posted by TurtleBoy

CarPlay uses your phone's connection and not the vehicle's. Wuite a few folks who had had the Emergency Call Malfunction message have had to get the TCU replaced so was wondering if you had any other symptoms, ie. the vehicle doesn't connect using its cell.

My phone is connecting fine. All my settings are unchanged. I’ve only driven the car a few times since I took delivery in early October. Don’t know about anything else.

[TurtleBoy]

Originally Posted by anandn

My phone is connecting fine. All my settings are unchanged. I’ve only driven the car a few times since I took delivery in early October. Don’t know about anything else.

You are misunderstanding what I'm asking, your phone has nothing to do with it. The vehicle has a cell connection that is used for the emergency calling, real-time traffic, searching within navigation, calling concierge, etc. If the are not available then a bad TCU could be one of the reasons. Could also be that BMW servers are having an issue or the cell connection is down. Try restarting iDrive (push and hold in the volume button for 30 seconds. It is easiest to do while driving since you will get the feedback of the CID going black to signify the reboot has started) and see if the message goes away. If it continues then you will want to take it in to get looked at. Good luck and let us know how it turns out.