[TurtleBoy]

Originally Posted by johndoe1983

Bmw has installed a 4 amp battery tender on my 440i.

They told me to disconnect the 48 volt terminal on the battery and let the charger do it’s job. The hood is not lock.

My car will be stop for 5 full months. Hope this will work.

What do you think?

Thanks

If you do that, make sure you follow the procedures in the SIB concerning long term storage. Have your dealer give you the SIB attachment so you can make sure your are disconnecting G14*1B.

https://static.nhtsa.gov/odi/tsbs/20...88948-9999.pdf

[Emily172013]

I just returned this afternoon from having my 2020 (11/2019 build) M340i serviced. The cars in the showroom had chargers on them with the hoods closed but not latched.
I have used a Battery Tender Plus for for many years on all my cars and motorcycles with all kinds of batteries. I have never had a problem bringing anything up to a full charge give or take 24hrs.

[nealjay]

had it at. 60 %
plugged in the charger in closed door Idrive and hood , finished charging after 24. hours green light and all check the battery level it was still at 60 did. nothing. so dunno whats wrong with this but ended up driving like 4 hours like a week later and it brought battery to 80. takin it to the dealer for a coolant temp sensor being off . I only got 2k miles on this check engine light too

[anandn]

My CtEK MXS 5 shows that my 12 volt battery is fully charged. Hood open. 440i convertible in storage for 4 weeks.

[bavarianride]

Originally Posted by anandn

My CtEK MXS 5 shows that my 12 volt battery is fully charged. Hood open. 440i convertible in storage for 4 weeks.

That is good data point showing that 5A also works.

Was your 440i's 12V battery relatively full when MXS 5 was plugged in?

[anandn]

Originally Posted by bavarianride

That is good data point showing that 5A also works.

Was your 440i's 12V battery relatively full when MXS 5 was plugged in?

Don’t know. Probably not. The car was sitting at the dealer for six weeks before I could fly down to Florida to pick it up. The charger was at stage 3 (bulk charging phase) for 12+ hours and then rapidly advanced to stage 7. Stage 7 to 8 took 2 weeks.

[johndoe1983]

Thanks Turtleboy, I will follow your advice.

One thing I do not understand. Why a 4.3 amp could not charge a 12 volt battery? My car is not eating 4 volt an hour in storage ?

I keep my 2 12 volt lead acid deep cycle battery charge all winter long with an 800 mili amp charger. Very weird this situation.

[TurtleBoy]

Originally Posted by johndoe1983

Thanks Turtleboy, I will follow your advice.

One thing I do not understand. Why a 4.3 amp could not charge a 12 volt battery? My car is not eating 4 volt an hour in storage ?

I keep my 2 12 volt lead acid deep cycle battery charge all winter long with an 800 mili amp charger. Very weird this situation.

Unfortunately Im not sure anyone can answer that, at least not that I have seen.

[johndoe1983]

Today I bought a 15 amp Nautilus AGM battery charger to deal with that problem. In less than an hour the battery was full, I unplugged the connector at the 48 volt battery and left the hood open till next may 2023. Praise the Lord.

**sorry I do not know how to turn the images on the right side.**

[Teutonic]

Originally Posted by wojtuswojtus

I picked up my new car a month ago and have had sme battery issues as others. Original BMW charger gets hot and it does not work. I took my car to the dealer and they tested extensively. Apparently the orginal BMW charger (4 AMP) is not powerful enough for my car. The mechanic said to buy a stronger AMP charger and I did. He said 15 AMP....

I bought 10 AMP Noco Genius charger and the car does not keep waking up when charging. The mechanic originally suggested 15 AMP or higher. Official BMW USA response was they did not have proper chargers and we should charge the batter directly at the trunk..... not sure about that. Anyhow, since I got my stronger charger, my car charges properly but this method was not official response from BMW USA. The original BMW charger (4 AMP) was getting very hot and car was constantly waking up. With the charger I have now (10 AMP), it does not do that anymore.
I hope BMW USA finds a proper charger for our cars. I even went into BWM Scottsdale parts dealer and they said they didnt have chargers for my car. They did confirm the 4 AMP BMW charger did not work.

I bought a Noco 5 and doesn't work on my 2021 340i.
I bought a Noco 10 and doesn't work on my 2021 M340i.

How the heck it works for you is mind-blowing for me. I still have grinding noises and electric motors noises.

I have three bimmers and only the M340 does that. My 2021 X4 is also Mild Hybrid Technology and works with both Noco 5 and Noco 10 with no issues.

Disconnecting the 48V plug should not be an offcial process for a normal user of the car. And I don't think it is. Even so, pulling that plug all the time it might get damaged at one point.

I am so sick of this that I was thinking of literally suing or forcing BMW to take the car back, but I don't have time for that now. They give you the car and screw it. It eats the battery like is no tomorrow and no charging protocol has officially been released. I wish I go back to my old cars that were left even 6 months without a charge and nothing happened. These new cars are just eating power non-stop and are a pain to deal with. Not to mention this MHT technology is all bullshit.

See my thread here.
https://f44.bimmerpost.com/forums/sh....php?t=1884955

[Teutonic]

Originally Posted by anandn

Don’t know. Probably not. The car was sitting at the dealer for six weeks before I could fly down to Florida to pick it up. The charger was at stage 3 (bulk charging phase) for 12+ hours and then rapidly advanced to stage 7. Stage 7 to 8 took 2 weeks.

Is yours a mild Hybrid Vehicle?
If yes, when charging, are any noises on the engine bay area? (electric motors noises and such?)

[anandn]

Originally Posted by Teutonic

Is yours a mild Hybrid Vehicle?
If yes, when charging, are any noises on the engine bay area? (electric motors noises and such?)

Yes it is, a 2023 440i convertible. I did hear odd noises in the engine bay when I plugged in the charger back in October but I don't know if it is still doing it. I've been away for 2 months and next week I will be back in FL where the car is stored. The charger still shows a fully-charged 12 v battery.

[anandn]

Originally Posted by Teutonic

Thank you for your reply. Very long charges with those mechanisms working around is a no-no for me.

With the way BMW has set up the 12v battery to be charged (hood open), the car is almost never in sleep mode. It seems to be always running something in the background. My CTEK MXS 5 has been in float mode most of time. According to CTEK, in float, the charger is providing a constant voltage charge to keep the battery maximally charged. In stage 8, which is pulse mode, the charger only sends a charge when the battery voltage drops below 95% due to self-discharge. My charger only went to pulse stage 8 once but then went back to stage 7.

I hooked up the charger to the terminals in the engine bay and closed the hood without latching it. I then selected AGM mode in the charger and plugged it into the wall. I then locked the doors but my BMW app says the car is unlocked. The charger was in stage 3, bulk charging phase, for about 16h. It got very warm in this stage and I was told by CTEK that is is normal. Once the charger got to stage 4, the charger rapidly advanced to stage 7.

STEP 7 FLOAT
Maintaining the battery voltage at maximum level by providing a constant voltage charge.
STEP 8 PULSE
Maintaining the battery at 95–100% capacity. The charger monitors the battery voltage and gives a pulse when necessary to keep the battery fully charged.

[Teutonic]

Originally Posted by anandn

Yes it is, a 2023 440i convertible. I did hear odd noises in the engine bay when I plugged in the charger back in October but I don't know if it is still doing it. I've been away for 2 months and next week I will be back in FL where the car is stored. The charger still shows a fully-charged 12 v battery.

Thank you for your reply. Very long charges with those mechanisms working around are something that worries me as this is not engineered that way, so is a no-no for me. Anyway, a 5 Ah charger should not take as long as you describe. A 10Ah usually takes 4-5 hours, and a 5Ah should be done in a max of 10 hours. I maintain my other two BMWs with Noco 5Ah and it takes 4-5 hours, sometimes less. Two weeks to keep the vehicle on a charge with those little motors whining around is not ok. But that's just my 2 cents

[Teutonic]

Originally Posted by anandn

With the way BMW has set up the 12v battery to be charged (hood open), the car is almost never in sleep mode. It seems to be always running something in the background. My CTEK MXS 5 has been in float mode most of time. According to CTEK, in float, the charger is providing a constant voltage charge to keep the battery maximally charged. In stage 8, which is pulse mode, the charger only sends a charge when the battery voltage drops below 95% due to self-discharge. My charger only went to pulse stage 8 once but then went back to stage 7.

I hooked up the charger to the terminals in the engine bay and closed the hood without latching it. I then selected AGM mode in the charger and plugged it into the wall. I then locked the doors but my BMW app says the car is unlocked. The charger was in stage 3, bulk charging phase, for about 16h. It got very warm in this stage and I was told by CTEK that is is normal. Once the charger got to stage 4, the charger rapidly advanced to stage 7.

STEP 7 FLOAT
Maintaining the battery voltage at maximum level by providing a constant voltage charge.
STEP 8 PULSE
Maintaining the battery at 95–100% capacity. The charger monitors the battery voltage and gives a pulse when necessary to keep the battery fully charged.

Either way, 2 weeks is enormous to reach that 95%! It should be done in a matter of hours with a 5Ah charger. Yes, maintenance is ok, and I know how it works. The initial charging is the problem. However, even so, some people can just charge it; not everyone has a garage or underground parking to keep a charger connected.
In my garage, I can do that too. I wonder what people without a garage do with these cars in Europe. Do they leave the hood open overnight or for two weeks? The next day your car is on the Police missing list.

The quietness that BMW keeps in this problem makes me mad. My both dealership do not know OFFICIALLY what to do. They show how nicely their 3000 dollars chargers work, and that's it! When I gave them my BMW original charger, My Noco 5 and my Noco 10 to use them they didn't know what to do. After trying my chargers on other new vehicles from their lot and having the same problem, they were baffled.
Thanks, BMW!

[anandn]

Originally Posted by Teutonic

Thank you for your reply. Very long charges with those mechanisms working around are something that worries me as this is not engineered that way, so is a no-no for me. Anyway, a 5 Ah charger should not take as long as you describe. A 10Ah usually takes 4-5 hours, and a 5Ah should be done in a max of 10 hours. I maintain my other two BMWs with Noco 5Ah and it takes 4-5 hours, sometimes less. Two weeks to keep the vehicle on a charge with those little motors whining around is not ok. But that's just my 2 cents

I agree that it should not take 16h. I use the same CTEK charger in my 2022 Volvo XC60 PHEV and the charger gets to stage 7 in a few hours. With the BMW, because the car is not in sleep mode and is pulling power from the 12v battery, the charger takes a long time.
One could always lock the car and not use a charger and maybe then the car will go to sleep. If it doesn't, not only will it drain the 12v battery but also the hybrid battery. Even if car does go into sleep mode, 12v AGM batteries will be completely drained in 2 months.
It just seems safer to me use a charger for the 12v battery which self-dicharges pretty quickly compared to the 48v Li ion battery.
Anyway, I will know in about 2 weeks if all is fine.

[anandn]

Originally Posted by Teutonic

Either way, 2 weeks is enormous to reach that 95%! It should be done in a matter of hours with a 5Ah charger. Yes, maintenance is ok, and I know how it works. The initial charging is the problem. However, even so, some people can just charge it; not everyone has a garage or underground parking to keep a charger connected.
In my garage, I can do that too. I wonder what people without a garage do with these cars in Europe. Do they leave the hood open overnight or for two weeks? The next day your car is on the Police missing list.

The quietness that BMW keeps in this problem makes me mad. My both dealership do not know OFFICIALLY what to do. They show how nicely their 3000 dollars chargers work, and that's it! When I gave them my BMW original charger, My Noco 5 and my Noco 10 to use them they didn't know what to do. After trying my chargers on other new vehicles from their lot and having the same problem, they were baffled.
Thanks, BMW!

You are welcome. The charger did not take 2 weeks to get to stage 7. It took about 24h. It was stage 3, bulk charging stage for 16 h and then rapidly went to stage 7. At stage 7, the charger is cool to the touch. I did not know of these intricacies of charging the 12v battery in a modern BMW. My previous fun car, a 2018 Porche 911, was very easy to set up with a CTEK charger.

[Teutonic]

Originally Posted by anandn

You are welcome. The charger did not take 2 weeks to get to stage 7. It took about 24h. It was stage 3, bulk charging stage for 16 h and then rapidly went to stage 7. At stage 7, the charger is cool to the touch. I did not know of these intricacies of charging the 12v battery in a modern BMW. My previous fun car, a 2018 Porche 911, was very easy to set up with a CTEK charger.

Believe me, me neither. This is the first BMW that I started to hate. All previous ones were fine and I still own a 2012 that can stay for months without trouble. The new ones are just a headache. I honestly looking to get rid of it and it doesn't even have 1000 km on board yet. I will see, but I have other things on my plate for now.

[bavarianride]

Originally Posted by Teutonic

Believe me, me neither. This is the first BMW that I started to hate. All previous ones were fine and I still own a 2012 that can stay for months without trouble. The new ones are just a headache. I honestly looking to get rid of it and it doesn't even have 1000 km on board yet. I will see, but I have other things on my plate for now.

One thing to try is to make sure ignition is off before charging, e.g. press start button to turn off engine, then open door. iDrive should be blank except for park icon.

[nealjay]

Originally Posted by Teutonic

Is yours a mild Hybrid Vehicle?
If yes, when charging, are any noises on the engine bay area? (electric motors noises and such?)

yea ticks and clinks like every minute or so dunno why got the. m440. 21 and went to stage 7. but never charged. battery. it stayed at same 65 % dunno what it is with this car and the charging

[JSaid]

Been having the same problems as everyone else with the ticks and clicking etc with ctek mxs5.

Just ordered NOCO Geniuspro25 off Amazon and gonna give it a try with 25 amps to see if it charges to full. Can use 5 amp mode for trickle charging too when the 48 volt is disconnected. 30% off for cyber Monday too

https://www.amazon.com/NOCO-GENIUSPR.../dp/B08Q2WD66S

[bavarianride]

Originally Posted by JSaid

30% off for cyber Monday too

https://www.amazon.com/NOCO-GENIUSPR.../dp/B08Q2WD66S

Wow these are high end chargers. It kind of sucks that MH 48V requires special handling ....