[TurtleBoy]

Originally Posted by Marty in NY

Then over time there were multiple batteries used depending on the year and options but at no time were there three batteries in the car at the same time. Is this what its boiling down to?

That is what it seems like. What we need is someone with the M60i and the Adaptive M Professional Suspension option to check and see how many batteries they have. Since that has now gone to the 48v MH the AGM under the hood may be also.

[MattAu]

Got my car back. I was told all is well. I have now plugged in the CTEK and it's been an hour and it's at Stage 4.

Does it make sense to use the eyelets and have them permanently mounted to the posts? This way, it's easier to plug and unplug the CTEK. Mind you since we have to open the hood anyway, maybe it makes less of a difference than if we can plug and unplug from the outside so to speak.
https://smartercharger.ca/products/c...31726989967463

BTW, what's under my hood looks same as what's under Marty's I don't see 12V batteries (Li-ion or AGM) near the Positive battery post. And the 48v battery is underneath/closer to the windshield - LG Chem 10Ah 440Wh 44V battery.

[TurtleBoy]

Originally Posted by MattAu

Got my car back. I was told all is well. I have now plugged in the CTEK and it's been an hour and it's at Stage 4.

Does it make sense to use the eyelets and have them permanently mounted to the posts? This way, it's easier to plug and unplug the CTEK. Mind you since we have to open the hood anyway, maybe it makes less of a difference than if we can plug and unplug from the outside so to speak.
https://smartercharger.ca/products/c...31726989967463

BTW, what's under my hood looks same as what's under Marty's I don't see 12V batteries (Li-ion or AGM) near the Positive battery post. And the 48v battery is underneath/closer to the windshield - LG Chem 10Ah 440Wh 44V battery.

That is good to hear, hopefully all goes well. I wouldn't use them but probably nothing wrong if you do, assuming the cap on the positive terminology will close with them on.

[jad03060]

It looks like three batteries in this diagram, but it's for the 50i, not 40i. https://www.realoem.com/bmw/enUS/sho...16#61128797706

[TurtleBoy]

Originally Posted by jad03060

It looks like three batteries in this diagram, but it's for the 50i, not 40i. https://www.realoem.com/bmw/enUS/sho...16#61128797706

According to the technical docs there are only two, hence the dual storage system. That diagram shows two different methods of wiring, note the end dates.

[MattAu]

Looks like I might be ok…. Checked this morning and CTEK was at Stage 7.

It’s so easy to plug and unplug at the posts and hopefully this is something I only need to do once a month, I’m not going to make things more complicated by attaching the eyelets.

Thank you both TurtleBoy and Marty in NY for your patience and responses.

[TurtleBoy]

Originally Posted by MattAu

Looks like I might be ok…. Checked this morning and CTEK was at Stage 7.

It’s so easy to plug and unplug at the posts and hopefully this is something I only need to do once a month, I’m not going to make things more complicated by attaching the eyelets.

Thank you both TurtleBoy and Marty in NY for your patience and responses.

Excellent. Good job and good luck in the future.

[Marty in NY]

Originally Posted by MattAu

Looks like I might be ok…. Checked this morning and CTEK was at Stage 7.

It’s so easy to plug and unplug at the posts and hopefully this is something I only need to do once a month, I’m not going to make things more complicated by attaching the eyelets.

Thank you both TurtleBoy and Marty in NY for your patience and responses.

I also learned via our discussion. So, what did the dealer say, was it your 12v AGM that was low or??

[MattAu]

Originally Posted by Marty in NY

I also learned via our discussion. So, what did the dealer say, was it your 12v AGM that was low or??

When I asked, I was told it's the battery in the front... so I assume that means the Li-ion 48v battery but that doesn't seem to make any sense based on our discussion so I assume he doesn't know what he's talking about.

Had he said it's the battery in the trunk, then at least it makes more sense.

[Marty in NY]

Originally Posted by MattAu

When I asked, I was told it's the battery in the front... so I assume that means the Li-ion 48v battery but that doesn't seem to make any sense based on our discussion so I assume he doesn't know what he's talking about.

Had he said it's the battery in the trunk, then at least it makes more sense.

Hmmm, well you said your car gave you a msg that said your Starter battery was severely drained, right? and we know the starter battery is the 12v one in the rear. We also know the 48v in the front gets charged by the 12v in the rear under normal conditions. It could get to be a vicious circle where they drain each other because one of them is bad or going bad or was just too far drained. Hard to know what the dealer meant, was it a sales or service person you talked with?

You said you picked up the car last week, right? I take this to mean you just bought the car and therefore it could have sat on the lot and little by little the battery drained cause they didn't have a charger on it.


In any event, if they did not replace either one and simply put a charger on the charge terminals in the engine bay, you better keep a close eye on the state of charge on your 12v starter battery. Providing you're driving the car on a regular basis, you should not need to put your CTEK on it for it to hold a proper charge but if it doesn't, then you'll be looking at a replacement in the near future.

[MattAu]

It was the sales person whom I spoke with, the Service Advisor was there as well but didn't say anything or disagree with the sales person.

I was told the car was delivered with over 80% SOC but that's because the car was plugged in while its PDI was being done. Which I guess was their way of saying it was fine when we delivered it and it's something I did that drained it - which I suppose is possible. It's a new car to us and I was definitely checking out the various settings and features and not always with the engine running.

I will definitely continue to monitor the car and the battery condition. In the meantime I have done two charging cycles with two different chargers (the CTEK MXS 5.0 and the BMW OEM one) and twice it went from stage 3 to Stage 7. And also, since I brought it in to the dealership, at least the issue has been "documented".

[jad03060]

BMW doesn't try to keep the 12vdc battery fully charged, although in some use cases, that can happen. That's one reason why they use an AGM battery which is longer lasting if it is discharged more than a regular lead-acid battery.

[swainbmw]

Originally Posted by MattAu

It was the sales person whom I spoke with, the Service Advisor was there as well but didn't say anything or disagree with the sales person.

I was told the car was delivered with over 80% SOC but that's because the car was plugged in while its PDI was being done. Which I guess was their way of saying it was fine when we delivered it and it's something I did that drained it - which I suppose is possible. It's a new car to us and I was definitely checking out the various settings and features and not always with the engine running.

I will definitely continue to monitor the car and the battery condition. In the meantime I have done two charging cycles with two different chargers (the CTEK MXS 5.0 and the BMW OEM one) and twice it went from stage 3 to Stage 7. And also, since I brought it in to the dealership, at least the issue has been "documented".

What setting are you using on the BMW charger? 🔌 Because there two different batteries types.

[jad03060]

Using the terminals under the hood, choose AGM.

[Gavroche]

I have 2023 model with mild hybrid system and CTEK 5.0 charger always got stuck at stage 3.

Then I use Schumacher SC1281. It is finally charged and is very quick. It is with 30A boost so I guess it also charges the 48v’s battery.

[TurtleBoy]

Originally Posted by Gavroche

I have 2023 model with mild hybrid system and CTEK 5.0 charger always got tuck at stage 3.

Then I use Schumacher SC1281. It is finally charged and is very quick. It is with 30A boost so I guess it also charges the 48v’s battery.

That is what I use and have been successful. I have only done the 30A boost once, other times just used the charge/maintain mode.

[GREENPUS]

Originally Posted by Marty in NY

Hmmm, well you said your car gave you a msg that said your Starter battery was severely drained, right? and we know the starter battery is the 12v one in the rear. .

I am always fascinated by what the 12/48 volt system does. On cold starts the 12 volt is the starter battery. When ICE is at or above 140F the 48 volt is the starter battery

[swainbmw]

[QUOTE=MattAu;30812502]It was the sales person whom I spoke with, the Service Advisor was there as well but didn't say anything or disagree with the sales person.

I was told the car was delivered with over 80% SOC but that's because the car was plugged in while its PDI was being done. Which I guess was their way of saying it was fine when we delivered it and it's something I did that drained it - which I suppose is possible. It's a new car to us and I was definitely checking out the various settings and features and not always with the engine running.

I will definitely continue to monitor the car and the battery condition. In the meantime I have done two charging cycles with two different chargers (the CTEK MXS 5.0 and the BMW OEM one) and twice it went from stage 3 to Stage 7. And also, since I brought it in to the dealership, at least the issue has been "documented".

I did the same I used the ctek and after about three days, it charged the battery took it off ordered the BMW charger and now the BMW charger won’t charge it at all. It just stays at level 3️⃣so I took it off Decided to let it sit for a week and I’ll try again

[Marty in NY]

[QUOTE=swainbmw;30932901]

Originally Posted by MattAu

It was the sales person whom I spoke with, the Service Advisor was there as well but didn't say anything or disagree with the sales person.

I was told the car was delivered with over 80% SOC but that's because the car was plugged in while its PDI was being done. Which I guess was their way of saying it was fine when we delivered it and it's something I did that drained it - which I suppose is possible. It's a new car to us and I was definitely checking out the various settings and features and not always with the engine running.

I will definitely continue to monitor the car and the battery condition. In the meantime I have done two charging cycles with two different chargers (the CTEK MXS 5.0 and the BMW OEM one) and twice it went from stage 3 to Stage 7. And also, since I brought it in to the dealership, at least the issue has been "documented".

I did the same I used the ctek and after about three days, it charged the battery took it off ordered the BMW charger and now the BMW charger won’t charge it at all. It just stays at level 3️⃣so I took it off Decided to let it sit for a week and I’ll try again

Have you pulled a Car Data Report and looked at the battery measurements in it? You can get it by logging into your MyBMW acct online and clicking on Car Data towards the top of the screen and then follow the prompts. Here are a couple sections about the battery.. .. it gives the report along with a pdf explaining all the categories, this pic is that pdf

[pshovest]

Originally Posted by GREENPUS

........On cold starts the 12 volt is the starter battery. When ICE is at or above 140F the 48 volt is the starter battery.......

My understanding is the 48v start is only used on restart after shutdown from ASS.

Are you saying that if I park, lock and then restart while engine temp is above 140F, the 48v system used?

[rmorin1249]

A bit off topic but related. I have a 2019 40i and also use a CTEK occasionally but my CTEK is an older model and instead of an AGM setting it has a snowflake symbol. A friend told me this is the same as the AGM setting and I should use it for maintaining AGM batteries. Is this correct? Thanks and pardon for going a bit off topic.

[Marty in NY]

Originally Posted by rmorin1249

A bit off topic but related. I have a 2019 40i and also use a CTEK occasionally but my CTEK is an older model and instead of an AGM setting it has a snowflake symbol. A friend told me this is the same as the AGM setting and I should use it for maintaining AGM batteries. Is this correct? Thanks and pardon for going a bit off topic.

According to the CTEK site, the snowflake is used for lead acid batteries without mention of AGM, here is their blurb.. .. and a link to their site.. .. https://www.ctek.com/uk/news-archive...me-winter-fun#