[nm146332]

Can anyone (UK-based ideally) recommend a good trickle charge for the X3 M40i? I don't do that many miles in it and it's been on my mind for a while and now seen a low battery warning. Stop/start doesn't kick in which is indicative of a low'ish battery.

Now for the silly question too....guessing there's a battery in the back somewhere for infotainment and other bits, does that need charging separately?

Cheers,
N

[Dandle]

I use a Ctek 7AH charger twice a year on my car, its suitable to be left on trickle charging the car all the time. Ctek are the supplier for lots of car manufacturers own chargers.

[Rottweiler]

CTEK - 40-206 MXS 5.0 Fully Automatic 4.3 amp Battery Charger and Maintainer 12V https://www.amazon.com/dp/B00CD44RQO..._yEEFs25uNTCIb

[R BMW]

Originally Posted by Rottweiler

CTEK - 40-206 MXS 5.0 Fully Automatic 4.3 amp Battery Charger and Maintainer 12V https://www.amazon.com/dp/B00CD44RQO..._yEEFs25uNTCIb

[nm146332]

That's really helpful - thanks very much!

[Rottweiler]

You can spend more and get higher amperage but I’m fine with this one

Main thing is to get a CTEK

Remember that your car has an AGM battery when you set the mode (it should have anyway) and don’t be a dumbass like I was and connect to the battery terminals themselves. Use the positive and ground posts under the hood

[nm146332]

Originally Posted by Rottweiler

You can spend more and get higher amperage but I’m fine with this one

Main thing is to get a CTEK

Remember that your car has an AGM battery when you set the mode (it should have anyway) and don’t be a dumbass like I was and connect to the battery terminals themselves. Use the positive and ground posts under the hood

Haha.... it's a good shout and the sort of thing I'd risk doing.

[turbobeagle]

If you have a mild hybrid model, using a charger can be a can of worms. There are a number of threads about this, and not just in the G01 forum. I personally had success with a 5 amp CTEK, but others ran into issues where the charge cycle would not complete. It also makes noises frequently while charging, which some have claimed is ok, but others say might be an issue. It will also throw a warning into iDrive about accessories not being turned off, which again, is likely ok to disregard but who knows for sure.

[dmicah]

Originally Posted by turbobeagle

If you have a mild hybrid model, using a charger can be a can of worms. There are a number of threads about this, and not just in the G01 forum. I personally had success with a 5 amp CTEK, but others ran into issues where the charge cycle would not complete. It also makes noises frequently while charging, which some have claimed is ok, but others say might be an issue. It will also throw a warning into iDrive about accessories not being turned off, which again, is likely ok to disregard but who knows for sure.

Pretty sure Rottweiler has an LCI/mild hybrid

[turbobeagle]

Originally Posted by dmicah

Pretty sure Rottweiler has an LCI/mild hybrid

??? I never said otherwise.

[dmicah]

Originally Posted by turbobeagle

??? I never said otherwise.

Sorry: guess I was thinking he was using the CTEK and it worked with his mild hybrid. But I guess you're saying sometimes it does (as for you and he) but sometimes it doesn't.

[Rottweiler]

Originally Posted by dmicah

Pretty sure Rottweiler has an LCI/mild hybrid

Yep…2023 X4

Haven’t noticed anything amiss, and I use the CTEK regularly as I don’t drive the car far (island life) or often (retired life)

It’ll light up 7 of the 8 indicators I believe, with the last one maybe being a different color?

I don’t think I’ve ever gone 8 for 8 though; was always curious re that

Fwiw as well; I coded start/stop off as soon as I got the car. I’m not a believer in it’s benefit long term, and fuel consumption is a non issue

[turbobeagle]

Originally Posted by dmicah

Sorry: guess I was thinking he was using the CTEK and it worked with his mild hybrid. But I guess you're saying sometimes it does (as for you and he) but sometimes it doesn't.

No apologies necessary, I was just confused by what you meant.

FWIW here is some info BMW had to put out regarding the use of 12V chargers on mild hybrids including the G01 (see the attached pdf in that link). TLDR: do it with the hood open, unless you disconnect the 48v system. Screwing it up can actually damage the 48v battery.

You can also see what some folks have been dealing with in that long thread.

[dmicah]

Cool! When I'm trickle charging I've got no problem leaving the hood open.

[g11hoonigan]

Been charging my G12 with hood open twice a month with ctek and have been doing the same since I got the G01 last year. No issues so far.

[Rottweiler]

I need to find my manual to see what that 8th light signifies

[g11hoonigan]

Originally Posted by Rottweiler

I need to find my manual to see what that 8th light signifies

Pulse


ÉTAPE 8 PULSE
Maintient la batterie à 95-100 % de sa capacité. Le chargeur surveille la tension de la batterie et envoie au besoin une impulsion por maintenir la batterie complètement chargée.

[Rottweiler]

Originally Posted by g11hoonigan

Pulse

So why do you think mine has never activated no matter how long it’s on the car?

I’m almost certain I get to 7 fairly quickly, which is maybe greenish

Never get to 8

🤔

[turbobeagle]

Originally Posted by Rottweiler

So why do you think mine has never activated no matter how long it’s on the car?

I’m almost certain I get to 7 fairly quickly, which is maybe greenish

Never get to 8

🤔

I believe you would have to wait for battery voltage to drop, which could mean a pretty long duration on the charger. And after pulsing, it would come back to 7 so you may not observe the 8th light without a camera monitoring it.

[Rottweiler]

Originally Posted by turbobeagle

I believe you would have to wait for battery voltage to drop, which could mean a pretty long duration on the charger. And after pulsing, it would come back to 7 so you may not observe the 8th light without a camera monitoring it

That’s helpful…thank you

[MontyB1]

There is a good thread on the right charger that works in the UK 3 series forum, it seems some charger don't charge the MHT which 'can' under some conditions be a concern. Worth a look over there.

[lfdal54]

Originally Posted by turbobeagle

No apologies necessary, I was just confused by what you meant.

FWIW here is some info BMW had to put out regarding the use of 12V chargers on mild hybrids including the G01 (see the attached pdf in that link). TLDR: do it with the hood open, unless you disconnect the 48v system. Screwing it up can actually damage the 48v battery.

You can also see what some folks have been dealing with in that long thread.

Thanks, that's a good read. When I connected my 4-amp BMW charger, BTW - it's a 5-year-old one, I got zero increase in charge on the 48v battery after 24 hours. This was per the cell "blocks" that show up on iDrive. Although reading that PDF BMW considers anything under 20-amp a trickle charger. The 12v battery moved from orange to green after about 6 hours.