[gnx]

I checked the tech spec sheet to determine if the M2C battery is the 69AH lithium from the M4 or the same 80AH of the M2 but did not find any info.

Would like to know if the Lithium CTEK charger is the right one for the M2C.

Look at the price difference between the two batteries:

https://www.leebmann24.de/lithium-io...218047221.html

https://www.leebmann24.de/original-b...217555719.html

So if anyone finds out, please share.

[Inuyasha]

What is the weight difference, and if we use the M4 battery would it interfer with the warranty?

[Soren535]

WebETK does show different part numbers for batteries in the M2 and M2C but appears to be an AGM style battery again, just a bit bigger.

[hellrotm]

Originally Posted by Soren535

WebETK does show different part numbers for batteries in the M2 and M2C but appears to be an AGM style battery again, just a bit bigger.

Thats odd, I just checked ETK. It showed same battery for M2 and M2C. Part #: 61217555719

[hellrotm]

Some info from another thread. M2 at Goodwood had a lightweight battery.

Originally Posted by MR.

Hereby the photos of the lightweight battery...

MR

Originally Posted by hellrotm

Hmm, interesting. Most places in US list it as not for sale anymore.
61217635788 - 40AH - 11.8kg(26lbs)

M2 standard battery
61217555719 - 80AH - 23.6 kg(52lbs)

Anyone tried using the M4 lithium battery in the M2? Save 10kg(22lbs).
61218047221 - 69AH - 13.6kg(30lb)

[hellrotm]

Seen some Porsche owners buying this battery. Only 11.5 lbs, has a built in restart tech. Eliminates the worry of light weight battery leaving you stranded.

https://shop.antigravitybatteries.co...omotive/rs-30/

[Inuyasha]

Reads impressive. Hows the reviews? I think most people here dont want to void warranty so they’ll stick to BMW type battery.

[hellrotm]

Originally Posted by Inuyasha

Reads impressive. Hows the reviews? I think most people here dont want to void warranty so they’ll stick to BMW type battery.

Their was a group buy on rennlist. Seems to be getting great reviews. 45lbs light than the standard M2 battery.

[warrenw]

...why would a new battery void a warranty??

[scflaw]

do you still need to initialize the new battery to the car? its a total pain in the butt.

[MR.]

Originally Posted by warrenw

...why would a new battery void a warranty??

Hahaha if only you knew BMW is getting more anal in certain countries on any change you make.

I would not be amazed that within a few years time, you loose your warranty when you put a tennis ball on your tow hook as protection or hang an air refresher on your rear view mirror.

MR

[TR M2c]

I have a few questions
I hooked up my battery charger to the car but in what mode do i need to put it Normal of li ion ? And does anyone know of you van shut the hoofd when the charger is hooked up ? I am afraid to damage the jood with closing it?

[Abrunho]

Originally Posted by scflaw

do you still need to initialize the new battery to the car? its a total pain in the butt.

BimmerLink seems to include that function...

Originally Posted by TR M2c

I have a few questions
I hooked up my battery charger to the car but in what mode do i need to put it Normal of li ion ? And does anyone know of you van shut the hoofd when the charger is hooked up ? I am afraid to damage the jood with closing it?

I wouldn’t use a Lithium-Ion battery charger with the M2C original battery!
Something like the CTEK MXS 5.0 (selecting the AGM option) would be OK.

[norbtx]

Void your warranty because lithium batteries have different charge rates. That's why you need a dedicated lithium charger. Not worth it if you ask me.

[CSBM5]

Originally Posted by norbtx

Void your warranty because lithium batteries have different charge rates. That's why you need a dedicated lithium charger. Not worth it if you ask me.

The M2C does not have an Li battery. It's a standard AGM battery.

[Poochie]

In an already 3,500lbs vehicle, is the potential of losing 30 - 50lbs really worth the chance of getting stranded..

Hard pass for a daily driver..

Track or weekend car, maybe..

[norbtx]

Originally Posted by CSBM5

The M2C does not have an Li battery. It's a standard AGM battery.

Right, I meant I wouldn't get a lithium battery for cars that didn't have one from the factory, like those 911 owners.

[chris719]

I am not sure about the OEM lithium, but in general lithium ion chemistries tend to perform poorly at low temperatures. I would not want to be stranded in the name of saving 30 lbs that is already over the rear of the car.

Agree w Poochie

[F87source]

I don't think the CTEK is compatible with lithium ion batteries, just AGM, because litihum batteries run at lower voltages so the CTEK may over charge them. From what my SA told me the dealers use different chargers for the lithium batteries, so depending on what the M2C has use a respective charger for that battery.

[doug_999]

Originally Posted by Abrunho

I wouldn't use a Lithium-Ion battery charger with the M2C original battery!
Something like the CTEK MXS 5.0 (selecting the AGM option) would be OK.

Actually I just read that the snowflake mode is only for certain AGM battery manufacturers and I don't think the BMW is one of them.

[F87source]

Originally Posted by doug_999

Actually I just read that the snowflake mode is only for certain AGM battery manufacturers and I don't think the BMW is one of them.

Wait really? That's kind of weird and concerning, but I read through the ctek manual and there was no mention of that except snow flake mode was specifically for AGM batteries and cold conditions.


Also note:
You don't charge directly to the battery, you do it via the terminals under the hood otherwise you damage the IBS.

Snow flake mode pushes I believe 13.7V which should be fine with all AGM batteries. The IBS will stop any charging if it's too much and you'll get an error (if done so under hood), that's how you should know if it's over charging.

Plus BMW resells rebranded ctek chargers, and so do pretty much all major car brands. I've used a ctek multius 7002 for 2 years no on snowflake mode without any issues whatsoever.

[chris719]

Originally Posted by doug_999

Actually I just read that the snowflake mode is only for certain AGM battery manufacturers and I don't think the BMW is one of them.

All automotive AGM batteries are basically the same, and there are only a handful of manufacturers in the world. I think most BMW AGM batteries are mfg by Varta or Exide. Johnson Controls, Exide, and East Penn (Deka) make almost all the AGM batteries out there. There are some higher end batteries like Odyssey and Northstar which are a bit closer to a deep cycle design, but the fundamental chemistry is identical.