Question: Charging the Battery

[Dannyvandelft]

According to the manual you should not hook it up directly to the battery. Use the terminals under the hood.

I read that. But it refers more to charging/jumping a low/dead battery.
The positive terminal in the trunk has a dedicated stud to hook up accessories like a tender. And another perk is you don't have wires dangling from the quick disconnect under the hood while driving. It's a really nice clean install in the trunk and when winter is over the quick disconnect easily stores in the battery compartment making it invisible till winter comes around again.

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[Axix23]

 

[Bundy]

I read that. But it refers more to charging/jumping a low/dead battery.
The positive terminal in the trunk has a dedicated stud to hook up accessories like a tender. And another perk is you don't have wires dangling from the quick disconnect under the hood while driving. It's a really nice clean install in the trunk and when winter is over the quick disconnect easily stores in the battery compartment making it invisible till winter comes around again.

Sure you don't want cables dangling under the hood if you intend to have it there while driving.
However it has been well documented in different BMW forums that it has its risk hooking up a charger directly to the battery. You could blow out the junction box and that will cost you +1000 dollar to fix. The charge needs to go through the IBS.

 

[Dannyvandelft]

Sure you don't want cables dangling under the hood if you intend to have it there while driving.
However it has been well documented in different BMW forums that it has its risk hooking up a charger directly to the battery. You could blow out the junction box and that will cost you +1000 dollar to fix. The charge needs to go through the IBS.

Yeah I read a bunch of posts on several BMW forums before I hooked it up. Some say you can't, others say it's fine. I haven't found anything official from BMW that say you can't, or shouldn't. So I'm assuming it's fine.

Edit: read a few more BMW forums, it said it's fine to charge from the trunk as long as the negative is connected to a chassis bolt (which mine is) so the IBS gets the right readings.

 

[Bundy]

Yeah I read a bunch of posts on several BMW forums before I hooked it up. Some say you can't, others say it's fine. I haven't found anything official from BMW that say you can't, or shouldn't. So I'm assuming it's fine.

Edit: read a few more BMW forums, it said it's fine to charge from the trunk as long as the negative is connected to a chassis bolt (which mine is) so the IBS gets the right readings.

For me it is a case of rather safe than sorry.
I know a lot of people are charging at the battery with no issues, but I am going to trust the people who developed the car and wrote the manual.
If they state to only use the terminals under the hood there is probably a good reason for it.
Obviously the car is not going to burst into flame and explode the second you hook up a charger to the battery but this is probably more a case of what is best for the battery/electronics long term.
If you are happy using your solution that is of cause what you should do.
I just stated what the manual said if someone who wants to do things according to the book read this thread.

 

[Retrocade]

For me it is a case of rather safe than sorry.
I know a lot of people are charging at the battery with no issues, but I am going to trust the people who developed the car and wrote the manual.
If they state to only use the terminals under the hood there is probably a good reason for it.
Obviously the car is not going to burst into flame and explode the second you hook up a charger to the battery but this is probably more a case of what is best for the battery/electronics long term.
If you are happy using your solution that is of cause what you should do.
I just stated what the manual said if someone who wants to do things according to the book read this thread.

This for me too. I mean the manual plainly says do not charge or hook up anything directly to the battery. IM sure its for a reason.

By the way anyone know how much one of these batteries cost? Little hard finding prices on these cause so new. I found one said 416 dollars is that right?

 

[Axix23]

Here is some stuff from the owners manual

 

[Dannyvandelft]

Here is some stuff from the owners manual

Didn't see that one, guess I'll be relocating my leads lol.

 

[Axix23]

Didn't see that one, guess I'll be relocating my leads lol.

i mean you could be fine. Lol it’s probably for morons accidentally touching the wrong cables with wrong polarity. Lol ?
The front posts are a lot farther away so it’s harder to do that. Lol

 

[Dannyvandelft]

i mean you could be fine. Lol it’s probably for morons accidentally touching the wrong cables with wrong polarity. Lol ?
The front posts are a lot farther away so it’s harder to do that. Lol

Yeah I think they don't want people putting the negative straight to the battery. That'll mess shit up. I always put the negative to a chassis bolt. That way the circuit goes through the car.

 

[consultadrone]

From the Toyota (BMW) Workshop Manual regarding charging the battery.

 

[Bundy]

Lol it’s probably for morons accidentally touching the wrong cables with wrong polarity. Lol ?

I think it is a bit more to it than that

"The IBS is a mechatronic component for monitoring the battery condition. The IBS is secured and connected to the negative terminal of the battery. The power supply for the IBS is fed across a separate cable. For data transmission, the IBS is connected to the DME (Digital Engine Electronics) or DDE (Digital Diesel Electronics) via the BSD (bit-serial data interface). Also the BSD is tied into the alternator and does several things.

On vehicles with IBS, recharging the battery directly at the battery terminals could lead to a misinterpretation of the battery condition and even unwanted Check-Control messages or fault memory entries.

If the battery is recharged while installed, it must be recharged using the jump-starting points in the engine compartment.
Only then can you be sure that the recharging is correctly recognized by the vehicle electronics on vehicles with intelligent battery sensor (IBS)"

 

[Lilchief]

So can I use CTEK to keep my car charged when not in use if plugged right?

 

[Hexel]

Yes

 

[Lilchief]

Finally got my ctek Msx 5.0.... before I hook it up to my Supra is there anything I need to do? AMG mode?

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