Do I have the correct location for the E39 battery safety terminal explosive charge?

bluebee · Sep 22, 2011

Just curious, where is the battery disconnect explosive charge in this picture?

I searched the bestlinks, and found only this:
- How the battery disconnect explosive charge works in an accident (1)

But there were no pictures of the location of the explosive charge in that thread.

I ran a 'regular' search for "explosive charge" and "explosive battery disconnect" (and a few others), most of which got tons of threads, but, scrolling through the first few pages showed no picture of the location of the explosive device itself.

Realoem had this (but again, no explosive charge):

Googling for "E39 battery explosive charge" I find the term "battery safety terminal", which, further googling, gets me this "BST" E90 thread:
- Battery Safety Terminal exploded & disconnect the starter cable

From that, can I 'surmise' that the picture below of my E39 has the correct location for the BST circled?

Also, what is that white plastic box for that is just above the battery?

JimLev · Sep 22, 2011

The explosive caharge is on the positive cable just past the clamp. See the small wires, they detonate the charge.
The white cover has more big amp fuses (50 to 100 amp) behind it......don't you have a Bentleys?

bluebee · Sep 22, 2011

JimLev said:
See the small wires, they detonate the charge.

I don't actually see the small wire in my own pictures so I'll have to check tomorrow in the daylight. I do see two large wires.

JimLev said:
don't you have a Bentleys?

I'm sorry. I didn't think to look there. Most of the time, I find the Bentleys almost useless.
- Are the Bentleys nearly as useless to you as they are for me?

I do have the paper & PDF Bentleys. PDF is vastly easier to search. Page 121.3 has the first mention of the Battery Safety Terminal (repeated at page 400-9).

Page 121-10 shows another diagram of the BST:

rdl said:
The explosive disconnect is the circled "BST" in your picture.

Thanks. I found it. Here it is in my 2002 E39 just after I replaced the battery:

JimLev said:
The white cover has more big amp fuses (50 to 100 amp) behind it......

Ah. I had thought there were only 4 fusebox locations in the E39.

This tells me there are five!

Glovebox
Passenger side filter ebox
Passenger side underseat carpet
Trunk battery compartment panel 1
Trunk battery compartment panel 2

I'm trying to map out all my fuses, one by one, to put them in a spreadsheet. The first task is finding them; the main task, after that, will be to identify the purpose & amperage of each one (and to make sure I have a spare on hand for each).

rdl said:
The white cover with the arrow "what is this?" is a fuse box for F100 -> F106

Thanks. So far I've only identified F46 -> F66 (although I'm not sure what an 'onboard monitor' is just yet as there is absolutely no mention of it in the Bentleys).

rdl · Sep 22, 2011

The explosive disconnect is the circled "BST" in you picture. It's triggered by the MRS (airbag/seatbelt/etc) module in the event of an accident.

The white cover with the arrow "what is this?" is a fuse box for F100 -> F106

Regards
RDL

bluebee · Sep 22, 2011

I didn't find any pictures of activated E39 BSTs, but here's an E60:

bluebee · Sep 24, 2011

Here is a nice pic, from JimLev, of the high-amperage fuses (fusible links?) under the white cover above the battery:

And, older E39s apparently have four relays (instead of the three that I have):

Rear window defogger relay
Central locking relay
Unloader relay,
Fuel pump relay <== only in older E39s

bluebee · Mar 9, 2013

For reference, RDL added a nice diagram of G19 explosive disconnect over here today:

rdl said:
The explosive safety disconnect is intact if the car starts without a jump at the engine bay post.

When activated (i.e. discharged to sever the circuit) it cuts the circuit running from the battery's +ve post to the starter, engine bay jump start post and alternator => impossible to start the car from the battery.

For those interested, the safety disconnect is located on the +ve battery terminal. Item G19 on the locator picture from WDS.

Whorse · Mar 10, 2013

If I removed the explosive charge would any sensor be aware of it and give me an airbag light or something? Here in New york Ive had people hit me and run and luckily I was in older vehicles that I would be able to drive (even with 3 wheels) long enough to get a license plates or view of the driver. One time I was in and accident where if i didn't get the car moved there would of been a 10 car pile up. I drove my e30 with the frame rail wrapped around the alternator and the motor pointing to the right about 25degrees. In an e39 I'm "Dead" in the water. or **** out of luck if i get rear ended and the airbags go off breaking my face and then killing the engine while the scumbag in his 1988 toyota drives off.

JimLev · Mar 10, 2013

Hi Whorse, haven't seen you around for a while.
Don't think anyone has ever asked that question before.
You could try unplugging the little connector that detonates the charge and see if it gives you a fault.

bluebee · Mar 10, 2013

JimLev said:
You could try unplugging the little connector that detonates the charge

Just curious ... do you mean unplugging this little connector in the blue circle?

Does that go to connector X1770? Is it in any of the photos in this thread?

It's hard to visualize what the explosive charge is connected to from these pictures [ before it goes to the MRS (airbag/seatbelt/etc) module ].

bluebee · Apr 26, 2013

For the record, the BST activated in an accident recently and the user's thread was updated today with nice videos explaining the BST:

Fudman said:
It's called the battery safety terminal (BST). See this:

http://www.bimmerfest.com/forums/showthread.php?t=570030

See also:
- Where to find the battery explosive charge emergency quick disconnect (1) (2)

bluebee · Nov 26, 2013

For the record, we might get a good picture of an exploded BST from this thread today:
> E39 (1997 - 2003) > E39 Shorted Alternator Lead

youngnotold said:
bartelbe,
Thank you. I had just posted a new thread about the location of that cable. Do you think it is possible I set off the BST when I shorted the alternator lead? Anyway, thank you for the help. I was going to say that searching for that cable in a cold garage in Ohio is no fun. But, then see where you are from MN. 27 f now seems tropical !

bluebee · Feb 2, 2014

Sometimes I wonder why people ask questions, and receive help, and never post a picture when asked. sigh.

Anyway, Saint Q posted a nice graphic of the BST today, over here:

bluebee · Feb 22, 2015

This thread today has good information about the cables and BST ...
> E39 (1997 - 2003) > Melted '00 528iT battery cable to fuse / relay panel ...

bluebee · Apr 14, 2015

Found this nice diagram in this thread today, which should be relevant to the E39 also...
> E46 (1999 - 2006) > Body electrics pdf

mikesmith2 said:
May be useful for diagnosing body electrics

http://www.bmwtech.ru/pdf/e46/ST034/4 Central Body Electronics Internet.pdf

gmak2012 · Apr 14, 2015

Two phrases that I don't like to see on the same page: "Battery", and "Explosive Charge". Someone has got to screen the weed that these German engineers are smoking in their bull-pit sessions.

HTK12 · Apr 14, 2015

Or maybe you should watch less hollywood movies. The BST has explosive charge that is only enough to push out the tapered end on the cable from the battery terminal. It's like saying I don't like to sit behind of a an explosive charge while driving..

bluebee · May 26, 2015

Looks like someone reported airbag codes due to a BST that looked good today...
> E46 (1999 - 2006) > BST terminal question

SWAMPER said:
BST cable problem
Wife's 2001 325i wagon tossed a SRS code so I got the peak srs code tool and pulled the code and was a ob code battery safety firing switch 1 (something like that) and the search came up as the BST terminal on the positive terminal of battery, car runs fine with code on and the terminal does not seem to have blown apart from what I can see, so I cleared the code and it stayed off for about a week then came back on so question is can this BST fail without blowing ? damn thing is a crazy cost and don't think the repair kit is available anymore for them, did see a video where a guy took a known good one and took the terminal end off the cable and replaced it on the cable on the car …. Any help would be great

bluebee · May 26, 2015

I noticed, while researching the BST, that a bunch of the E46 guys ask questions about an unused two-wire connector (unattached) near the BST ...
> E46 (1999 - 2006) > Unused electrical connector in battery compartment

kimmy said:
I pulled the cover on the battery to check it out and noticed that there is a small (two conductor) electrical connector hanging along the wall near the positive terminal. Looks like it is intended for some uninstalled accessory or such. Any one have any idea what it is for?

> E46 (1999 - 2006) > What exactly is this connector (battery) for?

Jitty said:
I recently bought a 2001 e46 325i Sedan and am working on a few projects with it.

Currently, I'm working on installing one of my Alpine Type-S 10" subs out of my Prelude before I sell it. A couple problems have risen up, so I'll lay them out there.

It looks awful. Put simply, I want to keep the stock head unit in, and install almost all of the Alpine product that I dropped 1.5k$ on in 2004ish. However, the Alpine H/U I have looks so tacky (blue against orange), it's unbelievable. I'm willing to live with just CDs and no ipod or aux connections, but I'm not sure if this stock unit has prewiring for an amp/sub. I found a connector in the trunk of the vehicle with the letters AMP 6 905 977 written across it. Google doesn't bring up too much, as I'm not really sure what to call it. I connected test wires to it without chopping the connector, but could pull no sound from it.

Below is a low res picture of it, the area is directly beside the battery. The connector in question is the un-connected one at the top of the pictures. Google tells me this is prewiring for either an amplifier or a CD changer, I can't tell which. I tried searching here, but all I learned is that DSC doesn't turn off with a single press. I also found a similar such connector underneath the rear seat cushions when I was reupholstering them.

I have the original sales flyer for the vehicle, and as it seems, I have the premium package, and do not have the sport nor the cold weather one. I do not believe the HK upgrade system was in it, if that is relevant.

> E46 (1999 - 2006) > Question) Near Battery, there is a small black connector

bryankang said:
Hi, what is a small black connector for? That is hanging near battery?
I found it was disconnected, but I have no idea what is this for.
Anyone who have an idea? Thanks.

> E46 (1999 - 2006) > battery cable/connector

aioros said:
I recently changed the battery due to bad cells and had to change the alternator. I noticed this cable being loose, does anybody know what's for and where it should go?

> E46 (1999 - 2006) > Just changed my first battery - question about "spare" wire with connector

dynosor said:
I just changed the OEM battery in my 330i after almost 6 years for an exide that seems to fit and work fine. The question is, does anyone know what the thin wire is with a two-pin connector that hangs near the positive cable?

I didn't notice it until I removed the old battery and then spent a while trying to figure out if it needed to plug in some place.

Due to its proximity with the pyro terminal disconnect on the positive cable, I think it may be a test port for verifying a new pyro device without setting it off.

Car seems fine with this wire hanging in the breeze, so I am just curious.
Any ideas?

And, the answer is ...

luke320 said:
I think they are use during shipping from Germany.

MMME30W said:
I think the conclusion was it was for the connector for the trickle charger for when they put the cars on the boat.

Jitty said:
Ah, I found from Googling the connector in the rear seat that it's used for disabling the battery during shipping. I guess I'm stuck with ricer blue in my interior then.

Lbert said:
I remember someone mentioned that connector is used during shipment to trickle charge the battery.

bluebee · Jul 1, 2015

The topic of the smaller wire came up again today, over here...
> E39 (1997 - 2003) > Negative battery cable stuck on terminal?

VNguyen09 said:
Hey guys, so last week I had a slight fender bender on the way to work, long story short I somehow ended up "sitting" on top of the hood of an 8th gen Civic. After everything was said and done I got back in my car turned her back on and "Check Turn Signal" message popped up (Somehow the force of the accident blew out my passenger side angel eyes).
In my attempts to find that small issue I ended up trying to pull the battery to see if the error would go away. So my issue goes, the negative cable on my battery will spin (with a small amount of force) on the terminal but seemingly will not lift out. I'm fairly confused as to what could have happened to my negative terminal?
Thanks

Do I have the correct location for the E39 battery safety terminal explosive charge?

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