Battery fire

[Andy665]

Well maintained car but things can still happen. Pulled up outside home last night and there was a distinctly off smell coming from the back of my wifes BMW F11 535d.

Opened the tailgate and there was smoke coming from under the boot floor, lifted it slightly to see the battery on fire.

No damage to the car other than to wiring and obviously the battery is destroyed but if I was not as careful as to always make sure all of our cars have a fire extinguisher in them it could have been a whole lot worse.

No idea of the cause but suspect something to do with the stupidly complex electronics that BMW seem to stuff around the terminals

If you only buy one thing over the coming week make sure its a fire extinguisher for each of your cars - £10-15 very well spent

[speedking31]

Is Yuasa an OEM battery brand for BMW?

[shtu]

speedking31 said:

Is Yuasa an OEM battery brand for BMW?

Do you work for BMW's warranty dept or something?

[DaveCWK]

That's not a small fire!

I think i'd be taking the car to a BMW specialist for them to have a look, see if they can pick through the charred mess, compare it to an in-tact car & figure out what the cause was.
I doubt a simple loose terminal would do that - it would overheat when under load like when starting the engine, not just returning home.

[SteveR1979]

Not had a new battery recentlyish has it??

Wondering if its been replaced and the car not coded, and so the battery has been over charged

[Krikkit]

speedking31 said:

Is Yuasa an OEM battery brand for BMW?

Irrelevant, they make quality gear.

[Andy665]

SteveR1979 said:

Not had a new battery recentlyish has it??

Wondering if its been replaced and the car not coded, and so the battery has been over charged

Battery was replaced about 3 months before I bought the car, so its about 16 months old - its been coded

In the hands of insurance now so leaving to them to get it repaired, assuming they do not write it off, I'm assuming not but you never can second guess insurers

[chris116]

That's a bit of a sobering sight, lucky the rear trim didn't go up.

[CloudStuff]

chris116 said:

That's a bit of a sobering sight, lucky the rear trim didn't go up.

Far too close to the fuel tank for comfort too!

[Andy665]

chris116 said:

That's a bit of a sobering sight, lucky the rear trim didn't go up.

I'm considering myself pretty lucky, rear trim is unmarked, the tray that sits under the boot floor is toast, the battery is obviously toast and so is the wiring, not even even paint bubbling in the battery compartment.

I reckon I was about 30 seconds away from it going up completely, lifting the boot floor to use the extinguisher the flames were 2ft high and it had really caught - so relieved I had easy access to a fire extinguisher

Edited by Andy665 on Thursday 22 December 10:41

[The test driver]

Is that a melted screwdriver stuck in there?

That's not a battery fire, the junction block on top has gone up and melted on to the battery. Hard to say without being able to inspect it but a short to ground or the cable passing under the battery bracket look a little suspicious.

[The Wookie]

BMW have issued quite a few recalls around battery wiring on other models, I’d suggest it’s more likely there’s been a poor connection, it’s overheated and set the battery alight

[Andy665]

The test driver said:

Is that a melted screwdriver stuck in there?

Yes, that was sitting in the shallow storage tray between the boot floor and the battery compartment, will have fallen through when the tray melted

The test driver said:

That's not a battery fire, the junction block on top has gone up and melted on to the battery. Hard to say without being able to inspect it but a short to ground or the cable passing under the battery bracket look a little suspicious.

On going out and looking at it again you are right, it is the junction box as the battery and its casing are intact

Edited by Andy665 on Thursday 22 December 11:32

[kylos27]

People keep buying German cars knowing full well how over complicated they are . Why?

[Limpet]

speedking31 said:

Is Yuasa an OEM battery brand for BMW?

I'd be astonished if that had any relevance to what happened here. Yuasa batteries are top notch, for both car and motorcycles.

[TooLateForAName]

The Wookie said:

BMW have issued quite a few recalls around battery wiring on other models, I’d suggest it’s more likely there’s been a poor connection, it’s overheated and set the battery alight

this.

At one time I seemed to be getting a danger! recall! notice every month for my e90 3 series.

Shame they were all for electrical issues that had already happened to me.

Of course then the timing chain snapped so all irrelevant now.

[normalbloke]

That’s the end of that car then!

[Ransoman]

That's not a battery fire, that's a fusebox fire. Overspecced fuse from the factory or a fault in the live wiring causing too much current draw?

[Draxindustries1]

CloudStuff said:

chris116 said:

That's a bit of a sobering sight, lucky the rear trim didn't go up.

Far too close to the fuel tank for comfort too!

It's a 535D, little chance of a fuel fire..

[996TT02]

Limpet said:

speedking31 said:

Is Yuasa an OEM battery brand for BMW?

I'd be astonished if that had any relevance to what happened here. Yuasa batteries are top notch, for both car and motorcycles.

And a lead-acid battery under normal conditions filled mostly with water and one third acid can never really burn.