Comment by jacquesm
11 hours ago
Yes, it is insane. It's a fuse. They must have some stats on how often those things need replacing and it should have been accessible. The customer has - when they buy the car - absolutely no way of knowing what kind of surprises like this there are hidden in the vehicle and besides, it kills the second hand market so you can only trade your vehicle to a BMW dealership where they can absorb those costs for a fraction of what it will cost an end user. BMW is a crap brand in spite of their reputation, we've had one leased Mini in our company and it is the very last time we do business with BMW, that thing was more in the shop than out of it with electrical issues. A friend had pretty much every BMW ever made since he got wealthy enough to afford them (car enthusiast) and his experience is much the same, but he keeps buying them.
They have no stats because the entire platform is new and different. I would guess they have a very poor prediction model.
It’s not a fuse. It’s a fuse plus guarantee plus liability.
> It’s a fuse plus guarantee plus liability.
This is BMW we're talking about. Their guarantees are worth absolutely nothing if my experience is anything to go by and them accepting liability is not something you should have to pay 4K for if other brands can do the same thing under $100.
They'll refuse warranty on the XDrive if you don't use approved brand and model of tyres so... my bet is on them wanting to extort all the precious money they can from their poor customers
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I'm sure it depends on market, but I also know 100% that if they will certify the battery as safe, and then you get electrocuted when entering your car because the battery was not safe - they will be on the hook, in all developed markets. No one else, that cares about people safety, do the same thing for under $100. Even Tesla, that almost completely disregards any safety - be it "Full Self Driving" or "let's just change this, without checking if the battery is actually safe", does not do it under $100.
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> It’s a fuse plus guarantee plus liability.
If that was the issue you wouldn't be allowed to change your wheels on the side of the road. They'd be locked down to the car and require a complex software procedure to guarantee they were swapped correctly and won't endanger lives.
This is a professional shop raising the issues. They are liable for how the repair is done. BMW is just liable to lose money if people can easily fix their car at some other, cheaper, professional garage.
Yes, as changing a tire is completely the same tool-and-knowledge level than repairing a EV Battery.
If you would see how EV Clinic "repairs" Tesla batteries, you would not say they have any concern for liability.
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Fuses are not items that should be replaced normally - they are self-destroying emergency protections for the electrical system.
If it is protecting that end users can plug arbitrary loads into, that is one thing - but this doesn’t sound like that?
Why did that fuse blow? Because if that is not addressed, it’s likely to just blow again.
I think the people that replace fuses are aware of the potential issues around them. The article - which I'm sure you've read so don't take this as commentary on your comment - details that in other electric vehicles, for instance Tesla this is handled quite differently:
"While Tesla’s pyrofuse costs €11 and the BMS reset is around 50€, allowing the car to be safely restored, BMW’s approach borders on illogical engineering, with no benefit to safety, no benefit to anti-theft protection — the only outcome is the generation of billable labour hours and massive amounts of needless electronic/lithium waste."
It's not a choice between 'ridiculously inaccessible with the potential to create more damage than your car is worth' and 'push to reset'. There are many options in between, some of which would be a happy medium between the two that protect both safety, the environment and the customers' wallet. Which BMW's solution clearly isn't.
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This fuse blows because a crash was detected and it is to protect the people inside the car and rescuers. The article argument is that it can blow even for small crashes where no damage to the battery occurs but rehabilitating the vehicle still incurs an outrageous cost. This is not a simple over current protection fuse.
$1000 for the module with the fuse seems ok to me. Another $3000 to link the module to the vehicle is the outrageous part.
They are not only linking it to the vehicle, they are doing a LOT of other checks on the battery - that it's not damaged in non-obvious ways. For that you need trained people (it's really high voltage and amperage stuff), tooling AND you really need to be sure you guarantee everything is OK.
Even the basic mechanical disconnect and lowering of the battery is far from simple (and requires A LOT more expensive tools than changing a wet belt - not because they are greedy, but because a lift that can lower such hevy battery costs a lot of money, mostly in materials), and that's not even opening it, making sure you don't get electrocuted when you work on it ect.
> Fuses are not items that should be replaced normally - they are self-destroying emergency protections for the electrical system.
Next time when the fuse switch in my home I'll buy new home. I shouldn't normally switch on auto-fuse again!
Fuse blows, so you know something went wrong, you check corresponding part, fix it, and enable/change fuse. Nothing special. In home perspective - it could be plugging too many energy needy receivers into one outlet.
That is literally exactly what I’m saying.
In that situation, if you bypassed the fuse, or just kept replacing them without figuring out why it blew (too much load on a specific circuit), you very well might burn your house down by catching the wiring inside your walls on fire.
If it’s something that it is easy to connect loads too, then that is probably not super unusual and easy to fix, because people do that all the time, and you know what is happening and how to fix it. But you do need to fix it.
If it isn’t, then that is very concerning, because something caused that overload, and without that fuse your wires would have caught on fire instead of the fuse blowing. Inside your walls.
Either way, fuses are an emergency measure to stop the wires from destroying themselves from overload. They are destroyed in the process of saving your wires.
And if you are doing this all the time? You’ve got a very big problem brewing.
Ladies and gentlemen - behold the perfect consumer
The article gave examples for why the fuse blows - it falsely thinks the vehicle was in an accident and trips. Hitting a pothole or a rabbit.
It is unlikely to blow again under normal use.
Then why name it a goddamn fuse then?
Yep, might be there was a known issue that was addressed, at which put in a new one. But just replacing a fuse (or, simultaneously worse and better, just resetting a breaker) without further investigation is just kicking a very spicy can down the road.
I had a doozy of a trip issue on one project, a motor would occasionally (not always, no real pattern, hot/cold/etc. didn’t matter) trip the breaker, requiring a sparky to come out and open up the panel to reset it. We tried a bunch of things, megger-ing the motor, testing peak startup current on each phase with a fancy meter, checking phase-to-neutral current (Larger than you’d think! But this was normal, apparently.)
Everything was normal. In the end all we could think something was weird about the contactor. They took it out (I was off site at the time) and took it down to the substation to test it out.
With three phases connected to the contactor (and nothing connected on the other side) they energised the coil, and with an almighty bang it tripped the main incomer and took the entire sub offline.
Turns out there was a manufacturing defect in the contactor and sometimes for a millisecond, if the phase of the moon was right, it dead shorted two phases.
So there, even when you know everything, you don’t know everything.
Fuses are necessary on any electrical system, and especially in a car, which is an electrical shitshow (floating ground, high-voltage and high-frequency interference), fuses blow all the time. Granted, usually on a well-maintained and new car it happens very rarely, but saying that it's a catastrophic and concerning event is dumb.
This is a pyrofuse, it does not blow with overcurrent as regular fuse, but blows in the same way airbags blow - when detecting a crash. We can debate if they blow too quick, but if you are designing this system - where and truly lives can be in danger, you would probably err on the side of caution too.
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What sort of cars do you drive?
I’ve never had a fuse blow on a car less than 20 years old, and then it was due to shorts due to damaged insulation and bad grounds due to corrosion, which are legit problems that need to be corrected.
Also, unlike breakers, fuses are generally immune to issues with HF interference and the like - they work through basic thermoelectric effects which iron out all but the most extreme issues. If you’re moving multiple amps in a situation described as ‘RF’, or ‘high frequency’ in a DC system that’s not just noise!
That’s a real problem that needs fixing!
Not fixing the underlying problem behind a blown fuse (or constantly tripping breaker) is how your car (or house or whatever) burns to the ground.
Or you have a Lucas, in which case my condolences.
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