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BMW PHEV: Safety fuse replacement is extremely expensive

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Re: BMW PHEV: Safety fuse replacement is extremely expensive

#291

Post by jacquesm »

idiotsecant wrote: post #287
jinzo wrote: post #269

Earlier quoted context omitted.

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.

Pyrofuse will definitely blow on overcurrent.

Usually not by itself though, and if it does that makes it a hybrid fuse, one that has both a pyrotechnical disconnector and a thermal/overcurrent one.

Re: BMW PHEV: Safety fuse replacement is extremely expensive

#292

Post by bluGill »

dyauspitr wrote: post #192
Scoundreller wrote: post #107

Earlier quoted context omitted.

Sadly, they’re close to 100% caught up to automatic transmissions in North America.

Are you advocating for manual transmissions?

In european cars for sure. They don'tilike autos there so they are an afterthought.

though it also means nobody will steal my truck in the us as who can drive it?

Re: BMW PHEV: Safety fuse replacement is extremely expensive

#293

Post by amelius »

Glawen wrote: post #289
jinzo wrote: post #261

Earlier quoted context omitted.

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 ch…

Do you realise how difficult it is to get "electrocuted" in a battery powered vehicle ? I suggest you document yourself on the matter. The only real issue in reality is thermal runaway

Yeah, what is the max voltage of these batteries?

Re: BMW PHEV: Safety fuse replacement is extremely expensive

#294

Post by potato3732842 »

jinzo wrote: post #166
CraigJPerry wrote: post #124

€4000 euros plus tax to replace the module that contains the fuse. Insane. The ford transit custom PHEV costs £4500 to replace the timing belt. Access issues mean dropping the hybrid battery and parts of the sub frame. Compare with the mk8 transit, i've done the wet belt myself on that and it requires no special tools (well, i bought a specific crank pulley puller for £20) and can be done in a day on the driveway. I…

Is it insane? I'm working in this field, and I know how quickly you can come up with such a number if you are BMW and you are deathly afraid that someone will get electrocuted while working on your car, driving it or rescuing someone in a crash. It's a safety and liability issue, where they go to great lengths to actually re-certify a battery after crash. The whole thing is setup so, that even the dummy electricians…

You, you are the problem.

It's not excusable to do this to the product because of some hand wavey napkin math about liability.

Understand how people will interact with your product and then use that information to avoid doing things like routing power where firefighters want to cut and you'll accomplish the same thing without a stupid expensive hair trigger fuse.

Re: BMW PHEV: Safety fuse replacement is extremely expensive

#295

Post by ricardobeat »

jinzo wrote: post #261
jacquesm wrote: post #240

Earlier quoted context omitted.

> 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.

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 ch…

They mention in the article that replacing the same fuse on a Tesla cost €11.

Re: BMW PHEV: Safety fuse replacement is extremely expensive

#296

Post by potato3732842 »

lazide wrote: post #228
jacquesm wrote: post #206

Earlier quoted context omitted.

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…

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.

Then why name it a goddamn fuse then?

Re: BMW PHEV: Safety fuse replacement is extremely expensive

#297

Post by close04 »

jinzo wrote: post #264
close04 wrote: post #256

Earlier quoted context omitted.

> 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 ea…

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.

> Yes, as changing a tire is completely the same tool-and-knowledge level than repairing a EV Battery.

I think you are intentionally misrepresenting this and moving the goalposts to make your point. GP blamed safety and liability for the way the process looks like, not the complexity of the task. When it comes to safety you bet that an improperly installed or inspected wheel or tire can be dangerous.

A short internet search tells me [1][2] that some sort of tire malfunction causes tens of thousands of accidents and kills hundreds of people every year in the US alone. That doesn't include wheel malfunctions (e.g. wheel coming off). Yet this isn't locked behind some manufacturer approval and proprietary tools.

How BMW chose to approach this is profit driven. The old money printing machine from ICE maintenance, repairs, and spare parts is slowing down so they come up with new ways of extracting money. Like making the lives harder and more expensive for any non-BMW shop to do repairs. They're not alone in this, other brands do the same.

> If you would see how EV Clinic "repairs" Tesla batteries, you would not say they have any concern for liability.

More moving of goalposts mixed with not understanding what liability is, and where it belongs. So you tell me what's Tesla's liability when EV Clinic "repairs" a battery.

[1] https://www.smithlawcenter.com/practice-areas/defective-tire...

[2] https://www.safetyresearch.net/nhtsa-gets-real-on-tire-fatal...

Re: BMW PHEV: Safety fuse replacement is extremely expensive

#298

Post by jacquesm »

amelius wrote: post #293
Glawen wrote: post #289

Earlier quoted context omitted.

Do you realise how difficult it is to get "electrocuted" in a battery powered vehicle ? I suggest you document yourself on the matter. The only real issue in reality is thermal runaway

Yeah, what is the max voltage of these batteries?

Depends on the brand and the model, there is a trend towards higher voltages because that implies lower currents and wiring is heavy and expensive.

It started out with (nominally, voltage can rise and fall based on charge levels) (30S) 144V packs, (96S) 352V is very common and there are (192S) packs that do 704V (but that are marketed as 400V and 800V respectively).

You don't want to get zapped by any of these, it's middle voltage DC which is quite dangerous, so the fuses definitely have a safety aspect in case of a crash, they are to protect emergency personnel from touching the frame and exposed wiring. But that's in case of a very serious crash, your average encounter with a rabbit might set off the crash detector (which can't really know ahead of time how bad a crash will be) but has extremely little chance of resulting in exposed wiring. In the case of BMW that rabbit could end up being pretty expensive.

Re: BMW PHEV: Safety fuse replacement is extremely expensive

#299

Post by potato3732842 »

TylerE wrote: post #226
lionkor wrote: post #205

Earlier quoted context omitted.

> Most people need a recommendation for something more current Bless them, I would rather buy 10 shitboxes than one modern car (and that cost is about the same).

I’d rather not die in a very survivable crash.

Pretty much every major safety feature is an order of magnitude less meaningful than the last.

If you wear a seatbelt and eschew the most risky driving behaviors your chances of getting in a crash where the difference between 2005 and 2025 matters are very, very, very, small.

Re: BMW PHEV: Safety fuse replacement is extremely expensive

#300

Post by chakintosh »

jinzo wrote: post #278
cjrp wrote: post #198

Earlier quoted context omitted.

Interestingly I’ve seen YouTubers replace the fuse in a Tesla for about £40 and a few hours of labour (it’s under the rear seats). Maybe something they’re doing right.

You can replace the fuse (not that easly) but for approximately the same price in a BMW. You do have to put in more work but the problem is with re-certifying the battery. Tesla does not care if the battery was damaged in the crash, they will (more or less) happily re-enable it. BMW decided that the only safe way is to re-certify the whole battery. I'm not saying it's the right decision, I think they over did it and…

> they will (more or less) happily re-enable it.

That's one more car they will happily milk for a subscription. Also, safety laws in the US are way more lax than Europe.

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