zlacker

[return to "BMW PHEV: Safety fuse replacement is extremely expensive"]
1. CraigJ+is[view] [source] 2025-12-05 06:22:04
>>mikela+(OP)
€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 believe in some markets the replacement schedule is down to 6 years for the new phev due to all the wet belt failures on older models.

So far my favourite brand to work on has been Mazda, the engineering is very thoughtfully done with consideration for repairs.

I hear a lot of praise for toyota but it's from people who haven't worked on a car themselves rather than mechanics and they must be talking about toyotas from a bygone era because i'm not impressed with a 2019 corolla engineering at all, specifically various parts of the electrical system. I believe that was the most popular car in the world at that time.

Tesla is remarkably well done. Simplicity is under rated. So much so i bought one with the intention to keep for a looooong time.

◧◩
2. jinzo+8A[view] [source] 2025-12-05 08:00:39
>>CraigJ+is
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 in an average BMW shop can safely certify that this battery is still safe. It's a lot easier to kill yourself (or someone else) when working on a EV Battery than wet belt. Also a lot harder to repair said battery than wet belt. And that goes for all EVs and manufacturers that actually care about people (Tesla, demonstrably does not).
◧◩◪
3. jacque+PQ[view] [source] 2025-12-05 09:28:19
>>jinzo+8A
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.
◧◩◪◨
4. taneq+0X[view] [source] 2025-12-05 10:09:10
>>jacque+PQ
It’s not a fuse. It’s a fuse plus guarantee plus liability.
◧◩◪◨⬒
5. jacque+2Y[view] [source] 2025-12-05 10:19:42
>>taneq+0X
> 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.

◧◩◪◨⬒⬓
6. jinzo+S21[view] [source] 2025-12-05 10:59:16
>>jacque+2Y
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.
◧◩◪◨⬒⬓⬔
7. Glawen+wg1[view] [source] 2025-12-05 12:39:47
>>jinzo+S21
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

◧◩◪◨⬒⬓⬔⧯
8. ameliu+Zk1[view] [source] 2025-12-05 13:06:44
>>Glawen+wg1
Yeah, what is the max voltage of these batteries?
◧◩◪◨⬒⬓⬔⧯▣
9. jacque+Xm1[view] [source] 2025-12-05 13:18:40
>>ameliu+Zk1
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.

◧◩◪◨⬒⬓⬔⧯▣▦
10. ameliu+1o1[view] [source] 2025-12-05 13:25:11
>>jacque+Xm1
Yikes, that sounds dangerous.

I'd personally prefer e.g. 48V even if that meant some more losses and/or thicker cables.

◧◩◪◨⬒⬓⬔⧯▣▦▧
11. Kirby6+Fz1[view] [source] 2025-12-05 14:25:12
>>ameliu+1o1
Running an EV off 48V would lead to a heavily, heavily compromised vehicle. There just aren’t components that can handle 5-10kA of current with a reasonable size.
◧◩◪◨⬒⬓⬔⧯▣▦▧▨
12. ameliu+ZM1[view] [source] 2025-12-05 15:24:30
>>Kirby6+Fz1
What parts of the car need that amount of current?

Are you talking about the charging circuitry?

What are the requirements for the motor(s)?

[go to top]