6 ms·

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

by jinzo 10mo ago

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.

jacquesm 10mo ago
Given that I've tried to hold BMW to their warranty and was shafted I would not bet on that.
- semanticist 10mo ago
  There's a difference between BMW ignoring their warranty and who gets found liable during the wrongful death lawsuit after the mechanic gets electrocuted due to poor/unsafe EV design. I'm sure BMW would love to not be liable in those cases if they could just decide not to be liable, but inspections and fuses presumably turn out to be cheaper than the settlements they'd otherwise be paying.
Glawen 10mo ago
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
- amelius 10mo ago
  Yeah, what is the max voltage of these batteries?
  - jacquesm 10mo ago
    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.
    - amelius 10mo ago
      Yikes, that sounds dangerous. I'd personally prefer e.g. 48V even if that meant some more losses and/or thicker cables.
      - Kirby64 10mo ago
        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.
        amelius 10mo ago
        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)?
        jandrese 10mo ago
        Charging speed is directly related to the voltage of the pack. Even if your own vehicle had arm-thick cables to support high speed charging at 48v there is no quick charger in the world that could support it. You would be stuck in the bad old days of needing hours to recharge the battery on your EV.
- jinzo 10mo ago
  What are you talking about? Yes I know how quickly I can get electrocuted when the battery pack is open. I just need to touch two exposed busbars ~30cm apart. Or my tool needs to touch them.
  - Tostino 10mo ago
    I disagree with your other takes in this thread, but you are 100% right here. This is dangerous stuff that needs to be treated with respect. I don't think it should be locked away to just the MFG, but it does need to be respected.
  - Glawen 10mo ago
    Exactly, you need to touch both plus and minus. You moved the goalpost from getting electrocuted driving your car due to shoddy quality remanufacturing of battery, to getting electrocuted while repairing the high voltage side of your vehicle. Remanufacturing quality does not come into play if you decide to touch plus and minus side of a HV battery.
    - jinzo 10mo ago
      Sorry I have no idea about this goalpost moving, maybe it's a language barrier. I'm just saying working on it is quite dangerous. But you can easily get electrocuted by shoddy remanufacturing (especially if someone drilled into the battery to replace a single cell - as EV Clinic shows in their videos), that's why there are additional safeties with regards to bad isolation. So I stand by both takes.
ricardobeat 10mo ago
They mention in the article that replacing the same fuse on a Tesla cost €11.

by jinzo 10mo ago

jacquesm 10mo ago

Given that I've tried to hold BMW to their warranty and was shafted I would not bet on that.

semanticist 10mo ago
There's a difference between BMW ignoring their warranty and who gets found liable during the wrongful death lawsuit after the mechanic gets electrocuted due to poor/unsafe EV design. I'm sure BMW would love to not be liable in those cases if they could just decide not to be liable, but inspections and fuses presumably turn out to be cheaper than the settlements they'd otherwise be paying.

Glawen 10mo ago

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

amelius 10mo ago
Yeah, what is the max voltage of these batteries?
- jacquesm 10mo ago
  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.
  - amelius 10mo ago
    Yikes, that sounds dangerous. I'd personally prefer e.g. 48V even if that meant some more losses and/or thicker cables.
    - Kirby64 10mo ago
      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.
      - amelius 10mo ago
        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)?
        jandrese 10mo ago
        Charging speed is directly related to the voltage of the pack. Even if your own vehicle had arm-thick cables to support high speed charging at 48v there is no quick charger in the world that could support it. You would be stuck in the bad old days of needing hours to recharge the battery on your EV.
jinzo 10mo ago
What are you talking about? Yes I know how quickly I can get electrocuted when the battery pack is open. I just need to touch two exposed busbars ~30cm apart. Or my tool needs to touch them.
- Tostino 10mo ago
  I disagree with your other takes in this thread, but you are 100% right here. This is dangerous stuff that needs to be treated with respect. I don't think it should be locked away to just the MFG, but it does need to be respected.
- Glawen 10mo ago
  Exactly, you need to touch both plus and minus. You moved the goalpost from getting electrocuted driving your car due to shoddy quality remanufacturing of battery, to getting electrocuted while repairing the high voltage side of your vehicle. Remanufacturing quality does not come into play if you decide to touch plus and minus side of a HV battery.
  - jinzo 10mo ago
    Sorry I have no idea about this goalpost moving, maybe it's a language barrier. I'm just saying working on it is quite dangerous. But you can easily get electrocuted by shoddy remanufacturing (especially if someone drilled into the battery to replace a single cell - as EV Clinic shows in their videos), that's why there are additional safeties with regards to bad isolation. So I stand by both takes.

ricardobeat 10mo ago

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