Comment by Glawen
8 hours 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
8 hours 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
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.
Yikes, that sounds dangerous.
I'd personally prefer e.g. 48V even if that meant some more losses and/or thicker cables.
9 replies →
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.
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.
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.
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.