4 ms·

If there is anything that requires consumer protection its the batteries in these cars. The interface should not be proprietary. There should be no reason why y

If there is anything that requires consumer protection its the batteries in these cars. The interface should not be proprietary. There should be no reason why you couldn't buy $7000 worth of batteries, put them together with BMS systems, and replace them yourself.

mr337 3y ago
The only thing I can think of is the high voltage. I don't mind working with 220v but anything higher I tend to shy away with. I think some of the voltage systems in the battery packs can peak at 800v with most of them between 400v and 600v.
- beachy 3y ago
  The EV is also DC, significantly more dangerous than the AC at the same voltage.
  - Glawen 3y ago
    Well, no, AC is more lethal, also it contracts the muscles more easily. The high voltage ranges are different between AC and DC, with AC being lower than DC range due to the higher risk.
    - aitchnyu 3y ago
      Even in college, I was taught AC passes on your skin away from your heart and is therefore safer at the same voltage. Is this a myth?
      - petre 3y ago
        It's complicated and likely not at all relevant at 50 or 60 Hz frequencies. You want the sqrt(2p/ωμ) formula if you're curious. https://en.wikipedia.org/wiki/Skin_effect https://en.wikipedia.org/wiki/Skin_effect
    - beachy 3y ago
      My understanding is that DC currents are more dangerous as the effect is continuous. Whereas there is some electrician humour that at least with AC you have 50 chances per second to pull away (Americans get 60 chances per second)
      - junon 3y ago
        It's not so straightforward. Volts, amps, and frequency (in the case of AC) all play a factor in lethality of electricity.
    - SomeoneFromCA 3y ago
      keep in mind that peak voltage of AC is 1.4 of nominal. So keeping hat in mind, range is about same.
    - ericbarrett 3y ago
      I've been shocked by 300V DC @ 500mA and I'll take the equivalent AC any day. Obviously both can kill you, but the DC was far more painful and instantly gave me 3rd degree burns. Also made me ululate some kind of tone I didn't even know the human throat could emit.
      - natpalmer1776 3y ago
        The consensus I've heard from a few family members who work in airport maintenance is that HVDC will make you wish you were dead, while HVAC will make you dead dead.
- ActorNightly 3y ago
  The voltages are not going to be high enough to cause things like arcing through air. Basic precaution is necessary. The idea is not even that you yourself are going to replace it, its more for shops with equipment and skills to order individual cells, put together battery packs, and then just replace them in cars without worrying about compatibility.
pornel 3y ago
I think in many cases you can. If you replace with compatible cells, you can keep the BMS. For some batteries there are reverse-engineered or alternative BMSes. However, cells need careful soldering, and the BMS must be working properly to prevent overcharging and overheating. Mistakes can cause nasty and expensive fires, so it's not a DIY job for anybody.
- Tostino 3y ago
  Batteries need spot welding, not soldering. It is stupidly easy to use a spot welder to put together a pack without damaging the cells compared to soldering without damaging.
Kirby64 3y ago
You generally can. The problem is that the batteries are generally so specific to the car, you can't just swap them out with any random battery and expect the same performance. Additionally, given the immense power most battery packs put out, replacing individual cells (or banks) of batteries can cause an imbalance that will damage or degrade the pack over time. The best solution most of the time is to replace the entire pack at once if there's damage to a bank, and have the installer take the rest of your battery as a core rebate.
- PM_me_your_math 3y ago
  [dead]
rad_gruchalski 3y ago
But, but... we want structural batteries. I heard.

mr337 3y ago

The only thing I can think of is the high voltage. I don't mind working with 220v but anything higher I tend to shy away with. I think some of the voltage systems in the battery packs can peak at 800v with most of them between 400v and 600v.

beachy 3y ago
The EV is also DC, significantly more dangerous than the AC at the same voltage.
- Glawen 3y ago
  Well, no, AC is more lethal, also it contracts the muscles more easily. The high voltage ranges are different between AC and DC, with AC being lower than DC range due to the higher risk.
  - aitchnyu 3y ago
    Even in college, I was taught AC passes on your skin away from your heart and is therefore safer at the same voltage. Is this a myth?
    - petre 3y ago
      It's complicated and likely not at all relevant at 50 or 60 Hz frequencies. You want the sqrt(2p/ωμ) formula if you're curious. https://en.wikipedia.org/wiki/Skin_effect https://en.wikipedia.org/wiki/Skin_effect
  - beachy 3y ago
    My understanding is that DC currents are more dangerous as the effect is continuous. Whereas there is some electrician humour that at least with AC you have 50 chances per second to pull away (Americans get 60 chances per second)
    - junon 3y ago
      It's not so straightforward. Volts, amps, and frequency (in the case of AC) all play a factor in lethality of electricity.
  - SomeoneFromCA 3y ago
    keep in mind that peak voltage of AC is 1.4 of nominal. So keeping hat in mind, range is about same.
  - ericbarrett 3y ago
    I've been shocked by 300V DC @ 500mA and I'll take the equivalent AC any day. Obviously both can kill you, but the DC was far more painful and instantly gave me 3rd degree burns. Also made me ululate some kind of tone I didn't even know the human throat could emit.
    - natpalmer1776 3y ago
      The consensus I've heard from a few family members who work in airport maintenance is that HVDC will make you wish you were dead, while HVAC will make you dead dead.
ActorNightly 3y ago
The voltages are not going to be high enough to cause things like arcing through air. Basic precaution is necessary. The idea is not even that you yourself are going to replace it, its more for shops with equipment and skills to order individual cells, put together battery packs, and then just replace them in cars without worrying about compatibility.

pornel 3y ago

I think in many cases you can. If you replace with compatible cells, you can keep the BMS. For some batteries there are reverse-engineered or alternative BMSes. However, cells need careful soldering, and the BMS must be working properly to prevent overcharging and overheating. Mistakes can cause nasty and expensive fires, so it's not a DIY job for anybody.

Tostino 3y ago
Batteries need spot welding, not soldering. It is stupidly easy to use a spot welder to put together a pack without damaging the cells compared to soldering without damaging.

Kirby64 3y ago

You generally can. The problem is that the batteries are generally so specific to the car, you can't just swap them out with any random battery and expect the same performance. Additionally, given the immense power most battery packs put out, replacing individual cells (or banks) of batteries can cause an imbalance that will damage or degrade the pack over time. The best solution most of the time is to replace the entire pack at once if there's damage to a bank, and have the installer take the rest of your battery as a core rebate.

PM_me_your_math 3y ago
[dead]

rad_gruchalski 3y ago

But, but... we want structural batteries. I heard.