5 ms·

Then that’s more the issue with the BMS rather than the cells

by h0l0cube 2y ago

samatman 2y ago
Problems with the BMS can become problems with the cells very quickly.
- h0l0cube 2y ago
  Yeah, but I would just buy the cells and spend more on a BMS. Or you can just use a low voltage cutoff and an active balancer for a smaller setup
Aurornis 2y ago
In many of the systems, the BMS and battery are one in the same. This article blurs the lines between the cells and battery system, too.
- h0l0cube 2y ago
  The post you were replying to was specifically about cells, and if you’re going for economy, building your own packs are substantially cheaper than buying packs domestically. Also less fraught when you’ve DIYed to diagnose and fix when things go wrong
  - lazide 2y ago
    Also prone to average people setting themselves or their houses on fire, eh?
    - h0l0cube 2y ago
      Depends on how scrupulous Average Person is being. There's codes for electrical and solar installations that can be followed, and it's best to stick to the letter, even if you're certain it doesn't apply. And after that, you should get it certified by a licensed professional, but would also need a licensed professional to hook it up to the grid
      - lazide 2y ago
        I think you’re misunderstanding what I’m trying to say. I’m talking about assembling your own multi-kwh lithium battery assemblies (pre-BMS even). One wrong poke with a screwdriver, and all sorts of entertainment is likely to ensue eh? And they’re big enough, no portable fire extinguisher is going to make a dent either.
        defrost 2y ago
        Sure, you're saying some people shouldn't DIY. Where I live many people DIY as a great many people have mad skills (lots of FiFo workers making a good living from O&G installions and big mining projects). They build their own houses, their own planes, off grid power systems, water proof EV's to drive across harbour floors, etc. If you've got a big (shipping container sized) battery pack you need a big thermal blanket to cut off the oxygen or a wide enough fire break about it. Speaking of DIY home builds, here's a good use of black builders plastic: https://www.youtube.com/watch?v=1ILbQHnHPnY https://www.youtube.com/watch?v=1ILbQHnHPnY
        lazide 2y ago
        No, you’re talking about building structures. I’m talking about assembling a bomb. A 5kwh battery contains about 18MJ of energy, equivalent to 4.3KG of TNT. Short that out or puncture on of its component pouches, and it’s going to be very dramatic. One of them requires a different degree of care than the other.
        defrost 2y ago
        You're still making the same irresponsible and frankly silly generalisation about "average" people. Most people, full stop, don't build houses, metal work shops, treat their own sewerage, build their own power systems, etc. So "average" people just don't start fires or set off bombs because they're not doing anything that dangerous. Of the people that do, say, build their own glass furnaces, annealing ovens, laying out gas lines and installing small truck sized propane tanks with more energy than a 5kwh battery .. easily less than half, well below the "average" number of people that do such things, have accidents. Sure, some people do watch Forged in Fire and have a go at knife making in a home built furnace, and then set fire to their barn | house | shed. Most people don't try, and of those that do have a go most of them don't screw it up. The point being, this: > Also prone to average people setting themselves or their houses on fire, eh? is just silly. Average people don't attempt this, and of the people that do attempt such things most don't cock it up. Perhaps your personal experience differs. Maybe you can't dig your own septic system and fit it out without shit running back into your house.
  - oulipo 2y ago
    This is why at https://gouach.com https://gouach.com we've built the first easy-to-repair, easy-to-swap-cell battery! We're launching a Kickstarter soon, stay tuned (on our newsletter!)

Then that’s more the issue with the BMS rather than the cells

samatman 2y ago

Problems with the BMS can become problems with the cells very quickly.

h0l0cube 2y ago
Yeah, but I would just buy the cells and spend more on a BMS. Or you can just use a low voltage cutoff and an active balancer for a smaller setup

Aurornis 2y ago

In many of the systems, the BMS and battery are one in the same. This article blurs the lines between the cells and battery system, too.

h0l0cube 2y ago
The post you were replying to was specifically about cells, and if you’re going for economy, building your own packs are substantially cheaper than buying packs domestically. Also less fraught when you’ve DIYed to diagnose and fix when things go wrong
- lazide 2y ago
  Also prone to average people setting themselves or their houses on fire, eh?
  - h0l0cube 2y ago
    Depends on how scrupulous Average Person is being. There's codes for electrical and solar installations that can be followed, and it's best to stick to the letter, even if you're certain it doesn't apply. And after that, you should get it certified by a licensed professional, but would also need a licensed professional to hook it up to the grid
    - lazide 2y ago
      I think you’re misunderstanding what I’m trying to say. I’m talking about assembling your own multi-kwh lithium battery assemblies (pre-BMS even). One wrong poke with a screwdriver, and all sorts of entertainment is likely to ensue eh? And they’re big enough, no portable fire extinguisher is going to make a dent either.
      - defrost 2y ago
        Sure, you're saying some people shouldn't DIY. Where I live many people DIY as a great many people have mad skills (lots of FiFo workers making a good living from O&G installions and big mining projects). They build their own houses, their own planes, off grid power systems, water proof EV's to drive across harbour floors, etc. If you've got a big (shipping container sized) battery pack you need a big thermal blanket to cut off the oxygen or a wide enough fire break about it. Speaking of DIY home builds, here's a good use of black builders plastic: https://www.youtube.com/watch?v=1ILbQHnHPnY https://www.youtube.com/watch?v=1ILbQHnHPnY
        lazide 2y ago
        No, you’re talking about building structures. I’m talking about assembling a bomb. A 5kwh battery contains about 18MJ of energy, equivalent to 4.3KG of TNT. Short that out or puncture on of its component pouches, and it’s going to be very dramatic. One of them requires a different degree of care than the other.
        defrost 2y ago
        You're still making the same irresponsible and frankly silly generalisation about "average" people. Most people, full stop, don't build houses, metal work shops, treat their own sewerage, build their own power systems, etc. So "average" people just don't start fires or set off bombs because they're not doing anything that dangerous. Of the people that do, say, build their own glass furnaces, annealing ovens, laying out gas lines and installing small truck sized propane tanks with more energy than a 5kwh battery .. easily less than half, well below the "average" number of people that do such things, have accidents. Sure, some people do watch Forged in Fire and have a go at knife making in a home built furnace, and then set fire to their barn | house | shed. Most people don't try, and of those that do have a go most of them don't screw it up. The point being, this: > Also prone to average people setting themselves or their houses on fire, eh? is just silly. Average people don't attempt this, and of the people that do attempt such things most don't cock it up. Perhaps your personal experience differs. Maybe you can't dig your own septic system and fit it out without shit running back into your house.
- oulipo 2y ago
  This is why at https://gouach.com https://gouach.com we've built the first easy-to-repair, easy-to-swap-cell battery! We're launching a Kickstarter soon, stay tuned (on our newsletter!)