7 ms·

"Hackers" historically developed such a depth of understanding of some system that it allowed them to modify and subvert the system to suit their needs. The peo

"Hackers" historically developed such a depth of understanding of some system that it allowed them to modify and subvert the system to suit their needs. The people here who have built power systems for Battlebots and are familiar with the variability in specifications for 18650 cells and are saying that this isn't a good idea for reason X, Y, and Z, those people are the hackers. The people that are saying, "a battery's a battery, I'll just put it in a shed" are dabblers. They don't understand the technology well enough to do it safely, so they just build it with the assumption that it's going to go FOOF someday.

FussyZeus 9y ago
Well, the Powerwall, along with batteries, also has a ton of safety features that make it safe to install inside a home without worry. One would argue even if you know exactly what you're doing, unless you're replicating those same safety features as well, you should put it in a shed anyway. That said, totally agree with what you're saying.
- kbenson 9y ago
  > Well, the Powerwall, along with batteries, also has a ton of safety features that make it safe to install inside a home without worry. The logical conclusion of this is someone mentioning ICE vehicles and gas tanks, so allow me to be that person. If you park your gar in the garage and it's an ICE vehicle, you're parking quite a lot of latent energy in a fairly volatile form in your house. If you wouldn't feel comfortable rigging a bunch of old gas cans in tandem to a little engine your scrounged as a DIY generator and putting it in your garage, maybe you shouldn't rig a bunch of batteries up in a similar arrangement. For that matter, with that perspective, how far away for your cinderblock outhouse is far enough?
  - littlestymaar 9y ago
    The amount of energy isn't the most interesting thing to consider: a stack of logs contains way more energy than such a powerwall. What matters is “how stable” is that energy storage, and batteries are way less stable than wood ;)
    - kbenson 9y ago
      Well, yes, and that's what I said "in a fairly volatile form" with regard to gasoline. :) Any energy storage medium that holds a good amount of energy and has a methods to release it in a fairly short time frame (either through a failure mode or through intended use) deserves some real thought. Which is basically what you were saying...
      - FussyZeus 9y ago
        And I think that's why you don't see that kind of energy storage happen in a home very often. - Natural Gas is brought in through VERY small pipes, and is never kept anywhere, it's just used immediately. - Jerry cans are found regularly but are also sealed up as much as possible while still remaining usable. - Vehicles have sealed fuel systems, and are designed to not allow the fuel to combust all at once if at all possible. In fact, now that I'm thinking about it, pretty much the only time you hear about homes exploding/bursting into flame/etc. is when one or more of these systems is compromised.
        dragonwriter 9y ago
        > In fact, now that I'm thinking about it, pretty much the only time you hear about homes exploding/bursting into flame/etc. is when one or more of these systems is compromised. Medical oxygen plus ignition sources (especially cigarettes) seems to be another (for “bursting into flames” more than “exploding”.)
  - kwhitefoot 9y ago
    Where I live, Norway, if your garage is part of your house then it has to a have a firewall between it and the rest of the house.
    - kbenson 9y ago
      The same is often required in America. Garage doors usually need to be solid as well. That said, a firewall is not a fire proof wall, it's a wall designed to burn slower to prevent the fire spreading between those areas too quickly. Its purpose is to retard the fire u til it can be put out or so you have enough time to escape with your life. I suspect with failed batteries the latter is more likely your best chance.
rickbike 9y ago
"FOOF" is an interesting word choice. Have you heard of dioxygen difluoride, aka FOOF? If not, you may find this article interesting: http://blogs.sciencemag.org/pipeline/archives/2010/02/23/things_i_wont_work_with_dioxygen_difluoride http://blogs.sciencemag.org/pipeline/archives/2010/02/23/thi...
- thaumaturgy 9y ago
  I did in fact borrow it from that blog. That's probably my favorite chemistry-related "dessert reading". :-)
jsight 9y ago
You've created quite the false choice there. You've completely left out the people who know that it is in idea for reasons, X, Y, and Z (and maybe some others too) but are doing in anyway with a full understanding of how to modify and subvert those risks. You know, hacking with a depth of understanding. I think you are responding to a person like this.
amphibian87 9y ago
A battery is a battery, any lithium battery from a drill to a tesla is simply a 1.5 volt cylindrical cell stacked in series to produce the desired Voltage, then these stacks are connected in parallel or series again as needed (depends on application) to increase the load it can handle (Amperage). The safety features you're so worried about are just fuses. And maybe some diodes if you're that worried. I can say that installing a bank on a piece of plywood on your garage wall is obviously stupid, but a simple opening of the NEC book will show the code for a battery bank, shall have clearance from a wall and rest on non-flammable/non-conductive material, usually in a nuclear power plant or a substation we would build a rack out of metal then install ABS plastic shields. Source: I'm an industrial electrician and went through an IBEW apprenticeship,
- mrtimo 9y ago
  Honest question, I thought they were 3.6 volt cells?
  - zootboy 9y ago
    Depends on the chemistry. Normal li-ion chemistry is nominal 3.7V, max 4.2V. LiFePO4 chemistry is nominal 3.3V, max 3.6V. Plus there are other variants that have different parameters. I'm not aware of any lithium-based cell that has a nominal voltage of 1.5V, the commenter was probably thinking of alkaline cells.
- vvanders 9y ago
  Nope, different lithium batteries have different chemistry compositions. A LiFePO4 will happily catch on fire if you charge it with the same voltage/current curve as a LiPo(3.6v vs 4.2v). [edit] To expand a bit, this[1] is a fantastic reference on exactly how complicated and involved the different chemistries can be. This is talking about Lead -> LiFePo4 but a lot of stuff applies to LiPo and other variants as well. [1] https://marinehowto.com/lifepo4-batteries-on-boats/ https://marinehowto.com/lifepo4-batteries-on-boats/
  - snovv_crash 9y ago
metamet 9y ago
Since you mentioned Battlebots, I wanted to mention that when I was on Battlebots in 2002, the options for batteries were pretty damn slim. The was one company making a good product called Battlepacks (for lightweight - super heavyweight classes). If you were doing anything in the smaller weight classes (antweights through the 30lbers), you were typically hijacking a lot of remote aviation resources. The options available now are much better than they used to be.
tomxor 9y ago
> They don't understand the technology well enough to do it safely, so they just build it with the assumption that it's going to go FOOF someday. Accommodating for failure modes is not lack of understanding... most chemical batteries have some inherent combustive or explosive danger, lead acid can produce hydrogen explosions, LiPo can slow burn when the layers are punctured through expansion etc. Failure in a car is one thing (make sure it doesn't happen violently so that it can be controlled and escape is possible), but in a house you just can't afford for it to happen at all, sticking it in a separate building is a very reasonable and simple precaution for such a large quantity of chemical batteries on one place. It's bad enough when small laptop batteries burn up, and those have to pass safety test... imagine a few crates... in your house... under high load from having to power all of your appliances.
oreo81 9y ago
>"Hackers" historically developed such a depth of understanding of some system that it allowed them to modify and subvert the system to suit their needs. This is wrong on many levels. What you're describing is a scientist.
dopamean 9y ago
This definition of a hacker doesn't sit well with me. When I was a kid I hacked on things I didn't understand for a long time in order to get a better understanding. Was I not hacking? What I not a hacker then? I've never really put too much thought into it but always assumed I was.
- yock 9y ago
  Who cares? It's all just gatekeeping. Keep doing what you enjoy doing and don't worry about what categories other people put you in.
- walshemj 9y ago
  Trouble is that DC power at the levels required to be used as a replacement for mains is quite different to low voltage dc 5 /3.3v as say used by hackers who use ardunios etc. Talk to any telecoms vet and they will have stories about accidents with DC power hopefully funny ones not tragic ones
  - Dylan16807 9y ago
    Can you reference any stories? I can't find much. But the implication that you need to use high voltages isn't true. You can easily feed 24/36/48 volts into an inverter. The high current potential only acts weirdly when you short it out, which is where a couple fuses can prevent issues.
    - walshemj 9y ago
      Doesn't normaly make the news One of they ones I heard was about a painter who when painting the walls of a small exchange put the paint can across the bus bars which shorted and exploded the can of paint.
- cc439 9y ago
  There's a difference between "not fully understanding the functioning principles" of something and "not understanding what is potentially lethal about the functioning principles" of something. I messed around with plenty of things I barely understood as a kid but I knew where to draw the line when it came to messing around with things I didn't fully understand. I knew to hold off and do my research (basically, ask a competent adult) before messing around with anything to do with flammable and/or "powerful" chemicals (think heavy duty, old school brake dust cleaner from my grandfathers garage), electricity (this saved me from electrocuting myself with the capacitors in a CRT TV), and high temperatures. There are certain things that will make sense to someone with a pretty extensive knowledge of the subject at hand but are still in the category where the factors at play should make one pause and consult a professional. One example would be people who hook up generators to their 220V dryer connection in order to power their house in an emergency (it's called backfeeding). Technically, that should work but if you don't think to throw the main you'll wind up injuring or killing the lineman expecting a deenergized line when they come to restore power to your neighborhood.
lumberjack 9y ago
Personally I have no expertise on the matter, but there are also other hackers who have been doing this for ages. Go to EVTV.me, a community about home built EVs, for example. You'll find plenty of documented projects of recycling laptop cells for both EVs and home energy storage.
johnhenry 9y ago
From these comments, it seems like a "hacker" is either someone who understands the technology extremely well or not well at all... either way it's going to be fun ;) (and hopefully not too dangerous).

FussyZeus 9y ago

Well, the Powerwall, along with batteries, also has a ton of safety features that make it safe to install inside a home without worry. One would argue even if you know exactly what you're doing, unless you're replicating those same safety features as well, you should put it in a shed anyway. That said, totally agree with what you're saying.

kbenson 9y ago
> Well, the Powerwall, along with batteries, also has a ton of safety features that make it safe to install inside a home without worry. The logical conclusion of this is someone mentioning ICE vehicles and gas tanks, so allow me to be that person. If you park your gar in the garage and it's an ICE vehicle, you're parking quite a lot of latent energy in a fairly volatile form in your house. If you wouldn't feel comfortable rigging a bunch of old gas cans in tandem to a little engine your scrounged as a DIY generator and putting it in your garage, maybe you shouldn't rig a bunch of batteries up in a similar arrangement. For that matter, with that perspective, how far away for your cinderblock outhouse is far enough?
- littlestymaar 9y ago
  The amount of energy isn't the most interesting thing to consider: a stack of logs contains way more energy than such a powerwall. What matters is “how stable” is that energy storage, and batteries are way less stable than wood ;)
  - kbenson 9y ago
    Well, yes, and that's what I said "in a fairly volatile form" with regard to gasoline. :) Any energy storage medium that holds a good amount of energy and has a methods to release it in a fairly short time frame (either through a failure mode or through intended use) deserves some real thought. Which is basically what you were saying...
    - FussyZeus 9y ago
      And I think that's why you don't see that kind of energy storage happen in a home very often. - Natural Gas is brought in through VERY small pipes, and is never kept anywhere, it's just used immediately. - Jerry cans are found regularly but are also sealed up as much as possible while still remaining usable. - Vehicles have sealed fuel systems, and are designed to not allow the fuel to combust all at once if at all possible. In fact, now that I'm thinking about it, pretty much the only time you hear about homes exploding/bursting into flame/etc. is when one or more of these systems is compromised.
      - dragonwriter 9y ago
        > In fact, now that I'm thinking about it, pretty much the only time you hear about homes exploding/bursting into flame/etc. is when one or more of these systems is compromised. Medical oxygen plus ignition sources (especially cigarettes) seems to be another (for “bursting into flames” more than “exploding”.)
- kwhitefoot 9y ago
  Where I live, Norway, if your garage is part of your house then it has to a have a firewall between it and the rest of the house.
  - kbenson 9y ago
    The same is often required in America. Garage doors usually need to be solid as well. That said, a firewall is not a fire proof wall, it's a wall designed to burn slower to prevent the fire spreading between those areas too quickly. Its purpose is to retard the fire u til it can be put out or so you have enough time to escape with your life. I suspect with failed batteries the latter is more likely your best chance.

rickbike 9y ago

"FOOF" is an interesting word choice. Have you heard of dioxygen difluoride, aka FOOF? If not, you may find this article interesting: http://blogs.sciencemag.org/pipeline/archives/2010/02/23/things_i_wont_work_with_dioxygen_difluoride http://blogs.sciencemag.org/pipeline/archives/2010/02/23/thi...

thaumaturgy 9y ago
I did in fact borrow it from that blog. That's probably my favorite chemistry-related "dessert reading". :-)

jsight 9y ago

You've created quite the false choice there. You've completely left out the people who know that it is in idea for reasons, X, Y, and Z (and maybe some others too) but are doing in anyway with a full understanding of how to modify and subvert those risks. You know, hacking with a depth of understanding. I think you are responding to a person like this.

amphibian87 9y ago

A battery is a battery, any lithium battery from a drill to a tesla is simply a 1.5 volt cylindrical cell stacked in series to produce the desired Voltage, then these stacks are connected in parallel or series again as needed (depends on application) to increase the load it can handle (Amperage). The safety features you're so worried about are just fuses. And maybe some diodes if you're that worried. I can say that installing a bank on a piece of plywood on your garage wall is obviously stupid, but a simple opening of the NEC book will show the code for a battery bank, shall have clearance from a wall and rest on non-flammable/non-conductive material, usually in a nuclear power plant or a substation we would build a rack out of metal then install ABS plastic shields. Source: I'm an industrial electrician and went through an IBEW apprenticeship,

mrtimo 9y ago
Honest question, I thought they were 3.6 volt cells?
- zootboy 9y ago
  Depends on the chemistry. Normal li-ion chemistry is nominal 3.7V, max 4.2V. LiFePO4 chemistry is nominal 3.3V, max 3.6V. Plus there are other variants that have different parameters. I'm not aware of any lithium-based cell that has a nominal voltage of 1.5V, the commenter was probably thinking of alkaline cells.
vvanders 9y ago
Nope, different lithium batteries have different chemistry compositions. A LiFePO4 will happily catch on fire if you charge it with the same voltage/current curve as a LiPo(3.6v vs 4.2v). [edit] To expand a bit, this[1] is a fantastic reference on exactly how complicated and involved the different chemistries can be. This is talking about Lead -> LiFePo4 but a lot of stuff applies to LiPo and other variants as well. [1] https://marinehowto.com/lifepo4-batteries-on-boats/ https://marinehowto.com/lifepo4-batteries-on-boats/
- snovv_crash 9y ago

metamet 9y ago

Since you mentioned Battlebots, I wanted to mention that when I was on Battlebots in 2002, the options for batteries were pretty damn slim. The was one company making a good product called Battlepacks (for lightweight - super heavyweight classes). If you were doing anything in the smaller weight classes (antweights through the 30lbers), you were typically hijacking a lot of remote aviation resources. The options available now are much better than they used to be.

tomxor 9y ago

> They don't understand the technology well enough to do it safely, so they just build it with the assumption that it's going to go FOOF someday. Accommodating for failure modes is not lack of understanding... most chemical batteries have some inherent combustive or explosive danger, lead acid can produce hydrogen explosions, LiPo can slow burn when the layers are punctured through expansion etc. Failure in a car is one thing (make sure it doesn't happen violently so that it can be controlled and escape is possible), but in a house you just can't afford for it to happen at all, sticking it in a separate building is a very reasonable and simple precaution for such a large quantity of chemical batteries on one place. It's bad enough when small laptop batteries burn up, and those have to pass safety test... imagine a few crates... in your house... under high load from having to power all of your appliances.

oreo81 9y ago

>"Hackers" historically developed such a depth of understanding of some system that it allowed them to modify and subvert the system to suit their needs. This is wrong on many levels. What you're describing is a scientist.

dopamean 9y ago

This definition of a hacker doesn't sit well with me. When I was a kid I hacked on things I didn't understand for a long time in order to get a better understanding. Was I not hacking? What I not a hacker then? I've never really put too much thought into it but always assumed I was.

yock 9y ago
Who cares? It's all just gatekeeping. Keep doing what you enjoy doing and don't worry about what categories other people put you in.
walshemj 9y ago
Trouble is that DC power at the levels required to be used as a replacement for mains is quite different to low voltage dc 5 /3.3v as say used by hackers who use ardunios etc. Talk to any telecoms vet and they will have stories about accidents with DC power hopefully funny ones not tragic ones
- Dylan16807 9y ago
  Can you reference any stories? I can't find much. But the implication that you need to use high voltages isn't true. You can easily feed 24/36/48 volts into an inverter. The high current potential only acts weirdly when you short it out, which is where a couple fuses can prevent issues.
  - walshemj 9y ago
    Doesn't normaly make the news One of they ones I heard was about a painter who when painting the walls of a small exchange put the paint can across the bus bars which shorted and exploded the can of paint.
cc439 9y ago
There's a difference between "not fully understanding the functioning principles" of something and "not understanding what is potentially lethal about the functioning principles" of something. I messed around with plenty of things I barely understood as a kid but I knew where to draw the line when it came to messing around with things I didn't fully understand. I knew to hold off and do my research (basically, ask a competent adult) before messing around with anything to do with flammable and/or "powerful" chemicals (think heavy duty, old school brake dust cleaner from my grandfathers garage), electricity (this saved me from electrocuting myself with the capacitors in a CRT TV), and high temperatures. There are certain things that will make sense to someone with a pretty extensive knowledge of the subject at hand but are still in the category where the factors at play should make one pause and consult a professional. One example would be people who hook up generators to their 220V dryer connection in order to power their house in an emergency (it's called backfeeding). Technically, that should work but if you don't think to throw the main you'll wind up injuring or killing the lineman expecting a deenergized line when they come to restore power to your neighborhood.

lumberjack 9y ago

Personally I have no expertise on the matter, but there are also other hackers who have been doing this for ages. Go to EVTV.me, a community about home built EVs, for example. You'll find plenty of documented projects of recycling laptop cells for both EVs and home energy storage.

johnhenry 9y ago

From these comments, it seems like a "hacker" is either someone who understands the technology extremely well or not well at all... either way it's going to be fun ;) (and hopefully not too dangerous).