7 ms·

I used to think the same, but I'm starting to disagree. Batteries aren't as "fungible" as something like gas or electricity is. (is that the right word to use

I used to think the same, but I'm starting to disagree. Batteries aren't as "fungible" as something like gas or electricity is. (is that the right word to use for this?) You can be reasonably sure that gas is gas, and electricity is electricity, but not all batteries are going to be the same. Some will be higher capacity, some will have greater life, some will be heavier or lighter, some cars or trucks will need bigger or smaller batteries, etc... Some could even be damaged and unsafe, which is something you don't really get with gas (sure bad gas could ruin your car, but gas from a pump isn't going to catch fire randomly and hurt you because it's bad) At the end of the day, it's just too much variation for me to trust a random battery pulled from a depot of them. The thought experiment that put me over the edge was imagine instead of batteries, we were talking about tires. What if it was deemed better to swap out your tire when you had to put air in it. So you brought it to your shop and they pulled the wheel and tire off, then put one that they had in-store on full of air, and they refilled the one you gave them and handed it to someone else. Would you trust that? How would it change how we handle tires on cars? Would the public go for it? I really don't think they would, I know I wouldn't, and it's the same kind of feeling with car batteries.

throwaway5752 8y ago
You assume gasoline is fungible, right?
- Klathmon 8y ago
  to an extent that it matters, yeah. Sure, I put 87 octane in our SUV and 89 in the audi, but yeah for the most part gas is gas, unless something is wrong. Getting 2 random batteries to have less than 10% variance among them is going to be a lot harder (especially when battery health changes a lot depending on how they are treated. Users running them to near empty in cold weather is going to shorten the life a lot faster than the guy who only runs it to 50% before swapping out every time), and I have a feeling that the amount of "problem" batteries will be much higher than the amount of times i've ever had "problem gas" (which is basically 0 times so far).
  - throwaway5752 8y ago
    I am assuming in a hypothetical battery swap world batteries would be rigorously tested before replacement. How hard do you think it would be (sincerely)? For the gasoline analogy, there are lots of ways to achieve an octane rating but I suspect most people only use the "do I hear engine knock" test. Similarly, I would be fine of a guarantee of if I have 300 mi of electric range (whether it's 300, 310, or 320) under normal driving conditions for a battery swap, as a trade off for convenience.
    - Klathmon 8y ago
      I really think it would be a lot harder than testing gasoline. For starters, with gas and other things like it, there is a supply chain which is pretty tight. If one supplier starts giving bad gas, you can blacklist them and move on. With batteries you'd have to test them after every single use, because you don't know what the last user has done to them. Then they need to be physically inspected, because a puncture or deep gouge or crack or something could cause big issues. Then their actual capacity needs to be tested some how. I'll admit that I've been outside of the battery ecosystem for a while, but years ago it wasn't all that easy to "spot check" a random battery to find it's health and capacity. Most devices would gain that knowledge about a battery over a few charge cycles. You need to make sure you know it off the bat, and you can't be wrong or I'll lose faith in the company and the tech. Then throw in the complication of different sizes, different shapes, different technologies, different requirements (this isn't just the "gas" part of fuel, it's also the "gas tank", so one size will never fit all), and now you are maintaining huge banks of different kinds of batteries all while charging them to the right amount without degrading them, and checking that users didn't run them in below freezing to almost 0 percent which would reduce the lifetime and aren't damaging them in any way which would be very unsafe. In an ideal world, it sounds like a great idea, but I just don't trust that it can be pulled off without making the user's life worse than if they didn't do it.
      - throwaway5752 8y ago
        A couple of things: when I think about it, I implicitly think about it as a vendor specific thing. Like Tesla supercharger stations. Agree that battery standards across makers likely impossible. Second, I think the major upside is removing a large potential liability from each vehicle - as hybrid vehicles are entering "old used car" ages/mileages, all your points about assessing the health of the battery apply to 2ary buyers and ability for people to monetize their old vehicles. Bringing it back around to the topic, I don't know that we can wait on solid state and this represents a work around while smarter people that I can figure that out.
- spullara 8y ago
  If you investigate the way gasoline is distributed in the US you will see that it is extremely fungible.
  - throwaway5752 8y ago
    Sure, but my point is that you have gasoline being produced by many companies and production facilities, from many different/blended inputs (heavy oil with low gravity, NGLs, ethanol mixture, et al), and with proprietary additions. There's no reason that batteries can't be checked that the meet spec before they are replaced in your car in the same way.
    - jstarfish 8y ago
      I'd be surprised if each battery couldn't come with a little computer that tracks charge times, cycles and power output over time. It would make it trivial to monitor whether or not a battery is currently serviceable (or whether it will expire prematurely). For EV fleets we used to only be able to do this per vehicle (not by battery) while the vehicle was home and charging, by shipping the fleet battery metrics to a central aggregator. But that is overkill for consumer vehicles.
      - bradknowles 8y ago
        With Tesla, every single cell has a computer chip monitoring its performance on a variety of issues. And the aggregate data for that is all called back to HQ on a regular basis. Tesla knows better than you ever possibly could as to how well each and every cell in your battery packs is doing.
- Kadin 8y ago
  Gasoline is largely fungible because it's required by law to be. What can be called gasoline, what additives can (and are required to be) put into it, how much energy it has per liter, etc., are all regulated. There was a time where gasoline brands mattered, and the gas you got from Esso might have been slightly different than the gas from Sinclair or Hess or whatever, but that was intentionally regulated into irrelevance because the benefit to consumers of a consistent product was more valuable than allowing brands to differentiate themselves. It took several decades after the widespread adoption of the car (and gasoline as the dominant fuel) for this to happen, and during this time users had to struggle with varying fuels produced from different feedstocks, gumming of engines, dilution of crankcase oil, etc. (This is referred to in period motoring publications as "the Fuel Problem".) The automobile industries and the oil industries basically pointed fingers at each other until the US Bureau of Standards had to step in and mediate on a consistent set of standards that the refiners would produce fuel to, and the engine manufacturers would design their engines against. If this hadn't happened, and the market had been left to sort it out, I suspect you would have ended up having to fill your Ford car only at Sinclair stations, based on some Ford/Sinclair arrangement or whatever. Unfortunately the 'solution' to the Fuel Problem in the 30s involved the introduction of tetraethyl lead, which mars what would have been a good example of mutually beneficial public-private cooperation and useful regulation.
jsight 8y ago
I like your tire analogy. While it is probably true that the risks would be lower with battery swaps, it is also true that the marginal benefit isn't so great as people tend to perceive. Would you take the marginal risk of a battery swap (plus the costs of all those batteries in inventory throughout the country) in order to save 60 minutes on a 600 mile trip? And is the infrastructure to do all of that really less expensive than putting a charger at enough restaurants for you to just stop and eat while the car charges?
- Klathmon 8y ago
  >Would you take the marginal risk of a battery swap (plus the costs of all those batteries in inventory throughout the country) in order to save 60 minutes on a 600 mile trip? I honestly think I would for a trip like that. But at the same time I wouldn't want to be stuck with a potentially "sub-par" battery after that trip either. And those 2 things seem pretty at odds with one another. Like in a perfect world I'd love to be able to have it as an option, but I'm not willing to give up "my" battery in my current (hypothetical!) car for one of unknown quality. Perhaps a "booster" system would work then in this case? You don't swap out the actual battery in the car, but instead swap out batteries that go in your trunk or something and charge your actual battery while driving! Then you don't care about how shitty that pack is, you are only using it to "recharge" on the go!
  - qqqwerty 8y ago
    600 miles is equal to about 10 hours of driving (very roughly). There are very few people who would do that trip without stopping at least a few times (bathroom, food, stretch, etc...) and if charging infrastructure is common enough (which it will be) than a good chunk of those 60 minutes can be done in concert with those stops. And compared to ICE vehicles, most would need about 2 re-fueling stops to make that trip[1]. So an aggressive ICE trip would still result in about 10-20 minutes of re-fueling time. Another thing to consider, it is much more likely that we will see 400mi range electrics sooner and/or easier than we could roll out a large network of battery swap stations. I think the concept of battery swap is solid. Most batteries have BMS systems that prevent over/under charging and any physical damage can be detected. Plus the battery would likely be owned by a third party, so it would not be a big deal if you got stuck with a bad battery, you would just swap it out for another one. The main issue is logistics. Much harder to build a network of battery swap stations then it is to put some fast chargers in parking lots. And if we can get the range up to 400 miles, then a 600 mile trip could be done with 20-30 minutes of super charging. [1] Assuming a ~300 mile ICE range, you need to fill up at the start, at the middle, and at the end (although one could wait till the next morning, but I think it should still count). Whereas electric, you start full (because you plugged in overnight prior to departure), and you end full (assuming you can plug in overnight at your destination). These are rough assumptions, but I think 2 fuel stops is a good approximation, but many would need 3 (including my own ICE car, which gets ~250 miles per tank).

throwaway5752 8y ago

You assume gasoline is fungible, right?

Klathmon 8y ago
to an extent that it matters, yeah. Sure, I put 87 octane in our SUV and 89 in the audi, but yeah for the most part gas is gas, unless something is wrong. Getting 2 random batteries to have less than 10% variance among them is going to be a lot harder (especially when battery health changes a lot depending on how they are treated. Users running them to near empty in cold weather is going to shorten the life a lot faster than the guy who only runs it to 50% before swapping out every time), and I have a feeling that the amount of "problem" batteries will be much higher than the amount of times i've ever had "problem gas" (which is basically 0 times so far).
- throwaway5752 8y ago
  I am assuming in a hypothetical battery swap world batteries would be rigorously tested before replacement. How hard do you think it would be (sincerely)? For the gasoline analogy, there are lots of ways to achieve an octane rating but I suspect most people only use the "do I hear engine knock" test. Similarly, I would be fine of a guarantee of if I have 300 mi of electric range (whether it's 300, 310, or 320) under normal driving conditions for a battery swap, as a trade off for convenience.
  - Klathmon 8y ago
    I really think it would be a lot harder than testing gasoline. For starters, with gas and other things like it, there is a supply chain which is pretty tight. If one supplier starts giving bad gas, you can blacklist them and move on. With batteries you'd have to test them after every single use, because you don't know what the last user has done to them. Then they need to be physically inspected, because a puncture or deep gouge or crack or something could cause big issues. Then their actual capacity needs to be tested some how. I'll admit that I've been outside of the battery ecosystem for a while, but years ago it wasn't all that easy to "spot check" a random battery to find it's health and capacity. Most devices would gain that knowledge about a battery over a few charge cycles. You need to make sure you know it off the bat, and you can't be wrong or I'll lose faith in the company and the tech. Then throw in the complication of different sizes, different shapes, different technologies, different requirements (this isn't just the "gas" part of fuel, it's also the "gas tank", so one size will never fit all), and now you are maintaining huge banks of different kinds of batteries all while charging them to the right amount without degrading them, and checking that users didn't run them in below freezing to almost 0 percent which would reduce the lifetime and aren't damaging them in any way which would be very unsafe. In an ideal world, it sounds like a great idea, but I just don't trust that it can be pulled off without making the user's life worse than if they didn't do it.
    - throwaway5752 8y ago
      A couple of things: when I think about it, I implicitly think about it as a vendor specific thing. Like Tesla supercharger stations. Agree that battery standards across makers likely impossible. Second, I think the major upside is removing a large potential liability from each vehicle - as hybrid vehicles are entering "old used car" ages/mileages, all your points about assessing the health of the battery apply to 2ary buyers and ability for people to monetize their old vehicles. Bringing it back around to the topic, I don't know that we can wait on solid state and this represents a work around while smarter people that I can figure that out.
spullara 8y ago
If you investigate the way gasoline is distributed in the US you will see that it is extremely fungible.
- throwaway5752 8y ago
  Sure, but my point is that you have gasoline being produced by many companies and production facilities, from many different/blended inputs (heavy oil with low gravity, NGLs, ethanol mixture, et al), and with proprietary additions. There's no reason that batteries can't be checked that the meet spec before they are replaced in your car in the same way.
  - jstarfish 8y ago
    I'd be surprised if each battery couldn't come with a little computer that tracks charge times, cycles and power output over time. It would make it trivial to monitor whether or not a battery is currently serviceable (or whether it will expire prematurely). For EV fleets we used to only be able to do this per vehicle (not by battery) while the vehicle was home and charging, by shipping the fleet battery metrics to a central aggregator. But that is overkill for consumer vehicles.
    - bradknowles 8y ago
      With Tesla, every single cell has a computer chip monitoring its performance on a variety of issues. And the aggregate data for that is all called back to HQ on a regular basis. Tesla knows better than you ever possibly could as to how well each and every cell in your battery packs is doing.
Kadin 8y ago
Gasoline is largely fungible because it's required by law to be. What can be called gasoline, what additives can (and are required to be) put into it, how much energy it has per liter, etc., are all regulated. There was a time where gasoline brands mattered, and the gas you got from Esso might have been slightly different than the gas from Sinclair or Hess or whatever, but that was intentionally regulated into irrelevance because the benefit to consumers of a consistent product was more valuable than allowing brands to differentiate themselves. It took several decades after the widespread adoption of the car (and gasoline as the dominant fuel) for this to happen, and during this time users had to struggle with varying fuels produced from different feedstocks, gumming of engines, dilution of crankcase oil, etc. (This is referred to in period motoring publications as "the Fuel Problem".) The automobile industries and the oil industries basically pointed fingers at each other until the US Bureau of Standards had to step in and mediate on a consistent set of standards that the refiners would produce fuel to, and the engine manufacturers would design their engines against. If this hadn't happened, and the market had been left to sort it out, I suspect you would have ended up having to fill your Ford car only at Sinclair stations, based on some Ford/Sinclair arrangement or whatever. Unfortunately the 'solution' to the Fuel Problem in the 30s involved the introduction of tetraethyl lead, which mars what would have been a good example of mutually beneficial public-private cooperation and useful regulation.

jsight 8y ago

I like your tire analogy. While it is probably true that the risks would be lower with battery swaps, it is also true that the marginal benefit isn't so great as people tend to perceive. Would you take the marginal risk of a battery swap (plus the costs of all those batteries in inventory throughout the country) in order to save 60 minutes on a 600 mile trip? And is the infrastructure to do all of that really less expensive than putting a charger at enough restaurants for you to just stop and eat while the car charges?

Klathmon 8y ago
>Would you take the marginal risk of a battery swap (plus the costs of all those batteries in inventory throughout the country) in order to save 60 minutes on a 600 mile trip? I honestly think I would for a trip like that. But at the same time I wouldn't want to be stuck with a potentially "sub-par" battery after that trip either. And those 2 things seem pretty at odds with one another. Like in a perfect world I'd love to be able to have it as an option, but I'm not willing to give up "my" battery in my current (hypothetical!) car for one of unknown quality. Perhaps a "booster" system would work then in this case? You don't swap out the actual battery in the car, but instead swap out batteries that go in your trunk or something and charge your actual battery while driving! Then you don't care about how shitty that pack is, you are only using it to "recharge" on the go!
- qqqwerty 8y ago
  600 miles is equal to about 10 hours of driving (very roughly). There are very few people who would do that trip without stopping at least a few times (bathroom, food, stretch, etc...) and if charging infrastructure is common enough (which it will be) than a good chunk of those 60 minutes can be done in concert with those stops. And compared to ICE vehicles, most would need about 2 re-fueling stops to make that trip[1]. So an aggressive ICE trip would still result in about 10-20 minutes of re-fueling time. Another thing to consider, it is much more likely that we will see 400mi range electrics sooner and/or easier than we could roll out a large network of battery swap stations. I think the concept of battery swap is solid. Most batteries have BMS systems that prevent over/under charging and any physical damage can be detected. Plus the battery would likely be owned by a third party, so it would not be a big deal if you got stuck with a bad battery, you would just swap it out for another one. The main issue is logistics. Much harder to build a network of battery swap stations then it is to put some fast chargers in parking lots. And if we can get the range up to 400 miles, then a 600 mile trip could be done with 20-30 minutes of super charging. [1] Assuming a ~300 mile ICE range, you need to fill up at the start, at the middle, and at the end (although one could wait till the next morning, but I think it should still count). Whereas electric, you start full (because you plugged in overnight prior to departure), and you end full (assuming you can plug in overnight at your destination). These are rough assumptions, but I think 2 fuel stops is a good approximation, but many would need 3 (including my own ICE car, which gets ~250 miles per tank).