5 ms·

The cars shape and structural components are designed around the battery. The cars software, motors, charging electronics, software, cooling systems, etc are al

by gpm 5y ago

The cars shape and structural components are designed around the battery. The cars software, motors, charging electronics, software, cooling systems, etc are all designed for the specific battery. The battery eats up a significant fraction of the cost of the car, and the systems designed around it a significant fraction of the remainder. Asking for interoperable batteries between vehicle brands is like asking for interoperable engines between vehicle brands, it's ridiculous. The government should not be saying "hey, that $xx,xxxx item with a million constrains and optimizable variables, why don't you make it meet this arbitrary standard so people could theoretically put it in another chassis that wasn't designed to let you optimize it as well as possible".

SamBam 5y ago
Certainly no one should expect to be able to swap the main batteries that are embedded into the chassis of the car. The total weight of the batteries in a Tesla are around 1200 lbs. But it seems like there could be a hot-swappable portion of the battery, kind of like a separate "reserve tank" (although it wouldn't actually be reserved). Some back of the envelope math says that if 1200 lb battery gets you 250 miles, a 200 lb hot-swap battery would get you 40 miles. Possibly enough to get to your next destination.
- usefulcat 5y ago
  > a 200 lb hot-swap battery would get you 40 miles. According to one report, for a Tesla Model 3, a supercharger can add ~100 miles of range in ~10 minutes. It's hard to see how any improvement over that could possibly justify the immense additional complexity of physical battery swapping for only 40 additional miles of range. https://insideevs.com/news/506520/tesla-model-3-supercharger-test/ https://insideevs.com/news/506520/tesla-model-3-supercharger...
  - TeMPOraL 5y ago
    Does the Supercharger network come with a fleet of drones that can autonomously repair a charger in the middle of nowhere, that broke down one late evening of a particularly snowy winter Sunday? That said, it's probably a UX problem. Once EVs stop competing on range so much, it'll make sense to just designate the last 10% of battery as "reserve" and not count it in the battery level indicator.
    - nickik 5y ago
      No but there are always multiple supercharges at each station. > it'll make sense to just designate the last 10% of battery as "reserve" and not count it in the battery level indicator. Very questionable? Why would you do that? We don't do that for gas cars either.
      - bananasbandanas 5y ago
        Every ICE car I've ever driven did exactly that with the 'reserve' where the needle is already at (or below) the zero line but you still get about 50 km of range.
        TeMPOraL 5y ago
        Yup, exactly that. I think the use cases for field-swapping a (part of the) battery pack are the same as for carrying extra fuel canisters with you, which I can only speculate about, because I've never been in such situation with an ICE car.
        SamBam 5y ago
        I've been wondering about that with the cars with digital displays, particularly the ones that report your estimated remaining miles. I once, embarrassingly, found myself on the highway with an empty tank of gas and 20 miles to the next gas station. I watched the estimated miles remaining indicator tick down mile after mile, ticking precisely my passage. At 3 miles estimated remaining, I pulled over because there was a very wide safe shoulder, and I didn't want to putter out in a less-safe spot. I don't want to try the experiment of letting it tick down to zero and seeing if I still have 10 miles or so left.
    - usefulcat 5y ago
      I thought we were comparing fast charging to battery swapping. Surely a machine that physically swaps out a battery is going to be significantly larger and more complex than a supercharger, and therefore also much more likely to break down..
    - WorldMaker 5y ago
- vbezhenar 5y ago
  What about small generator and a canister of gasoline?
  - robin_reala 5y ago
    That’s what BMW did with their i3 REX models: a scooter engine and a tiny tank, hooked up to the electrical system. Turns out though that the extra weight impacted the performance without adding much in the way of range to the point that it wasn’t really worth it.
  - rapjr9 5y ago
    A 2000W inverter generator could give a Chevy Bolt an extra 14 miles of range after 3 hours of charging. A 240V generator could shorten that time or lengthen the range but would also be larger and take up more room in the car. Carrying gasoline in the back of your car all the time in case you run out of battery is somewhat dangerous. The generator means less cargo space as well. For a long trip to the middle of nowhere it may make sense to carry a generator and some gas. For a trip into town it may not.
beamatronic 5y ago
It's not ridiculous but it does lead to this conclusion: That there is probably a single optimal "skateboard" type design. Manufacturers are converging on this anyway. https://en.wikipedia.org/wiki/Skateboard_(automotive_platform) https://en.wikipedia.org/wiki/Skateboard_(automotive_platfor... Then the real truth that no one wants to hear, is that there is no need for so many different types of passenger vehicles.
- awesomeusername 5y ago
  It's astonishing how similar all cars are becoming, outside of the superficial stuff. For a reason. Convergence on the optimal solution.
  - hoseja 5y ago
    They are also optimizing for superficial appeal to customer, not 100% functionality.
  - dzhiurgis 5y ago
    If that’s actually true there will be one player to rule them all. Tesla essentially been selling same car for a decade.
- nickik 5y ago
  This is nonsense. That's like saying 'everybody converging on a 4 wheel design'. The details of how the platform is built and integrated is still very different. > Then the real truth that no one wants to hear, is that there is no need for so many different types of passenger vehicles. Good that we have you to tell us what vehicles people should drive.
lelanthran 5y ago
> Asking for interoperable batteries between vehicle brands is like asking for interoperable engines between vehicle brands, it's ridiculous. Engines are interoperable to a large degree; you can switch out the engine+ecu of your car for the engine+ecu of another car more easily than you'd think because the majority of the effort will be in changes requiring an adapter plate and shaft for the transmission. There are hurdles that make it harder (for example, auto transmissions have software that expects a particular set of engine characteristics), but by and large most engines are isolated enough from the rest of the car and the drivetrain that you don't need to worry.
- bratcomplex 5y ago
  Batteries are to the same degree. if you really wanted to, you could take a bunch of liquid cooled Tesla modules and fit them in a old leaf, when it’s batteries degrade.
BrandoElFollito 5y ago
> Asking for interoperable batteries between vehicle brands is like asking for interoperable engines between vehicle brands, it's ridiculous No, it is like asking batteries for radios follow the norm (so that they can be swapped), or petrol to be the same for all cars, with the same pouring mechanism (a round hole), or USB connectors to be the same between devices.
- tromp 5y ago
  Swappable batteries preclude the large weight savings of a structural battery that is an integral part of the car's chassis.
White_Wolf 5y ago
I'd say it should be possible to have a certain degree of compatibility just like I expect my GPU to work on any of the MB on the market supporting PCI-e(Space and cooling issues asside). The battery should be just a battery with a protection system. Charging and BMS should be separate and replaceable along with the battery. The OS of the car should support x number of BMS systems with a unified protocol. You want a Li-Ion pack? This BMS and this shielding are required. You want Lead batteries? This BMS needs to charge it. Do you want that new battery tech? You need the new BMS for it and an OS driver for the BMS. Plug it in and it's done.

by gpm 5y ago

SamBam 5y ago

Certainly no one should expect to be able to swap the main batteries that are embedded into the chassis of the car. The total weight of the batteries in a Tesla are around 1200 lbs. But it seems like there could be a hot-swappable portion of the battery, kind of like a separate "reserve tank" (although it wouldn't actually be reserved). Some back of the envelope math says that if 1200 lb battery gets you 250 miles, a 200 lb hot-swap battery would get you 40 miles. Possibly enough to get to your next destination.

usefulcat 5y ago
> a 200 lb hot-swap battery would get you 40 miles. According to one report, for a Tesla Model 3, a supercharger can add ~100 miles of range in ~10 minutes. It's hard to see how any improvement over that could possibly justify the immense additional complexity of physical battery swapping for only 40 additional miles of range. https://insideevs.com/news/506520/tesla-model-3-supercharger-test/ https://insideevs.com/news/506520/tesla-model-3-supercharger...
- TeMPOraL 5y ago
  Does the Supercharger network come with a fleet of drones that can autonomously repair a charger in the middle of nowhere, that broke down one late evening of a particularly snowy winter Sunday? That said, it's probably a UX problem. Once EVs stop competing on range so much, it'll make sense to just designate the last 10% of battery as "reserve" and not count it in the battery level indicator.
  - nickik 5y ago
    No but there are always multiple supercharges at each station. > it'll make sense to just designate the last 10% of battery as "reserve" and not count it in the battery level indicator. Very questionable? Why would you do that? We don't do that for gas cars either.
    - bananasbandanas 5y ago
      Every ICE car I've ever driven did exactly that with the 'reserve' where the needle is already at (or below) the zero line but you still get about 50 km of range.
      - TeMPOraL 5y ago
        Yup, exactly that. I think the use cases for field-swapping a (part of the) battery pack are the same as for carrying extra fuel canisters with you, which I can only speculate about, because I've never been in such situation with an ICE car.
      - SamBam 5y ago
        I've been wondering about that with the cars with digital displays, particularly the ones that report your estimated remaining miles. I once, embarrassingly, found myself on the highway with an empty tank of gas and 20 miles to the next gas station. I watched the estimated miles remaining indicator tick down mile after mile, ticking precisely my passage. At 3 miles estimated remaining, I pulled over because there was a very wide safe shoulder, and I didn't want to putter out in a less-safe spot. I don't want to try the experiment of letting it tick down to zero and seeing if I still have 10 miles or so left.
  - usefulcat 5y ago
    I thought we were comparing fast charging to battery swapping. Surely a machine that physically swaps out a battery is going to be significantly larger and more complex than a supercharger, and therefore also much more likely to break down..
  - WorldMaker 5y ago
vbezhenar 5y ago
What about small generator and a canister of gasoline?
- robin_reala 5y ago
  That’s what BMW did with their i3 REX models: a scooter engine and a tiny tank, hooked up to the electrical system. Turns out though that the extra weight impacted the performance without adding much in the way of range to the point that it wasn’t really worth it.
- rapjr9 5y ago
  A 2000W inverter generator could give a Chevy Bolt an extra 14 miles of range after 3 hours of charging. A 240V generator could shorten that time or lengthen the range but would also be larger and take up more room in the car. Carrying gasoline in the back of your car all the time in case you run out of battery is somewhat dangerous. The generator means less cargo space as well. For a long trip to the middle of nowhere it may make sense to carry a generator and some gas. For a trip into town it may not.

beamatronic 5y ago

It's not ridiculous but it does lead to this conclusion: That there is probably a single optimal "skateboard" type design. Manufacturers are converging on this anyway. https://en.wikipedia.org/wiki/Skateboard_(automotive_platform) https://en.wikipedia.org/wiki/Skateboard_(automotive_platfor... Then the real truth that no one wants to hear, is that there is no need for so many different types of passenger vehicles.

awesomeusername 5y ago
It's astonishing how similar all cars are becoming, outside of the superficial stuff. For a reason. Convergence on the optimal solution.
- hoseja 5y ago
  They are also optimizing for superficial appeal to customer, not 100% functionality.
- dzhiurgis 5y ago
  If that’s actually true there will be one player to rule them all. Tesla essentially been selling same car for a decade.
nickik 5y ago
This is nonsense. That's like saying 'everybody converging on a 4 wheel design'. The details of how the platform is built and integrated is still very different. > Then the real truth that no one wants to hear, is that there is no need for so many different types of passenger vehicles. Good that we have you to tell us what vehicles people should drive.

lelanthran 5y ago

> Asking for interoperable batteries between vehicle brands is like asking for interoperable engines between vehicle brands, it's ridiculous. Engines are interoperable to a large degree; you can switch out the engine+ecu of your car for the engine+ecu of another car more easily than you'd think because the majority of the effort will be in changes requiring an adapter plate and shaft for the transmission. There are hurdles that make it harder (for example, auto transmissions have software that expects a particular set of engine characteristics), but by and large most engines are isolated enough from the rest of the car and the drivetrain that you don't need to worry.

bratcomplex 5y ago
Batteries are to the same degree. if you really wanted to, you could take a bunch of liquid cooled Tesla modules and fit them in a old leaf, when it’s batteries degrade.

BrandoElFollito 5y ago

> Asking for interoperable batteries between vehicle brands is like asking for interoperable engines between vehicle brands, it's ridiculous No, it is like asking batteries for radios follow the norm (so that they can be swapped), or petrol to be the same for all cars, with the same pouring mechanism (a round hole), or USB connectors to be the same between devices.

tromp 5y ago
Swappable batteries preclude the large weight savings of a structural battery that is an integral part of the car's chassis.

White_Wolf 5y ago

I'd say it should be possible to have a certain degree of compatibility just like I expect my GPU to work on any of the MB on the market supporting PCI-e(Space and cooling issues asside). The battery should be just a battery with a protection system. Charging and BMS should be separate and replaceable along with the battery. The OS of the car should support x number of BMS systems with a unified protocol. You want a Li-Ion pack? This BMS and this shielding are required. You want Lead batteries? This BMS needs to charge it. Do you want that new battery tech? You need the new BMS for it and an OS driver for the BMS. Plug it in and it's done.