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Battery swaps could be viable, barring some complications in gate infrastructure and airframe design. Obviously this would be impossible if airframe designers i

Battery swaps could be viable, barring some complications in gate infrastructure and airframe design. Obviously this would be impossible if airframe designers incorporate battery cells in structural members, as some suggest to offset the weight penalty.

nielsbot 5y ago
The "more info" page on their website says they are ruling out battery swaps, at least for now, since a battery swap would require a mechanical certification every time it was done. They are swappable though: they explain that used battery packs can be replaced and that used packs can be used for a second purpose with less stringent requirements. For example, an energy storage facility at the airport.
hutzlibu 5y ago
"Obviously this would be impossible if airframe designers incorporate battery cells in structural members, as some suggest to offset the weight penalty." Why not do both? Swap one part and charge just the internal batteries. But internal batteries does not sound so clever with limited lifetime anyway.
- tgsovlerkhgsel 5y ago
  Charging is limited by two factors: - the power you can get from the charger to the batteries - the power the cells can accept You can reasonably easily fix the first point with custom infrastructure, so the second point will be the limiting factor, and that one means that it always takes e.g. 20 minutes to charge your batteries, regardless how many you're charging (because with a bigger battery, you're simply charging more cells in parallel, at the same speed per cell).
  - justaguy88 5y ago
    I've always wondered about this, do electric cars charge each cell in parallel? or are there some series connections?
Tossrock 5y ago
I've said for a while that electric planes are the perfect use case for aluminum-air batteries. Aluminum-air batteries have up to 8x the energy density of lithium ion, but are not rechargeable, so using them only makes sense if you have a system to recycle the used batteries. This doesn't make a ton of sense with cars, because cars are constantly going from random place to random place, and having to include a stop at a battery recycling center every ~1000km or whatever would be impractical. But planes go between very limited sets of known points, with huge amounts of infrastructure. Adding in the capability to do Al-air battery swaps / recycling would be easy, and the benefits for the use case (huge weight savings, faster turnaround times by swapping vs charging) are big.
- otterley 5y ago
  What's the process for recycling an aluminum-air battery? And is it cost/energy effective to do so? (If you think about it, closed-loop recycling of energy storage is just another form of recharging, but with extra steps.)
  - Infernal 5y ago
    From wikipedia[0] "it is possible to mechanically recharge the battery with new aluminium anodes made from recycling the hydrated aluminium oxide". I've found a few papers regarding recovery of aluminum from aluminum oxides, but I don't have the background to interpret them with an eye towards that process's impact on the overall efficiency of the battery. [0] https://en.wikipedia.org/wiki/Aluminium–air_battery https://en.wikipedia.org/wiki/Aluminium–air_battery
    - throwawayboise 5y ago
      Production of aluminum metal from aluminum oxide is hugely energy-intensive. Aluminum plants often have an on-site utility-size power plant to provide the electricity. Is this same energy needed to recycle the oxide from the batteries? If so it seems like a non-starter, maybe unless it could be done with solar generation.

nielsbot 5y ago

The "more info" page on their website says they are ruling out battery swaps, at least for now, since a battery swap would require a mechanical certification every time it was done. They are swappable though: they explain that used battery packs can be replaced and that used packs can be used for a second purpose with less stringent requirements. For example, an energy storage facility at the airport.

hutzlibu 5y ago

"Obviously this would be impossible if airframe designers incorporate battery cells in structural members, as some suggest to offset the weight penalty." Why not do both? Swap one part and charge just the internal batteries. But internal batteries does not sound so clever with limited lifetime anyway.

tgsovlerkhgsel 5y ago
Charging is limited by two factors: - the power you can get from the charger to the batteries - the power the cells can accept You can reasonably easily fix the first point with custom infrastructure, so the second point will be the limiting factor, and that one means that it always takes e.g. 20 minutes to charge your batteries, regardless how many you're charging (because with a bigger battery, you're simply charging more cells in parallel, at the same speed per cell).
- justaguy88 5y ago
  I've always wondered about this, do electric cars charge each cell in parallel? or are there some series connections?

Tossrock 5y ago

I've said for a while that electric planes are the perfect use case for aluminum-air batteries. Aluminum-air batteries have up to 8x the energy density of lithium ion, but are not rechargeable, so using them only makes sense if you have a system to recycle the used batteries. This doesn't make a ton of sense with cars, because cars are constantly going from random place to random place, and having to include a stop at a battery recycling center every ~1000km or whatever would be impractical. But planes go between very limited sets of known points, with huge amounts of infrastructure. Adding in the capability to do Al-air battery swaps / recycling would be easy, and the benefits for the use case (huge weight savings, faster turnaround times by swapping vs charging) are big.

otterley 5y ago
What's the process for recycling an aluminum-air battery? And is it cost/energy effective to do so? (If you think about it, closed-loop recycling of energy storage is just another form of recharging, but with extra steps.)
- Infernal 5y ago
  From wikipedia[0] "it is possible to mechanically recharge the battery with new aluminium anodes made from recycling the hydrated aluminium oxide". I've found a few papers regarding recovery of aluminum from aluminum oxides, but I don't have the background to interpret them with an eye towards that process's impact on the overall efficiency of the battery. [0] https://en.wikipedia.org/wiki/Aluminium–air_battery https://en.wikipedia.org/wiki/Aluminium–air_battery
  - throwawayboise 5y ago
    Production of aluminum metal from aluminum oxide is hugely energy-intensive. Aluminum plants often have an on-site utility-size power plant to provide the electricity. Is this same energy needed to recycle the oxide from the batteries? If so it seems like a non-starter, maybe unless it could be done with solar generation.