3 ms·

Take off power surge is one of the few areas that electric aircraft actually are well suited for. Batteries of specific power high enough are not uncommon.

blagie 5y ago
The problem raised in the video was that high take-off power draw would age the batteries quickly, not that it was impossible. I haven't run the numbers to see if they were right.
- Robotbeat 5y ago
  But you’re starting off in the best possible part of the flight, when battery voltage is highest. A burst of power there has the least bad impact. Also, if you have a large battery, the amount of power you can afford for burst is extremely high. It’s also possible to have a battery optimized for high discharge assist the main battery, like a hybrid vehicle. But that’s unlikely for most battery chemistries which have plenty high C-rate that a secondary power-optimized battery is totally unnecessary.
  - Leherenn 5y ago
    Well, if you only do one flight per charge, yes. One of the club around here tried to use an electric plane for instruction, and the constant takeoff/landing cycles killed the battery real fast.
- _dain_ 5y ago
  Could you have some kind of slingshot on the runway to accelerate the plane, take some of the work off the batteries? Like what they have on aircraft carriers.
- CoastalCoder 5y ago
  I wonder if a low-performance version of a carrier catapult would work. Perhaps a simpler / cheaper version would be a specialized winch at the end of the runway. Obviously it would limit the airstrips from which an electric plane could embark, but maybe that's an acceptable trade-off.
  - Robotbeat 5y ago
    That’s precisely what Zipline does, which is the only operational cargo electric plane company.
  - nradov 5y ago
    Gliders are already launched using winches at some airfields. https://www.camgliding.uk/about-gliding/launch-methods/ https://www.camgliding.uk/about-gliding/launch-methods/
  - polishdude20 5y ago
    You could even have a cable that travels with the plane while it's on the runway providing all the power you need and when the plane takes off, the cable comes off and the plane uses its own battery.
thehappypm 5y ago
Yeah, I mean you can put a bunch of AAA batteries in parallel to get an arbitrary amount of current!

blagie 5y ago

The problem raised in the video was that high take-off power draw would age the batteries quickly, not that it was impossible. I haven't run the numbers to see if they were right.

Robotbeat 5y ago
But you’re starting off in the best possible part of the flight, when battery voltage is highest. A burst of power there has the least bad impact. Also, if you have a large battery, the amount of power you can afford for burst is extremely high. It’s also possible to have a battery optimized for high discharge assist the main battery, like a hybrid vehicle. But that’s unlikely for most battery chemistries which have plenty high C-rate that a secondary power-optimized battery is totally unnecessary.
- Leherenn 5y ago
  Well, if you only do one flight per charge, yes. One of the club around here tried to use an electric plane for instruction, and the constant takeoff/landing cycles killed the battery real fast.
_dain_ 5y ago
Could you have some kind of slingshot on the runway to accelerate the plane, take some of the work off the batteries? Like what they have on aircraft carriers.
CoastalCoder 5y ago
I wonder if a low-performance version of a carrier catapult would work. Perhaps a simpler / cheaper version would be a specialized winch at the end of the runway. Obviously it would limit the airstrips from which an electric plane could embark, but maybe that's an acceptable trade-off.
- Robotbeat 5y ago
  That’s precisely what Zipline does, which is the only operational cargo electric plane company.
- nradov 5y ago
  Gliders are already launched using winches at some airfields. https://www.camgliding.uk/about-gliding/launch-methods/ https://www.camgliding.uk/about-gliding/launch-methods/
- polishdude20 5y ago
  You could even have a cable that travels with the plane while it's on the runway providing all the power you need and when the plane takes off, the cable comes off and the plane uses its own battery.

thehappypm 5y ago

Yeah, I mean you can put a bunch of AAA batteries in parallel to get an arbitrary amount of current!