On Saturday, March 6, 2021 at 2:03:25 PM UTC-5, Eric Greenwell wrote:
Kenn Sebesta wrote on 3/6/2021 10:31 AM:
I predict that people just want to launch. If we can use 8-10kg of 20C LiPos to get to 1k', with 5 minutes of cruise left over, and a freshly charged pack waiting on the ground, then it's basically a winch launch. And as those of us who have flown in the EU know, winch launches are great ways to get flying.
I know people want much more than a launch! Note that sustainers are sold by all the major
manufacturers; actually, pretty much all the manufacturers.

You might be right! I think we're looking at this same coin from two different sides. I'm at the stage of my gliding career where just getting up and staying up is the goal, whereas you are quite a lot more accomplished and value the ability to get home after a long flight. It's tough for me to guess which direction the larger market needs, we'll see what it ultimately decides. As you point out, it's very easy to adjust the amount of available battery energy.

A corollary to your density remarks is doubling the battery capacity of that "launch only" glider won't add significant weight or cost, and would enable a couple of saves or a self retrieve.

For sure! Although keep in mind that the battery is the single highest $ component of the propulsion system. Moreover, batteries have a fixed lifespan with or without use, so some people might prefer a lower TCO and a lighter plane. I think the beauty of electric is the ability to tailor this to specific needs. We can even imagine the same plane with a lightweight pattern launch battery, and a heftier XC battery.

The genius of all this is that as battery tech improves the existing plane just gets better and better. When you're looking at your replacement pack 5-10 years down the road you'll automatically benefit from all the improvements and your new pack will either be cheaper, or it'll fly longer, or it'll be lighter. Maybe all three. Certainly never saw 100LL get cheaper, better, and lighter!