Lithium Ion batteries would burn out, burst into flames if the charger didn't stop requesting power when they got full. It's logical to assume that the iPad reduces charge and turns it off when the pencil reaches 100%.
I've stored the pencil for some time away from the iPad and it will report 100% (quick connect to find out) but drop like a brick with usage (2-3 hours) vs - staying at a high charged % when I leave it connected to the iPad.
I do a lot of reading so I don't like the pencil to be connected to the iPad at all times - I find I'm always moving it with my fingers as I try to read - plus the iPad is a tad bit lighter without the pencil. But when stored at night, during work travel? The pencil is always connected.
I'm seeing no noticeable battery difference vs leaving the pencil connected vs not (on the iPad).
As far as the "wireless charging mechanism" - it's so frigging tiny... so minuscule... so small... I wouldn't be worried about that... if you're worried about that, you should be worried about the wifi transmission, bluetooth, cellular, rays from space and the sun...
Just like an Apple Watch charger - it's not drawing power until you place the watch on the cable and then it starts drawing power or any other wireless charger for the last few years. I've tested this with a Kill-A-Watt.
[automerge]1586747090[/automerge]
Yeah, I would like this. I don't want the pencil to be charged if its battery is above 50 %. Because of this I put the pencil on the iPad only when I want to charge it. Otherwise I store it in a front pocket of the sleeve I use for protecting the iPad.
I would love this feature... keep the battery at 50, or even 80% charge. I rarely use my pencil for more than an hour or two... it would probably help the longevity of the battery for all my electronic devices if I could keep them at a 50-80% charge.
That said... my wife and I have HEAVILY used an Apple Pencil generation 1 for 2+ years ... it was still a champ when we got rid of it. I am not worried at all about prolonging the life of my Apple Pencil battery, especially for the cost of the device.