So many times I forget to plug the deck or someone uses the charging cable for something else and I come back to play the next weekend and the deck is at 0%. Why doesn’t the deck have a deep sleep or hibernate mode on by default like my laptop or iPad?
Iirc the SD does discharge from full battery a bit when plugged in for a while to preserve battery health.
It lets the battery discharge to 90% while plugged in. If you’re not using it for a few days you should still unplug.
It will still keep it above 90% all the time which is bad according to most comments I just found by googling about it, it’s just the nature of lithium batteries. Steam deck allegedly has a feature to use direct power from outlet if in use while charging and if at max, but it still keeps battery at high %.
Most of that is really old knowledge from before the days of sophisticated charge controllers.
Maintaining a high SoC is still very damaging to battery life.
Which is why the charge controller does not do it. It will drop to a sustainable voltage when it detects longer wired connection after being charged and adjusts the “percentage” it shows you accordingly so you still see a 100 to 0.
Do you have anything to back that up with or are you speaking from personal incredulity? What you said certainly does not apply to e.g. contemporary smartphones.
Contemporary smartphones tend to push things a bit harder to offer the “best” performance in the first few weeks. Though I have to say comparing today’s newest phones with phones from 2015, battery management has gotten a lot softer.