I‘m not sure if replaceable means that. In fact I am very doubtful replaceable means you can replace it like older laptop batteries or Gameboy batteries. It‘s more like replacing a 3DS battery I imagine. So no, very much not be at 100 percent just like in the old days unless you regularly replaces your 3DS batteries. Not sure why you would.
But you can always carry a second battery and be at 100 percent instantly like the old days (2012)
I‘m not sure if replaceable means that. In fact I am very doubtful replaceable means you can replace it like older laptop batteries or Gameboy batteries. It‘s more like replacing a 3DS battery I imagine. So no, very much not be at 100 percent just like in the old days unless you regularly replaces your 3DS batteries. Not sure why you would.
Real gamers skip the batteries and have their GBA on AC… Hoping mom doesn’t step on the cord and yank it out again.