For years, I watched without understanding why my wife's iPad could sit in standby for weeks and still hold a charge, while mine would drain in two days without even being used. This went on for years - both are 2020 models and lightly used.
A week ago, by chance, I stumbled upon a post from someone mentioning that keeping the Pencil and Magic Keyboard attached, even when not in use, kills the battery in just a few days. I had never made the connection. Over a week ago, I disconnected everything and put the iPad in standby, connected to Wi-Fi, with 78% battery. I just turned it on: 54%.I can only think about how much I’ve needlessly ruined the battery over these six years out of ignorance (or was it inefficiency?).