Remember Battery state

Scope

Both

Problem or use case

when the airpods are not connected for a while, the phone (or Linux machine) does not remember its last battery charge state, meaning that when you leave your airpods laying around on the kitchen table for a day, and then want to know if they need charging, or what battery percentage they're at, you need to go get them and open the case to refresh it.

in case of them just laying around the whole day doing nothing, the percentage will not have changed meaningfully.

Proposed solution

• have the UI show the last known battery state.
• maybe with some icon showing that it is not the current state, or how long it's been since an update
• it would probably make sense to add a toggle in settings for this behaviour.
• this behaviour would be especially beneficial in the widget, because it just says 0% if the airpods have been disconnected for a while. (widgets are getting reworked though, according to kavishdevar

Alternatives considered

a timeout (configurable?) for the percentage, to specify whether its outdated or up to date

No files or tests are named. Start by tracing the UI, widget, and settings paths for battery state on Android and Linux, then determine where the last known value and its age can be retained. Done means disconnected AirPods show their last known percentage with an outdated-state indication and the proposed settings behavior is covered.