@georgetakei One possibility is that the charger connections at the bottom of one pod are not making contact or are dirty/corroded, so that pod is not getting fully charged.
@georgetakei It is likely the battery life/ quality of the battery is lower on one. Annother issue could be water damage or some other sort of damage or manufacturing defect. The damage may not be outwardly visible but it has been known to happen.
@georgetakei typically only one ear phone gets the audio via Bluetooth and then relays it to the other ear. So one side is just receiving and the other both receiving and transmitting.
@georgetakei One earbud acts as the "host" earbud which connects to your phone. This earbud then plays audio and also beams it to the other earbud, which increases battery usage for the host bud.
@georgetakei
This also happens with regular hearing aids, my dad has a pair that talk to each other via bluetooth so they are quite a modern set of aids.
They do however use single use batteries and beep when low to indicate when they need replaced. Both aids never beep at the same time but he does replace the batteries in both when one set beeps as the other would start beeping within a relatively short period of time to be replaced.
It's possible, that one is not that firm into the loading case (had that one time or another) and just doesn't load properly. Those magnets don't hold every bump. 😏
Noice Cancelling! Noices come from different directions, so one AirPod is more active then the other.
Phone calls etc. The system decides, which AirPods Mic is used - and can switch it in real time. So there can be one used longer or more often than the other.