Bluetooth and the mystery of the 20%

[Kallen]

i googled this and found not a single thing. Every Bluetooth device I have beeps then shuts down at 20% battery. I have two earbuds (different brands) and two Bluetooth receivers (the kind you plug into wired headphones or your car). Why do these devices shut down with 1/5 battery remaining?? Because this is multiple devices across do...is this an iOS thing? If so how do I change it?

 

[NoBoMac]

Guessing not iOS 12, it's your devices.

Example, I have two sets of earbuds, both acquired earlier in the year, both started out on iOS 11. The one set of buds starts to low charge beep at about 20% theoretical left. The other set, bigger battery, beeps at 10%. Theoretical in that advertised playback time is X hours, and I'm getting something not quite. Usual disclaimers in that if using at a higher volume level, that will reduce charge life (which explains my case in that at times, I up the volume to block outside noise).

On iOS 12, not seeing anything different.

So, depending on device, how old the battery is in devices, and probably a number of other things, can see unexpected shutdowns.

And: how do you know that the Bluetooth device is exactly at 20%?

 

[Kallen]

Guessing not iOS 12, it's your devices.

Example, I have two sets of earbuds, both acquired earlier in the year, both started out on iOS 11. The one set of buds starts to low charge beep at about 20% theoretical left. The other set, bigger battery, beeps at 10%. Theoretical in that advertised playback time is X hours, and I'm getting something not quite. Usual disclaimers in that if using at a higher volume level, that will reduce charge life (which explains my case in that at times, I up the volume to block outside noise).

On iOS 12, not seeing anything different.

So, depending on device, how old the battery is in devices, and probably a number of other things, can see unexpected shutdowns.

And: how do you know that the Bluetooth device is exactly at 20%?

Because on my iPhone is shows the devices are at 20% under the Batteries widget when I swipe to the left. I just thought it's odd that all my devices beep and shut down at 20%.