If the headset is not used for a long time, the indicator (red) may not light up when you connect the micro- USB cable to charge the headset. Wait for a specified amount of time until the indicator (red) lights up. If the headset detects a problem while charging due to following causes, the indicator (red) may turn off, although charging is not complete. In this case, charge again within the charging temperature range. If the problem persists, consult your nearest Sony dealer. A commercially available USB AC adaptor capable of supplying an output current of 0.5 A (500 mA) or more Personal computer Time required for charging the empty battery to its full capacity. The time may be different depending on the conditions of use.

Charging the headset - Sony Help Guide | Charging the headset - Sony

If the life of the built-in rechargeable battery drops significantly, the battery should be replaced. Consult your nearest Sony dealer for replacement of the rechargeable battery. If the headset detects a problem while charging due to the following causes, the indicator (red) flashes. In this case, charge once again within the charging temperature range. If the problem persists, consult your nearest Sony dealer.If the headset is not used for a long time, the indicator (red) may not immediately light up when charging. Please wait a moment until the indicator lights up. The headset cannot be charged when the computer goes into standby (sleep) or hibernation mode. In this case, change the computer settings, and start charging the headset once again.

Charging the headset - Sony WH-1000XM5 | Help Guide | Charging the headset - Sony

The remaining battery charge of the headset is not displayed on the screen of an iPhone or iPod touch. Connecting the headset to both a music player and a smartphone / mobile phone (multipoint connection)If the rechargeable battery has not been used for a long time, its duration may shorten. However, the battery life will improve after a few recharges. If you store the headset for a long time, charge the battery to its full capacity once every 6 months to avoid over-discharge. You can use the headset by connecting the supplied headphone cable, even while charging the headset. If the headset is not used for a long time, the indicator (red) may not light up when you connect the micro-USB cable to charge the headset. In this case, do not disconnect the micro-USB cable from the headset: wait a few minutes until the indicator (red) lights up. If you store the headset for a long time, charge the battery to its full capacity once every 6 months to avoid over discharge.