Yamaha TW-E7B Noise-Canceling True Wireless In-Ear Headphones (White) - Manual (Page 12)

Charging the charging case
To charge the charging case, connect the included USB power adaptor.
CAUTION
( The charging case is not waterproof. Do not expose this product to liquids such as sweat, rainwater or seawater.
( Be sure to use the USB power cable that was included with this product.
( When using a USB power adaptor, be sure that the commercially-available adaptor is compatible with 5 V DC (at least 0.5 A)
power output.
( When charging this product inside of China, be sure to use a USB power adaptor that is approved by CCC.
( Recommended charging temperatures: 10–35ºC
1
2
3
Front
Charging indicators
Type C
Type A
USB power adaptor
(commercially available)
1
Plug the USB power cable (type C side) into the charging case.
2
Plug the USB power cable (type A side) into the USB power adaptor.
3
Plug the USB power adaptor into the power outlet.
Charging will begin. Charging takes about 3 hours.
While the case is charging, the indicators light up as shown below.
Remaining battery power Indicator
100%
75–100%
50–75%
25–50%
12
Charging and Powering > Charging the charging case