Try this
1.When you open the case while the earbuds are in the case, the indicator light indicates the battery level of the earbuds. If it’s red, you need to place them in the charging case and charge them.
2.If you close the case while the earbuds are inside, the indicator light indicates the battery level of the charging case.
If it’s red, you need to charge the charging case using a USB cable or wireless charger.
In addition, you can check the battery status of your TONE Free on the TONE Free app.