For Boka 2.0 brush:

We recommend charging the toothbrush at least 8-12 hours. There is no full charge indicator, but the charging base will light up in red when it's charging and turns off once fully charged.

For Boka 3.0 brush:

The toothbrush needs to be fully charged for ≤16 hours.

When the red charging indicator flashes or the product fails to power on, it signals a low battery and requires charging. During charging, the red indicator lights up between 10% and 90% battery, then turns off once fully charged.