Why does the charging procedure continue after 5 hours?
When you use your device for the first time or haven't used it for a long period, charging might take longer.
Generally, the charging procedure should be finished within 5 hours even when it is fully discharged.
Make sure that the device (charger, adapter) is connected continously during charging, as this might interrupt your charging session.
If the charging indication will not stop, even after 24 hours, charging light has a malfunction. The charging and the massager are not working properly. This malfunction will not cause any "harm" to you or the massager. You can still use the massager.
If you have doubts about the malfunction, the massager and the charger should be replaced.