The reasons for this issue are as follows:
1. If your watch is not charged in time after low power shutdown, or has not been used for more than two months, the device battery needs a longer charging time to activate the battery due to excessive discharge;
2. If the watch has been stored in a very cold or hot environment, the battery temperature could affect charging speed;
3. Dust, dirt, or corrosion on the charging pins or contacts of the watch and charger can interfere with the connection, leading to slow charging;
4. Using a charger or cable that is faulty, not compatible, or low quality could result in slow charging speeds, especially after long periods of inactivity;
5. Long periods of inactivity can lead to battery degradation, especially if the battery is left completely drained. This degradation can cause the battery to charge more slowly.