S7 charger output voltage is 5V, the maximum current is 2A, that is, the maximum output power is 10W; The S8 charger output voltage can be 9V or 5V, the maximum current is 1.67A or 2A, that is, the maximum output power can be 15W or 10W, depending on the charger model you are using. Therefore, the two mobile phone chargers are not the same and cannot be mixed. If you are not sure which charger to use, please refer to the specification list of the original charger of the phone, or consult the official customer service of the phone brand.
The charger for the S7 and S8 is not universal. Although their charging ports are similar, their chargers have different power outputs, so different chargers are used.
The S7's charger output is 5V\/2A, while the S8's charger output is 9V\/1.67A or 5V\/2A (depending on the region). Mixing chargers may affect the charging speed of the phone and may even damage the phone.