Some Galaxy users who installed Samsung’s new interface One UI 9.0 update are reporting that their phones are charging slower compared to the previous software version. Complaints are particularly concentrated in the Galaxy S25 series, but similar situations are also encountered in older Galaxy models.

One of the most striking changes in the shared measurements is seen on the Galaxy S25+. It is stated that the charging power, which remained above 40W until the battery level reached 25% in the One UI 8.5 version, dropped to 34W at the 13% level after One UI 9.0.

Charging Power Changes and User Experiences

The user conducting the test notes that despite cooling the device to prevent the temperature from affecting the result, the power dropped to around 34W when the battery reached 13%. When the cable was unplugged and plugged back in, the phone briefly exceeded 40W, but after about 10 seconds, the power dropped back to 34W.

Similar complaints are also voiced by Galaxy S25 Ultra users. One user reports that they tried charging with Samsung’s official Super Fast Charging 2.0 charger as well as an adapter from a different manufacturer, and in both cases, the charging was slower.

The problem doesn’t seem to be limited to the Galaxy S25 series. Some Galaxy S24+ owners using the One UI 9.0 beta version also report that the time spent at high power, especially in the first part of charging, has shortened.

Complaints highlight that both the maximum charging power achieved and the duration for which this high power level can be maintained have changed. Samsung has not yet confirmed that it has made any conscious changes to the charging profile of Galaxy phones with One UI 9.0.

Update and Security-Focused Restrictions

Due to recent incidents involving the Galaxy S25+ and battery fires, it is being speculated that new temperature and security-focused restrictions may have been implemented in charging management. However, there is no confirmed link between the charging changes in One UI 9.0 and these incidents.

Slow charging may not be solely due to software. In Galaxy phones, charging power can be automatically reduced when the device temperature rises; the adapter used, USB cable, battery housing options, and the condition of the charging port can also affect the speed.

However, the difference in power levels in comparative measurements made with the phone and charging equipment before and after One UI 9.0 is causing users to focus directly on the update. Currently, there is no bug identified by Samsung or a prepared fix update.

There is also no definitive data to suggest that all Galaxy phones using One UI 9.0 exhibit the same behavior. Whether a system-wide change has been made to the charging curve will become clear with measurements on different models and battery levels, and Samsung’s statement. Have you noticed a similar slowdown in charging on your phone?