New Xiaomi Mi Band 4 fitness tracker came with us from the factory with 57% charge – this is where our battery test began. We discharged it to “zero”, loading in all possible ways. How long it took and in which mode the tracker worked – we tell in a detailed report below.

We had a smartphone with Bluetooth 4.2 LE, but the fitness tracker supports Bluetooth 5.0. The brightness of the display was set to 3 out of 5, every 10 minutes the pulse measurement was determined and the tracking function was started on the quality of sleep.

We decided not to limit ourselves to anything, so we used the capabilities of the bracelet to the fullest. Notifications of calls, SMS, messages from instant messengers, calendar events and weather changes have been activated. So the tracker worked on weekdays, and on weekends it was all supplemented with a few hours in the cycle training mode. It is not yet known whether the monitoring of sports activities affects energy consumption, but a maximum was squeezed out of the device.

In the early days, the tracker was used actively: a familiarity was held with the abilities of innovation and tuning. You can read about it at the first look and unboxing of the Xiaomi Mi Band 4. As a result, battery discharge increased – 10% and 11% respectively.

After completing the tracker’s receipt and disconnection, it lasted 6 days and 16.5 hours. That is, after some few minor changes in settings, battery consumption in the normal use was slightly less than 8% per day. Note that the manufacturer claims work for 20 days without recharging – this result seems quite reliable with less active use. For example, after shutdown the heart rate and sleep monitoring, there was a significant increase in battery life.

During the test, we saw a strange behavior in the charge indicator of the fitness tracker. It hung for a long time at around 33% and then quickly dropped to 28%. It is possible that during the first run, there was no time for the battery to calibrate properly. This happened only once and never happened again.

The tracker informed about the full discharge with a vibration signal, and then just turned off. From the 10W (5V / 2A) adapter, the tracker was charged from 0 to 100% in 1 hour 40 minutes.

For the sake of the experiment, after a full charge, we included a more frequent, minutely pulse measurement. When you save the rest of the settings, the battery of the device has changed in the lower direction, which is interesting. In four days the device was discharged by 28%. Thus, in the above scenario, the use of the Mi Band 4 battery should be enough for 12-15 days of work without recharging.

The Xiaomi Mi Band 4 fitness tracker has been already on sale via Amazon.com.