Sony CECH-2102A Instruction Manual page 23

Using the controller wirelessly
If you disconnect the USB cable, you can use the controller wirelessly.
To use it wirelessly, the controller's battery must be charged.
Hints
 The USB cable can be connected or disconnected while the controller and the
system are turned on.
 If the controller does not function, press the PS button, and then reassign the
controller number.
Charging the controller
With the system turned on (power indicator is lit solid green), connect
the controller to the system using a USB cable. The port indicators of
the controller flash slowly and charging begins. When charging has
completed, the port indicators stop flashing.
Hints
 The controller can be used while charging.
 Charge in an environment where the temperature range is between
10°C - 30°C. Charging may not be as effective when performed in other
environments.
 The controller cannot be charged when the system is off (in standby mode).
Battery charge level
If you press and hold down the PS button for more than one second,
you can check the battery charge level on the screen.
The battery has plenty of charge.
The battery has started losing its charge.
The battery charge level is low.
The battery has no charge. The port indicators on the controller flash
rapidly. Charge the controller.
Hint
Depending on the environment or the conditions of use, the remaining charge
level may not display correctly and the battery duration may vary.
Charge Level
23