The SM1 Slim Mechanical Backlit Bluetooth Keyboard uses a built-in lithium-ion battery that is not replaceable.

Battery specifications:
- Input: 5V ⎓ 0.8A  
- Capacity: 2500mAh  

Low battery behavior:
When the battery voltage drops below 3.5V, the LED on the spacebar will flash slowly. At the same time, the backlight will turn off and the keyboard will enter power-saving mode.

Charging:
A full charge typically takes 2–3 hours.