Does Bluetooth drain the battery?

Yes, using Bluetooth does drain the battery of your device, though the extent depends on several factors.

1. Energy Consumption of Bluetooth: Bluetooth consumes a small amount of power compared to other features like Wi-Fi or cellular data. However, it's still an active process, so it can drain the battery over time, especially if it's constantly searching for devices or transferring data. Bluetooth Low Energy (BLE) technology, which is used in newer devices, is more efficient and helps to minimize power usage.

2. Device Usage: The more you use Bluetooth, such as for continuous streaming of audio or data transfer, the more battery it will consume. For example, streaming music through a Bluetooth speaker or earphones can drain your phone or laptop battery faster than when Bluetooth is idle or used for less intensive tasks like connecting to a keyboard.

3. Connection Duration: Keeping Bluetooth turned on when not in use can contribute to a gradual drain. It’s better to turn off Bluetooth if you're not actively using it to preserve battery life.

In general, Bluetooth isn’t a major battery drain, especially with newer versions of Bluetooth that are more energy-efficient, but like all wireless technologies, it does consume some battery when actively in use.