The HF69B Bluetooth enabled Stereo Audio Amplifier Module puts out a max. power of 6W per channel, and can run on a rechargeable single cell lithium battery (3.7V). A charging circuit and the battery connector is already on board. The modern Class-D design with an efficiency of about 90% does not require any heat sink.
This amplifier module is the perfect choice for battery operated, wireless stereo speakers. Just bring you old speakers up from the basement, get for example a 18650 standard lithium cell, and turn the old boomer into a pair off powerful, wireless speakers for your RV or the pool party.
With the on-board switch in ON position, the USB port is the charging port, and your setup would require a lithium battery connected. In OFF position the USB port is the power supply port, and you can run the amplifier without a battery.
Bluetooth pairing starts automatically after powering it up. The Bluetooth name is “Xpecial Audio”.