Power The POPMIDI-BT is a compact, portable radio & speakers from Pure that uses either 5.5V DC connection or 230V AC connection if you want to use the mains to power this device or you can use Pure's Charge PAK D1 Rechargeable Battery which is very easy to fit & is reliable, you can also use four normal Alkaline AA batteries to power this pack & can be powered for up to 24 hours whilst using the Charge PAK but can be considerably less with regular batteries. Radio The Digital & FM Radio frequencies featured on the Pop Midi are DAB/DAB+ with 87.5-108 MHz so you have plenty to listen to, but if radio is not your pick, then there is also an Aux-in for you to listen to your favourite music from your iPod or Smartphone.