I bought a used car (3000gt) with the Kenwood KDC-HD548U already in it. I made a cd with MP3 file types and according to the Kenwood site it should be able to read MP3, WMA or AAC files. however after giving up on MP3 Files i tried ACC with no different results. So i researched the problem and read up about how it will read MP3/ACC/WMA until the internal battery life dies that is. I did further research but was unsuccessful in finding a way to recharge, or replace the battery. i even took it apart my self to find no battery, nor spot for a battery inside. please help me.