@hanns76,Johann, Maybe for initial charge let it charge 8 hours. Try the JBL to see if it work's, if it works run the battery down till it is low(not dead, just low) and repeat charging to see if charge times get better, do this a few times and it continues not charging to full capacity the circuit inside speaker or charger may be defective and should be returned for refund/replacement while you can through the store. Good luck. I hope this helped you out, if so let me know by pressing the helpful button.