inputs.text: battery - since yet try mp3 player like much zen touch 20gb decided try new battery old one maybe 60 minutes play time new would last 8 hours easily received new battery started install noticed wires opposite side plug old one yikes reverse polarity not good changed works played three hours charging overnight still showed two three bars left im glad noticed polarity issue plugging dont know zen builtin protection damage due reverse polarity id rather not find hard way doesnt hadnt polarity issue would given four stars since seems work well oem new