New 650mAh Replacement Battery for Microsoft Zune 1st Gen 30GB Replaces the following battery part numbers: JS8-00001 / JS8-00002 / JS8-00003 Replaces the following part numbers: 1089 1090 1091 1092 For best results for li-on batteries, please FULLY CHARGE the item overnight, and then on its first use, FULLY discharge the item. (Use the item until it fully depletes its battery after its first charge) DISLCAIMER: The names for Microsoft Zune, etc. are used for the sole purpose of describing the compatibilty of our items and identifying models they work with. These names are the copyrights of their respective owners. MCMConcepts does not intend to infer any connection / ownership / affiliation between MCMConcepts and any other company.