The NiMH batteries in the Neuros and the Lithium Ion battery in the Neuros HD are expected to last at least 1 ½ - 2 years (depending on usage). Only our Neuros technical team can replace the battery for you and, as a result, it is not consumer-serviceable. Our battery replacement policy is as follows. Within Warranty (90 days parts, 1 year labor) -If within first 90 days of purchase - NO CHARGE -Past 90 days, but within 1 year- $7 Outside of Warranty Neuros 128- $8 Neuros HD- $12 To have your battery replaced, please contact customer support for instructions via email at support@neurosaudio.com or by phone at 866-5-NEUROS.