Thanks for your feedback. The published playtime for our Onyx Studio 8 reflects the maximum battery life at low volume with no bass boost. Higher volume levels and bass‑heavy audio will naturally reduce battery performance. To check whether the battery is functioning properly, fully charge the speaker and play music at very low volume with no bass enhancement. If the playtime is close to the advertised specification, the battery is performing normally. If you have any questions, please contact us directly at: https://support.jbl.com/us/en/#contact"