Battery for Harman Kardon Onyx Studio 1, 2 and 3 Wireless Bluetooth Speaker - Gippokrat
Harman Kardon Onyx Studio 3 Portable Bluetooth Speaker with Rechargeable Battery - Black - Walmart.com
Harman/Kardon Onyx studio 3 Replacement Battery: BatteryClerk.ca
3500mah Replacement Battery For Harman Kardon Onyx Studio1, 2 Speaker Mini Bluetooth Speaker Battery Replacement, New High Spee - Rechargeable Batteries - AliExpress