Amazon.com: GAXI Battery Replacement for Harman/Kardon Onyx Studio 1 Compatible with Harman/Kardon Onyx Studio 2, Speaker Battery : Electronics
Harman Kardon Onyx Studio 2 Battery - iFixit Store
2600mAh Battery 3.7V for Harman Kardon Onyx Studio 1 & 2 & 3 Player Li Polymer Rechargeable Accumulator Replacement+Track Code|Digital Batteries| - AliExpress
Amazon.com: 3000mAh Replacement Battery for Harman/Kardon Onyx Studio 4 : Electronics
Adding 18650 batteries to Harman Kardon Onyx portable speaker | Candle Power Forums
HQRP Kit: Battery and Charger for Harman Kardon Onyx, Onyx Studio Portable, Studio-2, Studio-3, Studio-4 Speaker ESX2567Q AU38AA-00 AU38AA-OO LI11B001F Wireless Speaker System AC Adapter plus Coaster - Walmart.com