Synergy Digital Speaker Battery, Compatible with JBL PartyBox 300 Speaker, (Li-ion, 7.4V, 10400mAh) Ultra High Capacity, Replacement for JBL SUN-INTE-125 Battery Specifications: Battery Chemstry: Li-ion Voltage: 7.4V Capacity: 10400mAh Compatible with: JBL SUN-INTE-125 Battery Works for: JBL PartyBox 300 Speaker and many more