Duracell 389/390 Watch Battery (SR1130W) Silver Oxide 1.55V (1 PC). With a long-lasting charge that requires fewer recharges, Duracell Specialty and Rechargeable batteries really do set themselves apart from the rest.
Li-ion MD-390 Battery Pack TYT MD 390 MD-UV390 DMR Radio 7.4V 2200mAh Battery for MD-390 TH-UV8200 Digital Radio TYT Accessory - AliExpress Cellphones & Telecommunications