HSABAT 2000mAh LIP 8 LIP8 Battery for SONY MZ R50 MZ R50S 14650| | - AliExpress
Amazon.com: Synergy Digital Player Battery, Compatible with Sony LIP-880PD-B Player, (Li-ion, 3.7V, 980mAh) Ultra High Capacity, Replacement for Sony LIP-880 Battery : Electronics