Sony BP-HP550-11 Cordless Phone Battery Ni-MH, 2.4 Volt, 700 mAh
BP-HP800-11 Sony 2.4V 800mAh Nickel Metal Hydride Rechargeable Battery
Genuine SONY BP-HP550 replacement battery Used MDR-RF970R RF925R RF912R RF4000K | eBay
Sony BP-HP550-1 Battery for Wireless Headphones
Sony MDR-970RK Battery - Replacement for Sony BP-HP550-11 Headphone Battery (700mAh, 2.4V, NI-MH) - Walmart.com
Amazon.com: Replacement for Sony BP-HP550-11 Battery - Compatible with Sony BP-HP550-11 Headphone Battery - Compatible with Sony MDR-RF860 MDR-RF4000 MDR-RF970 MDR-RF970RK MDR-RF925 (700mAh 2.4V NI-MH) : Electronics
Amazon.com: 2 Pack - Replacement for Sony BP-HP550-11 Battery - Compatible with Sony BP-HP550-11 Headphone Battery - Compatible with Sony MDR-RF860 MDR-RF4000 MDR-RF970 MDR-RF970RK MDR-RF925 (700mAh 2.4V NI-MH) : Electronics
Sony BP Hp550-11 Headphone Batteries – Battery World