AHB413645PCT Battery Replacement for Sennheiser PXC 550 Headphones
Amazon.com: 1000mAh Replacement Battery for Sennheiser PXC 550 II Noise Cancelling Wireless Bluetooth Headphones : Electronics
Sennheiser PXC 550-II Wireless - NoiseGard Adaptive Noise Cancelling, Bluetooth Headphone with Touch Sensitive Control and 30-Hour Battery Life (508337) - Newegg.com
Review: Sennheiser's PXC 550 Wireless Headphones Should Put Bose on Notice - MacRumors
Sennheiser's new PXC 550 wireless headphones are rated for 30 hours on a single charge - The Verge
Amazon.com: MPF Products 700mAh AHB413645PCT Battery Replacement Compatible with Sennheiser PXC 550 PXC550 Noise Cancelling Wireless Bluetooth Headphones : Electronics
Sennheiser PXC 550 Wireless Review - RTINGS.com
100% New 700mah Ahb413645pct Battery Wireless Bluetooth Headset For Sennheiser Pxc 550 Battery Ahb413645pct - Digital Batteries - AliExpress
I recently bought PXC 550 ii, this is the second time I charge it, it's been more than three hours already and the third led is still blinking (internet says full charge