Sennheiser Introduces PXC 550 Wireless Noise Cancelling Headphones with up to 30 Hours Battery | audioXpress
Sennheiser PXC 550-II Wireless - NoiseGard Adaptive Noise Cancelling, Bluetooth Headphone with Touch Sensitive Control and 30-Hour Battery Life (508337) - Newegg.com
New 700mAh Li Ploymer AHB413645PCT Replacement Battery For Sennheiser PXC 550 Accumulator Batterie 3 wire Plug +tools|Mobile Phone 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