Plantronics 86180-01 Spare Battery for CS540  - Retail Packaging Replacement for: 86180-01, PL-86180-01 & 84479-01 Batteries. Compatible with the following models: Plantronics CS540 Wireless headset 3.7V 140mAh 0.55Wh Li-Polymer Battery Up to 9 hours talk time with the SC540 headset