How to Change JBL E50BT or E40BT battery replacement DIY - YouTube
Amazon.com: Linkidea Replacement Audio Cable with Mic Compatible with JBL E55BT E50BT E45BT E40BT E35 E30 E65BTNC 650BTNC S700, 2.5mm TRS to TRRS Aux Cord with Inline Microphone and Volume Control (5ft/1.5m) :