This rechargeable Li-ion VL2020 3 V battery with 90-degree pins is a replacement cell used inside BMW remote key fobs. It is compatible with BMW 3-Series E46, E90, E91, E92, E93 / LX8, FZV, LX8FZV and also compatible with E83 X3, E53 X5, E9X, 5-Series E60, E61, 530i, 530xi, E39, Z4 E85, E86. When your key fob no longer holds a charge or becomes unreliable, replacing the internal rechargeable battery can restore everyday lock and unlock operation. Installation requires opening the key fob housing and soldering the pinned battery to the circuit board, so electronics tools and technical ability are required; if you are unsure, have a specialist perform the replacement. Disclaimer: This is not an Original Equipment Manufacturer (OEM) product, HQRP branded product is a replacement. All brand names and logos are registered trademarks of their respective owners. Any use of the brand names or model designations for this product are made solely for purposes of demonstrating compatibility.