Upgrade your notebook's performance with the BTI L21L4P71-BTI rechargeable battery. With a robust 52.5WHR capacity, this 15.44V lithium-ion battery ensures long-lasting power for your device. Designed specifically for compatibility with proprietary battery sizes, it fits seamlessly into your notebook, providing reliable energy for all your tasks. Whether you're working on the go or enjoying multimedia, this battery delivers the performance you need. Say goodbye to unexpected shutdowns and enjoy uninterrupted usage with the BTI L21L4P71-BTI battery!