Keep critical infrastructure running longer when utility power drops. The APC SRTL180RM2UBP external battery pack is built for Smart-UPS Online lithium-ion systems that need more runtime without moving to a larger UPS chassis. Its 180 V battery architecture supports demanding rack and tower environments where uptime matters more than convenience. This 2U unit fits cleanly into space-constrained deployments and pairs with APC online UPS platforms to extend backup duration for servers, storage, network gear, and edge systems. Lithium-ion chemistry helps reduce maintenance overhead compared with traditional valve-regulated lead-acid battery packs, while preserving the runtime extension needed for controlled shutdowns or ride-through during longer outages. For teams standardizing on APC infrastructure, this battery pack is a practical way to scale protection as load profiles grow. It is a better fit than lower-cost replacement batteries when the requirement is sustained runtime, predictable integration, and a form factor designed for enterprise rack environments.