Your UPS gives you three minutes of runtime and then your servers go dark. You don't need a new unit. You need more battery on the one you already have. The APC SMX120BP plugs straight onto an operating Smart-UPS X and extends your runtime immediately. 120V lead-acid pack, 4U rackmount or tower. Stack a second one later if the next blackout runs longer than you'd like. Precision charging and intelligent battery management keep the cells healthy so you're not chasing a dead pack at 6am on a Friday. Comes with the battery pack, an installation guide, and rack-mounting brackets (AP9625 or AR201). Check your Smart-UPS X manual to confirm your model takes this pack before you order. Add to cart when you're ready