APC Smart-UPS C-1500-rack mountable battery SMC1500i-2UC.
Replacement APC Smart-UPS C-1500-rack mountable battery, rechargeable VRLA sealed batteries for the SMC1500i-2UC uninterruptible power supply.

The APC SMC1500i-2UC is a rack-mountable 1500VA 900w system which is badged Smart-UPS C-1500-rack mountable and with have either on the reverse, it is machine normally aimed at networked entry-level protection and has modern features such as a liquid crystal display and green mode by which it can turn off facilities that do not require any power in normal use thus conserving energy until required.

• APC Smart-UPS C 1500 rack mountable battery
• SMC1500i-2UC battery

Not to be confused with the tower version of the same badge on the front, if that's what you have then there will be a link in the alternatives tab. The batteries on this page are for the 2u rack mountable version as you can see in the picture.

This system has many advanced features such as saving energy and LCD as mentioned above that squeeze into a rack-mountable 2U high case, the expected life of batteries in such a machine is between 3-5 years and the temperature-controlled charging circuit certainly helps to achieve this, the temperature is normally the biggest issue in battery life, in an ideal world you would be sitting your interruptible power supply in a dust-free climate-controlled environment, which you might have if you represent multinational financial cooperation if you are part of the rest of the real world though you may not. You can still help though, try to keep the room cool with plenty of ventilation and room around the vents to breathe, also you will note that dust will build around the vents, clear with a vacuum as that dust will find its way on the surface area inside, on the fan blades and so on, reducing the efficiency of their cooling effect, this will in time lead to shorter battery life.

The batteries are sealed lead acid valve-regulated or VRLA, they will not leak and can be mounted on the side so suitable for rack or tower UPS systems, they are also not-hazardous so safe to use in hospitals and data centres as well as of the home office.

There are four batteries in this set as would be required for the APC Smart-UPS SMC1500i-2UC, the size of each one is:
Length - 151mm
Width - 65mm
Height - 94mm
Chemistry type is VRLA, AGM, Pb, recyclable, 12v 7Ah