Our company acquired another company a couple years ago. They have a server rack with a heavy duty UPS mounted in the rack. Recently, the device starting beeping and I assume batteries are dead. it is at a remote site and the local users are not able to see the serial number on the back. They have sent me photos that identifies it as an APC3000XL, but on top of the machine it displays 5 possible models. Can anyone identify from the photos exactly what device I might have and which batteries I should order? I am assuming drawers will pull out from the device and an array of batteries will need to be replaced. I have attached the best photos I have.