SMART-UPS 1500 doesn't failover to battery

[sdmguy]

I have had this unit for quite a while. It's been operating as expected until recently. The battery tests fine and the load is well below maximum, but I have a few machines plugged into the unit and when AC power fails, all of the machines plugged in lose power. It's as if the battery is not kicking in at all. Any thoughts? 

[Teken]

What do the data & event logs show when you disconnect power from the unit?!?

What is the installation date of the battery cartridge and serial number of the UPS?!?

[sdmguy]

Which data and event logs are you referring to? 

Installation date of battery shows as: Sept-2014

Serial # is: 3S1437X06009

[Teken]

If the above is true the battery cartridge is ten years old and EOL. The service life is rated for 2-5 years based on usage, temperature, and environmental conditions.

A simple test is removing AC power from the wall outlet to see if the unit continues to operate.

Based on your own personal experience it doesn’t and just shuts down. Remove the battery cartridge and measure the voltage depending upon which specific model you have it’s either a 24 / 48 VDC system. 

Both use 12 VDC cells wired in series / parallel. Unplug all the wires connecting the cells and measure the voltage on each individual cell and record / report them here.

Come back in 24~72 hours and measure / report back what voltage is seen on each cell. A healthy cell after removing the surface charge will be 12.8 - 12.90 VDC and will drop 0.01 - 0.1 volts.

If any cell drops by 0.5 ~ 1.XX VDC just in 72 hours it simply confirms the cell is dead. You can hook up any 12 VDC load to each cell to perform a dynamic test such as a light / fan.

You’ll quickly see it won’t power these loads very long if at all. The RBC can be found under the About tab in the LCD. You can purchase a replacement APC RBC cartridge or rebuild the pack yourself using HR rated cells such as CSB which are one of the OEM makers for APC.

LOGS: The event / data logs can be viewed from LCD / exported from Power Chute / NMC is present.