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Testing the battery with a 10A load, the battery quickly dropped to 11.6V which the UPS would consider to be 0% left!

Solution

Two items were identified:

• I was trying to pull more amperage than the replacement LiFePO4 battery would support. (Max 10A@12V or 1A@120V). Reduced number of protected devices on UPS.
• Battery/UPS could be reset by using the Powerchute software. Marked the battery as replaced and ran a quick battery test.

Configuring the UPS

List Commands

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I just got my problem solved and very excited. Here are the steps i have taken:

1. Uninstalled APC PowerChute Personal Edition Version 2.2 downloaded from the site.
2. Managed to get hold of my previous APC PowerChute Personal Edition Version 1.3.1 for Windows 98/Me/2000/2003/XP that shipped with the UPS.
3. After the installation, I found the following option under Monitor System>Run Self Test:
To Help PowerChute to keep track of battery life, please click HERE when you replace battery on clicking it the following popup appeared Are you sure that you want to update your battery's replacement date now. On clicking, it instantly reported the estimated battery time as 45 Min!!!!.

Reseting 

To do this, power down all equipment attached to the battery outlets.

Then reboot the Back-UPS ES by turning it off then count to 5 and power it back on.

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I couldn't find anyway to do this.

Teardown

https://www.youtube.com/watch?v=6UerOTuV6R4

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