Defective Battery

[Ian29]

I have an APC UPS ES700G which has been working well for 8 years, but during a recent power cut I noticed the battery discharged extremely quickly, it lasted about 4 or 5 minutes whereas it used to give me 20 minutes with the same devices connected.

Time to replace the battery I thought, so ordered a new one from the APC shop on Amazon, it arrived the next day.  Installed, it, charged it overnight, then tested it by turning off the power.  The performance is no better than the one it replaced.  I then charged the battery again and tested it with no external loads.  Even in this scenario where it is only powering the internal circuitry of the UPS it lost 50% charge in 5 minutes.

Have I been sold a dud battery or does this indicate a problem with the UPS itself, and how do I figure that out? 

I have to add, the new battery does not look "new", the label is old and faded, it looks like it's been around for a while.

[Teken]

Complete the action items as outlined in this related thread for RBC Replacement and report the outcome:

https://community.se.com/t5/APC-UPS-for-Home-and-Office-Forum/XS-1300-with-new-battery-battery-just-...

Questions Ask . . . 👍

[Ian29]

Thanks for your reply.  I am more confused now though, none of the options you mention can be found in the PowerChute software I had so I downloaded the latest version (PCSS) and installed that.  Now I have an option to set the battery installation date, but there is nothing about Self Test or Calibration.  Also, none of this is mentioned in the installation instructions that came with the battery, that was just, take out the old, install the new, switch the unit back on.  I only left it to charge overnight because that was in the original installation instructions for the UPS. 

I have now put the old battery back in and after testing I concluded it performs better than the new battery (discharges slightly more slowly with zero external load).  The new battery will be returned.

[JamesOConnor · Accepted solution]

You are likely dealing with two separate issues here: a degraded UPS and a battery that sat on the shelf too long.

First, the battery you received is almost certainly "New Old Stock" (NOS). Sealed lead-acid batteries permanently degrade if they sit in a warehouse for a year or more without a maintenance charge. The faded label and the fact that it dropped 50% in five minutes under no load strongly point to a battery that is already dead, despite being sold as new. I recommend returning it to Amazon as defective.

Second, your UPS is eight years old. Consumer UPS units typically have a reliable service life of about 3 to 5 years. Over time, the constant heat dries out the internal capacitors, which often causes the battery charging circuit to fail. Even with a perfectly healthy battery, an aging UPS can fail to charge it properly or misreport the battery's health.

If you want to test the UPS, you can use a digital multimeter. Carefully measure the voltage across the battery terminals while the UPS is plugged into the wall. A healthy charging circuit should output between 13.5V and 13.8V. If it is lower than that, the UPS is no longer capable of charging.

Given the age of the unit, investing in another replacement battery carries a high risk of failure. Upgrading to a new UPS will be the most reliable way to protect your connected devices.

[Teken · Accepted solution]

You may initiate both action items manually if the feature isn’t present. The self test is automatically triggered upon first power up and 14 days later.

Self Test: You may manually initiate the same by pressing and holding the power button for 2 to 3 seconds until you hear two beeps or see the online LED begin to blink, then release the button. Thetest completes when the button changes back to a solid light.

Calibration: Insure the RBC is 100% charged and there is a minimum of 30% connected load or higher. Remove AC Mains from the wall outlet and let the system drain and shutdown.

Once complete reconnect AC Mains and allow the system to recharge the RBC to 100% SOC. This can take a minimum of 72 hours which is subject to the RBC health.

This procedure will teach the system the current health of the RBC and better reflect the operational runtime via Power Chute.

NOTE: The service life of the RBC is 2-5 years depending upon usage, temperature, and environmental conditions. The raw cell is designed to provide up to 260 cycles subject to the same caveats as above.

At eight years you’re on borrowed time and the RBC will fail without notice. A battery calibration must be done on a brand new RBC upon installation.

Performing a battery calibration on a marginal RBC will speed up the degradation of the cell. As such a battery calibration is only performed on an annual basis in an enterprise environment to validate the current state of health.

Well knowing this process will impact the overall service life of the RBC.

Questions Ask . . . 👍

[Ian29]

Thank you for all replies, the information provided is all very helpful. The battery has been returned and I ordered a new one.  The new battery looked like it was new, measured 12.9V and showed 98% charge when installed.  The unit is now working as it was before with 20 to 30 minutes runtime on a power outage.

One point to note, this UPS model does not seem to have a self-test option.  Holding the power button for a few seconds does nothing other than switch the power off.  It's not a problem, everything seems to be working well and voltage across the terminals while charging is 13.5 to 13.6V.