Battery not holding full charge - Why?

[Anonymous user]

Greetings.

I have an APC Back-UPS XS 1200 (Serial Number JB0747005944, Firmware v831.E6.D) that has been having an issue that I need some help with.

Over the last few months, I have noticed that the battery level has been varying between 91 to 98 percent charged, when it should have been at 100 percent charge, as the PowerChute software reported no recent events for at least the past several days. The charge level does eventually return to 100 percent after varying amounts of time, and it did pass a manual self-test on 6/12/2010, but I am wondering if my unit has an issue.

A bit more background info that may be helpful:

- It's a rebranded APC unit, branded as an Office Depot Ativa unit
- It was purchased new on Black Friday 2008 (11/28/2008) ($50 AR FTW!)
- It's been well-maintained (Cool environment most of the time, no more than a 200 watt load, often less, never discharged below 50%, etc.)

Thanks!

[Anonymous user]

In response to your question, the first six digits/characters of my unit's serial number are JB0747. See post #1 for the complete serial number.

[Anonymous user]

I have not yet received a response to post #3 of this thread.

Anyone?

Bueller?.. Bueller?

[BillP]

this does not seem like that big of a concern functionality wise - meaning nothing is majorly wrong. the unit may need to be calibrated.

my concern would be - is it providing the correct amount of battery back up time it should? like it used to?

you could try discharging the unit completely, with no USB cables or software attached with a non critical load and then let it charge back up, maybe while its turned off so that the battery won't drain during recharge and see what it says when you reconnect everything afterwards. i would let it charge for a full 24-48 hours if you let it discharge completely.

this will waste a discharge on the battery though and the battery is starting to get older - your serial number is from late 2007 and batteries generally last 3-5 years based on usage. it may not be worth it to see if the battery percentage jumps up a few percent on your software.

its up to you - from my own personal opinion, it is most likely just cosmetic and more of an annoyance than a failure to be concerned with but you could try the steps above to see if it recalibrates and reaches 100%.

hope that helps 😕

[Anonymous user]

Thanks for your reply. I marked it as helpful.

The answer to your question of "Is it providing the correct amount of battery backup time it should" is "I think so, but I'm not sure." I have the PowerChute software configured to shut down my PC if the transfer to battery is longer than 5 minutes, to preserve the battery. With 3 exceptions (1 utility company transformer failure, 2 planned utility outages to repair that transformer), it has never reached the 5 minute mark during battery operation.

Just before I replied to your message, there was a power failure that lasted 35 seconds, according to PowerChute. Prior to that power incident, the battery was showing a 100% charge, and after it, the battery was showing a 90% charge. The battery dipped to 89% (even though its status showed as 'Charging') and is now increasing as expected. The average load during the outage and extending to right now is shown as about 115 watts, occasionally spiking to 122 watts. Heavy gaming causes the usage to spike to about 155 watts. (Core 2 Quad Q6600 @ 2.4 Ghz, 2 GB DDR2, dual Nvidia 9400GT graphics cards, dual 3.5" hard drives, 1 5.25" DVD writer, 1 17" LCD monitor, a set of desktop stereo speakers, an amplified TV antenna, and a smartphone charging via USB from the PC)

Is that normal?

As for your suggestion of a complete discharge and recharge of the UPS battery, I have no desire to needlessly strain the battery. It is my understanding that discharging a (deep cycle?) lead-acid battery below the 50% mark shortens its service life markedly, and the less they are discharged, the longer they last, assuming that they are promptly and completely recharged. (I use a power wheelchair daily, which runs on 2 12V deep-cycle lead acid batteries, my battery knowledge comes from maintaining my chair's batteries.)

[Anonymous user · Accepted solution]

Greetings.

I have an APC Back-UPS XS 1200 (Serial Number JB0747005944, Firmware v831.E6.D) that has been having an issue that I need some help with.

Over the last few months, I have noticed that the battery level has been varying between 91 to 98 percent charged, when it should have been at 100 percent charge, as the PowerChute software reported no recent events for at least the past several days. The charge level does eventually return to 100 percent after varying amounts of time, and it did pass a manual self-test on 6/12/2010, but I am wondering if my unit has an issue.

A bit more background info that may be helpful:

- It's a rebranded APC unit, branded as an Office Depot Ativa unit
- It was purchased new on Black Friday 2008 (11/28/2008) ($50 AR FTW!)
- It's been well-maintained (Cool environment most of the time, no more than a 200 watt load, often less, never discharged below 50%, etc.)

Thanks!