Does the Symmetra LX charge batteries while in Maintenance Bypass or even Control Panel Bypass?

[Anonymous user]

We had a recent power interruption event and our APC Symmetra was unable to service our Data Centre's need for backup power during the minor black-out (mere seconds). When troubleshooting the issue, we learned that the device was reporting battery faults in the remaining pool of 7 batteries still in the unit. Two batteries of the original nine had been removed in previous weeks due to overheating battery alerts. Unfortunately, we learned during this post power interruption troubleshooting that the UPS was in automated bypass, hence why interruption to the power feed didn't engage the battery system. Battery capacity was listed as 0% and both the soft Bypass was on and Provide Output Power was off. Changing these Control Panel switches restored power to our Data Centre to get our servers back up and running.

Note, both the Symmetra LX and its batteries are now 3 years old.

Now we are in battery replacement mode as well as post event troubleshooting and knowledge acquisition. Under advise by Tech Support, we placed the Maintenance Bypass into the On position (engaging Maintenance Bypass), and removed all of the remaining 6 batteries, and inserted a single new battery. After a few moments, the unit was able to indicate that the battery capacity was at about 25%, and then later in the day installed another new battery (these new batteries arrived in different courier shipments during the business day), now showed battery capacity at 43%. We left the unit in Maintenance Bypass overnight to see if the batteries would charge.

The next day we are showing 23% capacity in the two new batteries. What's going on?

[Anonymous user · Accepted solution]

Thanks, that explained the problem and the symptoms we saw.

We couldn't get enough Runtime Remaining with the two new batteries, because it was no longer charging the batteries (the two installed power modules were showing Off & OK), so we were forced to install one of the former 6 pulled batteries (none of these 6 had a heat problem) at a time, allowing for the unit to recognize the battery and calculate new Runtime Remaining values. Once all six were in again, together with the two new ones, we noted a Runtime value of 1hr 5min. We felt it would be then safe to come off of Maintenance Bypass to allow the Self-test to run, and Power modules to come back online.

This appeared to work, and the Power modules came back online (On & OK), and all 8 batteries report OK status, but the Self-Test has been running for 1hr 50min, and according to the Overview readings on UPS Network Management session, we are declining now to only 33 minutes of Runtime and Battery Capacity has dropped to 20%. Thirty minutes ago those were 47 minutes of Runtime and 28% Battery Capacity.

Why would the Self-Test take so long? In past months it ran for only a minute or so.