[HH] UPS batteries

[Tom Metro]

I had a UPS battery die today. I guess better today than tomorrow during
a potential power outage. I pulled the battery and confirmed it was
reading low - 10-something volts.

What bugs me is that the battery was last replaced in June 2009, so it
is just over 3 years by a bit. That's generally considered the minimum
lifespan for a SLA. It hasn't been particularly stressed. Only once
fully discharged, to my recollection.

The battery was a bit on the warm side when remove. It's possible the
charge circuit might have failed and isn't regulating the current properly.

According to my notes (an email complaint to the vendor), this battery
was part of an order that came poorly packed, and showed some physical
damage to the battery (bent terminals). It's possible it had some
internal damage that contributed to its short lifespan.

Another possibility is that the Universal Power Group manufactured
batteries, which is what has ended up being at the best price point the
last few times I've ordered replacement UPS batteries, just aren't up to
the same quality standards.

Anyone else noticed problems with Universal Power Group (UB) batteries?
Do you have a favorite battery vendor?


I've possibly had other problems with Universal Power Group batteries
ordered around that time. On that same 2009 order I bought a batch of 3
batteries to go into a larger UPS, and a month later ordered a pair of
batteries for another UPS. In both of these cases, the UPSs failed to
function correctly after the batteries were replaced.

I went as far as pulling the batteries and checking the voltage, which
was within the expected range. I had enough other functioning UPSs at
the time that I didn't dig any deeper, and just put the batteries aside
for future use.

But I was left feeling rather suspicious of the batteries. I could see
the electronics in one of the UPSs failing, but it seemed a bit more
than coincidental that both would be bad. (Each was taken out of service
at a different time. I believe both indicated a failed battery.)

I'll have to take a closer look at them someday. I'll charge the
batteries first, and monitor battery voltage and current to see if the
charger circuit is working properly.

(Has anyone else noticed that typical UPSs make it very difficult to
distinguish between a battery failure and an electronics failure? Once
the battery voltage drops below some threshold, most UPSs seem to act
flaky and the warning lights and power switch behavior becomes erratic.

I've seen this on several APC models, and I believe on some other brands
as well. When I first ran across this I thought he electronics were
fried, but tried a good battery anyway, and was surprised to see it
magically start to behave normally. Seems like a pretty stupid design.
Logically, the electronics should be powered by both the AC and the
battery through isolation diodes, and should operate normally, even with
no battery installed.)


I grabbed one of the batteries from the July 2009 order that happened to
be the same size as the small UPS uses, and the voltage checked out.
Theoretically you're supposed to charge SLAs about once every 3 months
to keep them in good condition, which I hadn't been doing. Given the
battery is already 3 years old and hasn't been properly stored, I guess
I shouldn't expect much life from it, but for the time being it is working.

 -Tom