On 02/02/2009 05:34 PM, Warren Post sent:
I just replaced the battery in my UPS, and notice that the old one was
swollen and hard to remove. Searching this NG and elsewhere on the net, I
see this means that the battery had reached the end of its life some time
ago and should have been replaced sooner. Okay, replacing the battery
when it reaches the end of its life cycle instead of waiting until it
obviously fails is fine by me.

So how do I know when to replace a UPS battery? This particular UPS has
no self test feature and no com port with which to communicate with the
computer, and I don't want to toss perfectly working equipment into the
landfill just because it lacks bells and whistles to make my life a
little easier.

Hello Warren:

In a previous life, I oversaw many systems with UPS protection. Some of
the UPS systems helped with super mission critical applications. As is
hinted in your post, your UPS(s) are not as fully featured as many are
today. You might wish to consider slowly moving your current UPS
system(s) to less critical applications while replacing them with higher
tech models. Some manufacturers had been offering a trade-up program at
one time.

Most manufacturers will offer a load chart to predict the rundown time
of a new/quality battery under various load conditions. While
maintaining some of my UPS systems, I obtained a short heavy-duty
extension cord and I stripped off the outer insulation covering to reach
the individual wires for ease of current measurements. I used various
combinations of output adjustable space heaters and heavy-duty soldering
irons to establish differing power testing loads. I found the
predictive charts rather accurate.

Some UPS manufacturers do seem to overcharge their batteries as has been
reported in other threads. This in combination with various repeated
full discharge cycles will limit the overall battery life of anything.
Where a UPS was lightly loaded and not driven to battery exhaustion more
than a few times, I'd see batteries last for five years. Less favorable
conditions gave us sometimes just three years. Worst case I saw was
about two years battery life.

Where a situation warranted it, I've mounted muffin fans directly to UPS
exhaust ports to improve air flow in rack mount configurations. Ugly
but effective.

Your reported observation would lead me to believe that your UPS is
overcharging its battery. I believe this is not easily dealt with and
probably not correctable without modifications.

HTH

Pete
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1PW @?6A62?FEH9E=6o2@=]4@ [r4o7t]