Power from UPS goes out, even when house power stays on.

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M

mm

I hope this a good ng for this question:

Power from UPS goes out, even when house power stays on.

There was no power failure in the house, but the red light on the UPS
kept going on and off, while the green light went off and on, every 5
or 10 seconds, and the computer kept rebooting.

The battery is very old, but I would think even if the battery were
dead or missing, the UPS would put out good power if there were no
power failure in the house. So maybe the whole UPS is bad.

Should I buy a new lead acid battery, or asssume the UPS must be bad
and buy another one of those?

Thaks a lot.
 
mm said:
I hope this a good ng for this question:

Power from UPS goes out, even when house power stays on.

There was no power failure in the house, but the red light on the UPS
kept going on and off, while the green light went off and on, every 5
or 10 seconds, and the computer kept rebooting.

The battery is very old, but I would think even if the battery were
dead or missing, the UPS would put out good power if there were no
power failure in the house. So maybe the whole UPS is bad.

Should I buy a new lead acid battery, or asssume the UPS must be bad
and buy another one of those?
Click to expand...

Not if the battery were used as a large capacitor for filtering. Time
to crack open the case, get the battery number, and check with
BatteriesPlus if they have a replacement (which will probably be a lot
cheaper than getting one from the UPS manufacturer).

How old is "old"? Expect them to die after 5-6 years. I'm guessing
it's a gel battery instead of sulfuric acid (lead-acid).
 
mm said:
I hope this a good ng for this question:

Power from UPS goes out, even when house power stays on.

There was no power failure in the house, but the red light on the UPS
kept going on and off, while the green light went off and on, every 5
or 10 seconds, and the computer kept rebooting.

The battery is very old, but I would think even if the battery were
dead or missing, the UPS would put out good power if there were no
power failure in the house. So maybe the whole UPS is bad.

Should I buy a new lead acid battery, or asssume the UPS must be bad
and buy another one of those?

Thaks a lot.
Click to expand...


Part of my job is servicing commercial UPS's
and I do have experience with the smaller , "home" variety too.

You are right. If the battery is dead, the UPS will generally not cut
out unless the power does.

Good chance you'd be wasting money if you bought a new battery.


First I'd confirm that your outlet is good (not intermittent).

Also, disconnect the battery and (assuming it's 12v) connect a 12v
automotive light bulb to it. If it lights normally for at least a few
minutes then though the battery may be old and weak...it's at least good
enough not to be the source of a UPS malfunction under power
 
Part of my job is servicing commercial UPS's
and I do have experience with the smaller , "home" variety too.

You are right. If the battery is dead, the UPS will generally not cut
out unless the power does.

Good chance you'd be wasting money if you bought a new battery.


First I'd confirm that your outlet is good (not intermittent).
Click to expand...

I did that. Plugged the 2 things plugged into the UPS into the same
place the UPS had been plugged in, and all works fine.
Also, disconnect the battery and (assuming it's 12v) connect a 12v
automotive light bulb to it. If it lights normally for at least a few
minutes then though the battery may be old and weak...it's at least good
enough not to be the source of a UPS malfunction under power
Click to expand...

Okay. I'll check it over the weekend.

Thanks.
 
Not if the battery were used as a large capacitor for filtering. Time
to crack open the case, get the battery number, and check with
BatteriesPlus if they have a replacement (which will probably be a lot
cheaper than getting one from the UPS manufacturer).

How old is "old"? Expect them to die after 5-6 years. I'm guessing
Click to expand...

I lose track but it might be 10 years old.

Still, it had enough in it just 2 months ago to give me 5 or 6 seconds
at least, which is enough to say cntl-S and save my work. (I never
leave a window without saving what is in that window, so the only
thing I need to save is in the open windows.)
it's a gel battery instead of sulfuric acid (lead-acid).
Click to expand...

Maybe. Can't remember. :)

Thanks.
 
mm said:
I lose track but it might be 10 years old.
Click to expand...

How long before you have to replace your car's battery? And that one
is huge compared to the one inside your UPS.
 
VanguardLH said:
Not if the battery were used as a large capacitor for filtering. Time
to crack open the case, get the battery number, and check with
BatteriesPlus if they have a replacement (which will probably be a lot
cheaper than getting one from the UPS manufacturer).
Click to expand...

Why are you recommending such an expensive supplier? I've gotten
replacement batteries from fire alarm/security system supply houses
for much less.
How old is "old"? Expect them to die after 5-6 years. I'm guessing
it's a gel battery instead of sulfuric acid (lead-acid).
Click to expand...

Why can't a gel battery use lead & sulfuric acid chemistry?
 
mm said:
Power from UPS goes out, even when house power stays on.

There was no power failure in the house, but the red light on the UPS
kept going on and off, while the green light went off and on, every 5
or 10 seconds, and the computer kept rebooting.

The battery is very old, but I would think even if the battery were
dead or missing, the UPS would put out good power if there were no
power failure in the house. So maybe the whole UPS is bad.

Should I buy a new lead acid battery, or asssume the UPS must be bad
and buy another one of those?
Click to expand...

The easiest way to find out is by testing it with a good battery of
the same type of chemistry (lead & sulfuric acid, just like car an
golf cart batteries) and voltage (your UPS likely uses a 6V battery,
not 12V like your car. If that's the case, do NOT connect the car
battery to it). If the mechanical fit is different and you have to
wire it in, be absolutely certain to get the polarities straight and
avoid shorts, and make the connections and disconnections only while
the UPS is unplugged from the AC.

Another thing to try is remove the battery and measure its voltage
(any DIGITAL multimeter, even a $3 one, is fine). If a 6V battery
measures about 4V or less or a 12V battery measures 10V or less, it's
a dud. Each cell in a lead acid battery contributes a bit more than
2V to the total. Assuming the battery measures OK, measure again with
a load, like a 12V incandescent automotive brake light bulb. It
should stay above 5V for a 6V battery, above 10V for a 12V battery.

The only other testing you can do is unplug the AC, disconnect the
battery (IMPORTANT: UPS circuits can present electrocution hazards
even without the AC plugged in), and check for broken solder
connections (hairline cracks may require a magnifying glass to see),
shorted transistors or diodes, or bad capacitors (latter may test fine
with an ohm/voltage/capacitance meter and fail only with an ESR test).

Sometimes Staples, Office Depot, and OfficeMax have close-outs on
backup supplies. I saw some 350-500VA CyberPower a few weeks ago for
$25.
 
mm said:
I did that. Plugged the 2 things plugged into the UPS into the same
place the UPS had been plugged in, and all works fine.

Okay. I'll check it over the weekend.

Thanks.
Click to expand...



I saw elsewhere that the battery is ten years old

so it's definitely going to be bad...

but if it can light a bulb for a few minutes that means it has just a
tiny bit of capacity left.

So, unless you can test the unit with an other battery (maybe a car
battery?) It would be a gamble to replace it.
 
Why can't a gel battery use lead & sulfuric acid chemistry?
Click to expand...

It does.

It's just the liquid acid that is gelled, making it less susceptible to
spilling and spray/frothing.
 
mm said:
I hope this a good ng for this question:

Power from UPS goes out, even when house power stays on.

There was no power failure in the house, but the red light on the UPS
kept going on and off, while the green light went off and on, every 5
or 10 seconds, and the computer kept rebooting.

The battery is very old, but I would think even if the battery were
dead or missing, the UPS would put out good power if there were no
power failure in the house. So maybe the whole UPS is bad.

Should I buy a new lead acid battery, or asssume the UPS must be bad
and buy another one of those?

Thaks a lot.
Click to expand...



Have found most of the SOHO UPS's turn off when the battery will no longer
hold a charge.
10 years is is way over the average life for SOHO UPS battery's.

= buy a new battery.

Best
Paul.
 
Part of my job is servicing commercial UPS's
and I do have experience with the smaller , "home" variety too.

You are right. If the battery is dead, the UPS will generally not cut
out unless the power does.

Good chance you'd be wasting money if you bought a new battery.


First I'd confirm that your outlet is good (not intermittent).

Also, disconnect the battery and (assuming it's 12v) connect a 12v
automotive light bulb to it. If it lights normally for at least a few
minutes then though the battery may be old and weak...it's at least good
enough not to be the source of a UPS malfunction under power
Click to expand...

It turns out that the battery was good, but the UPS was no good. I
bought it used 5 or 10 years ago, so I'm not complaining.

Thanks.
 
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