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APC Smart UPS 600 Problem

I

Isi

Jan 1, 1970
0
The APC Smart UPS 600VA (AP600) had dead batteries, and I replaced them with
new ones. After replacing the batteries, I tested the unit with a 100W load
(light bulb), and it switches to battery mode properly with cut AC. Once the
load is increased to 300W (halogen bulb again) it reports low battery, even
when the AC power is present. The unit properly switches to battery power on
AC loss, but low battery is still on. Once the load is decreased, the low
battery goes off instantly and it works normally. I checked the battery
voltage and I found 26V (2X13V) with 300W load (or no load) and AC power,
and 23.5V (2X11.75V) when operated on battery with cut AC and 300W load,
which seems OK. Is a recalibration required after replacing the batteries?
Thanks in advance.

Istvan
icsaki at hotmail dot com
 
J

Johnboy

Jan 1, 1970
0
I would check the batteries real carefully. I have found even new SLA
batteries are bad from the get go. I would guess old stock. They must
hold about 12.9 to 13.0 under rated amp load. If they drop to your
measured 11.75, the battery has bad cells. Fully charged brand new
ones are 13.0 after a 24 hour rest and will not drop volts under the
rated load.
 
J

Jerry G.

Jan 1, 1970
0
You must leave the batteries charging for a minimum of 12 hours when new. If
they are still indicating weak, they may be have been in stock too long.

You must be very sure of the source from where you buy your batteries.

--

Jerry G.
==========================


The APC Smart UPS 600VA (AP600) had dead batteries, and I replaced them with
new ones. After replacing the batteries, I tested the unit with a 100W load
(light bulb), and it switches to battery mode properly with cut AC. Once the
load is increased to 300W (halogen bulb again) it reports low battery, even
when the AC power is present. The unit properly switches to battery power on
AC loss, but low battery is still on. Once the load is decreased, the low
battery goes off instantly and it works normally. I checked the battery
voltage and I found 26V (2X13V) with 300W load (or no load) and AC power,
and 23.5V (2X11.75V) when operated on battery with cut AC and 300W load,
which seems OK. Is a recalibration required after replacing the batteries?
Thanks in advance.

Istvan
icsaki at hotmail dot com
 
I

Isi

Jan 1, 1970
0
Thanks for the reply.
What I was trying to say is that is turns on low battery when I plug in the
300W bulb. The unit is still on AC power, the battery is at 13V(no load).
Low battery???? If I cut now the AC, the load will be transferred to battery
(~15A) and the battery holds at 11.75V. And yes, the batteries are fully
charged (operating for more than a week), and I have load-tested them to
check the capacity - they are good.

I really appreciate any suggestions.
Istvan
 
I

Isi

Jan 1, 1970
0
I measured the voltages again and I have to make a small correction:
The batteries have 13.4V out of the circuit (no load) and 13.8V in the unit,
when operated from AC power.
When the 300W load is connected, the battery has still 13.8V (AC power) and
the low battery LED comes on.
Thanks.
 
B

Bwibble

Jan 1, 1970
0
To calibrate :-

Using software on PC if you have it put a 33% load on the ups,
or as close as you can get.

Turn everything off then disconnect the serial comms lead to the pc
and also disconnect the mains into the UPS.

Turn on the ups with the load and run the batteries down until the
UPS switches off.

Re-connect the ups mains and charge the batteries then remove
mains and discharge again, and again recharge, that should recalibrate
the new batteries.
 
G

Gerard Bok

Jan 1, 1970
0
The APC Smart UPS 600VA (AP600) had dead batteries, and I replaced them with
new ones. After replacing the batteries, I tested the unit with a 100W load
(light bulb), and it switches to battery mode properly with cut AC. Once the
load is increased to 300W (halogen bulb again) it reports low battery, even
when the AC power is present. The unit properly switches to battery power on
AC loss, but low battery is still on. Once the load is decreased, the low
battery goes off instantly and it works normally. I checked the battery
voltage and I found 26V (2X13V) with 300W load (or no load) and AC power,
and 23.5V (2X11.75V) when operated on battery with cut AC and 300W load,
which seems OK. Is a recalibration required after replacing the batteries?

Are you sure that the meaning of the indication is 'weak battery'
exclusively ?
I could imagine a more general 'attention required' indicator,
which would be triggered by both 'weak battery' and 'execessive
load connected' situations.
Your opservations seem to support this.

(If it is a really smart UPS, it could sense that it probably
would not be able to start your 300 Watt halogen load :)
 
I

Isi

Jan 1, 1970
0
Thanks for the reply.
I think the procedure you described below will rather "re-form" the
batteries after storage. The battery capacity may be updated by this (to
reflect proper "time remaining" based on load). The low battery threshhold
voltage will not be affected (at least I don't see how). The problem is that
this treshhold voltage is changing based on load, and it shouldn't...
 
I

Isi

Jan 1, 1970
0
Does anybody have a schematic for this unit by any chance?
The model number is "Smart-UPS 600" or "AP600".
Thanks in advance.
 
N

Nelson

Jan 1, 1970
0
Does anybody have a schematic for this unit by any chance?
The model number is "Smart-UPS 600" or "AP600".
Thanks in advance.

I have a Smart-UPS 1600 and I suspect the controler is the same. I was
unable to find any schematics for it... APS wants you to ship it to one
of their repair shops. That would cost more than a new unit, which I
guess is the plan :)

In my case the problem is that it reverts to battery a couple of
seconds after turning on even though it is plugged in to the AC and the
AC is within spec. A pity... you know it has to be something simple.
I started to make a schematic myself but there are too many
proprietary/unknown chips to figure it out (for me at least)

Let me know if you find one.
 
B

Bennett Price

Jan 1, 1970
0
When you first turn the UPS on it runs a self test during which it
briefly runs on battery. (You can't turn it on at all if AC is not
present). The self-test is normal. Or do you mean that it goes to
battery after you turn it on and never reverts backs to normal AC operation?
 
N

Nelson

Jan 1, 1970
0
When you first turn the UPS on it runs a self test during which it
briefly runs on battery. (You can't turn it on at all if AC is not
present). The self-test is normal. Or do you mean that it goes to
battery after you turn it on and never reverts backs to normal AC operation?

It runs the self test, and either reverts to battery immediately or
after a few minutes. Somehow it is thinking the AC has failed when it
hasn't.

Nelson
 
I

Isi

Jan 1, 1970
0
Just for the record: doing a "Run Time Calibration" from the PowerChute
software fixed the problem. Simple and effective solution. Apparently the
UPS stored some data about the old batteries, and a 300W load could have
been hold for less than 2 minutes with the old batteries. The 2 minute
barrier before shutdown is the low-battery threshhold, so it turned on the
low-battery signal for the 300W load.
Doing the run time calibration with the new batteries cleared the old
battery data, so everything is back to normal.

Thanks for all who helped.
 
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