Strange SUA3000XL behavior

[Anonymous user]

I have an SUA3000XL with two external battery packs (SUA48XLBP).  All the units are about 10 years old.  In the last couple of months, its ability to hold a sufficient charge diminished greatly, so I replaced all 10 batteries.  However, even after giving the batteries sufficient time to charge, self tests or the slightest under/over voltage event instantly takes the unit from a 100% charge to about 20%.  The battery charge indicator goes from five steady bars to one blinking bar.  At a 100% charge, PowerChute says that there are only 6-9 minutes of remaining runtime; at 20%, 1 minute.  This is despite the load only being at 16% of capacity (~42 Amps).  Years ago, I could get about 3 hours of runtime on that same load.  Recharging from 20% to 100% only takes 30-60 minutes, which is obviously much shorter than it should be.

I've verified that the Total Battery Packs value in PoweChute is still 2.  I ran Runtime Calibration from PowerChute but it hasn't helped.  Yes, I know that the proper way to calibrate an SUA3000XL is to pull its plug, but I don't have enough equipment connected to it to generate 30%+ load.  Besides, even without calibration, I wouldn't expect the unit to show such abysmal runtime nor have such a quick charge time.

Does anyone have any ideas?

[BillP]

Hi Steve,

The run-time calibration test as you mentioned requires at least 30% load to produce effective results. It would be advisable that you take the UPS to a authorised service centre who can recalibrate the unit via the serial interface. At the same time would be a good idea for them to open the UPS and check the internal components for aging and wear since the unit is 10 years old. The relays and capacitors could potentially require replacement. I would not advise you to open the unit UPS yourself unless you are qualified to do so as there are potentially dangerous or lethal voltages present.

If you do not have the option of a service centre available you can do some reading of the serial protocol which has been released by APC in the link below:

https://www.apc.com/shop/nz/en/products/UPS-Link-Protocol-Language-Clicking-Download-confirms-you-ag...

Additionally you will need to reset the battery constants manually for which the various UPS model constant can be found in the link below, you just need to look at your actual UPS model number.

http://www.apcupsd.com/manual/manual.html#resetting-the-ups-battery-constant

NB. You must use a APC serial cable originally supplied with the UPS, the part numbers are 940-0024 or 940-1524 which can be seen on the DB9 connector.

Please take care when doing anything via the serial interface since some of the commands can render the UPS inoperable.

[Brad_C]

On 16/10/2020 1:02 AM, Steve said:

Does anyone have any ideas?

Use a fan heater, halogen work lights, a standard resistive hair dryer. Get creative. I calibrated an SUA3000 last year with a 1200W fan heater load (it was a standard $15 2.4kw fan heater on half heat).

It would be a good idea to reset the battery constant via serial interface as described above, then do the runtime calibration. If the UPS has an NMC in it you'll need to remove that to get the serial interface into programming mode. Manually winding up the battery constant before doing the calibration generally gets an easier and better result. There have been occasions where a calibration with a very low constant hasn't worked.

On 16/10/2020 1:02 AM, Steve said:

Besides, even without calibration, I wouldn't expect the unit to show such abysmal runtime nor have such a quick charge time.

Does it actually have abysmal runtime, or does it just think it does? If you pull the mains does it actually die after 10 minutes or does it complain it's going to die and go for hours. A duff calibration will do that as it's still programmed to think it has severely compromised batteries. You *need* to do a proper runtime calibration to re-set it's assessment of the battery capacity.

[Anonymous user]

It's a good thing I rarely throw anything out.  I dug through my old boxes and found the serial cable that came with the unit, and an old DB-9 to USB adapter.  😄

I've queried the unit for model and version information, and this is what I got.

Ctrl-A: Smart-UPS 3000 XL
V: FWD
b: 691.19.D
0 (zero): 0C

According to the protocol specification, "F" means it's a Smart-UPS 450, but I have a 3000 XL.  Shouldn't that be an "O"?

The closest model name to mine that I could find in the table in the APCUPSD manual that you linked is "SUA3000RMXLI3U".  I'm not sure what that means--is that applicable to SUA3000 models that end in any of those characters?  In addition, it has "x"es in both the Hex and Firmware columns.  I'm not sure if that means that those values are irrelevant or if they're not known.

I find it odd that the "0" command, which displays the battery constant, is so low (0C) compared to the values I see in the "0" column in the table.  (The lowest one I see is "70".)  Is this indicative of anything?

[Anonymous user]

I haven't needed a hair dryer in years 😛, so the closest thing I have is a heat gun, but I'm not going to leave that running for a long time.  I've got a friend with a bunch of stuff in his garage.  Maybe he has something I can use.

As for its run time, it really is abysmal.  If I force it off of line power, it lasts all of two or three minutes at 16% load before totally powering off--the unit goes dead, with no lights on at all.  About five minutes later, it comes back to life.  With ten battery packs total (two in the main unit and four in each of the side units), which have been charging for a week, this is comically low run time.

[Brad_C]

On 17/10/2020 2:49 PM, Steve said:

0 (zero): 0C

On 17/10/2020 2:49 PM, Steve said:

I find it odd that the "0" command, which displays the battery constant, is so low (0C) compared to the values I see in the "0" column in the table.  (The lowest one I see is "70".)  Is this indicative of anything?

Yep, it's indicative of your last set of batteries being completely shagged. A good place to start is a similar UPS that uses the same batteries internally. Does the 3U use the same RBC number as your standard tower? If so, use that as the battery constant. You just want it close, the calibration will set it correctly.

As for load, I think from memory I ran the fan heater for just over 2 hours. It warmed things up a bit, but when you need a solid load it doesn't really matter what the load is, it all ends up as heat.

A heat gun would certainly do the job.

[Anonymous user]

On 10/17/2020 7:25 AM, Brad said:

Does the 3U use the same RBC number as your standard tower?

No.  The 3U takes a slide-in metal cartridge whereas the plain XL takes exposed battery packs.  Both RBCs have the same output voltages but different volt-amp-hour capacities (864 for the 3U vs. 816 for the XL).

Out of the entire list in the user manual, there are only two models that take the same RBC as my SUA3000XL--the SUA2200I and SUA2200XLI.  The I and XLI have very different battery constants:  B3 for the I and 7F for the XLI.  I'm not sure if either are applicable to my SUA3000XL.

Is doing a calibration sufficient to bring sanity back to my unit or do I need to change the constant to something more reasonable beforehand?

[Brad_C]

On 18/10/2020 5:15 AM, Steve said:

Is doing a calibration sufficient to bring sanity back to my unit or do I need to change the constant to something more reasonable beforehand?

Maybe. There have been plenty of cases of people going "I did a calibration and it's still wrong" when coming from a point of really dead batteries. That's why APC have the "serial key" they send out in the USA to reset the battery constant.

Personally I set it to something reasonable and then do the cal.

If you do a cal first and it doesn't work, then you are going to have to tweak the constant then do a cal again. I prefer just to get it right the first time.

[BillP · Accepted solution]

Hi Steve

The values I have for that model are:

                         4     5      6     0

SUA3000XLI   0A   B5   0E   93

Yours might be slightly different since you have a local unit whereas we deal with the international units. You should also be fine to adjust that any value between 7F or 93 since the value will decrease over time as the unit runs on battery. 

The other methods as some people have mentioned should also work by adding a heater load to get past the 30% mark and then perform a run-time calibrations test.

A simple exaltation of the values is that they are points on a battery discharge curve. You can look up what a battery discharge curve looks like and imagine the four point at different intervals.

[Anonymous user]

On 10/17/2020 10:45 PM, Llewellyn said:

The values I have for that model are:

                         4     5      6     0

SUA3000XLI   0A   B5   0E   93

Yours might be slightly different since you have a local unit whereas we deal with the international units. You should also be fine to adjust that any value between 7F or 93 since the value will decrease over time as the unit runs on battery. 

You were right!  I initially set the value of the 0 register to BC or something like that, and the unit reported a lot more run time than I expected (6+ hours instead of around 3 hours).  Today, I finally found enough old computers and laptops that when I plugged them all in I was able to get about a 35% load.  After pulling the plug and letting it discharge completely, the new value in the 0 register was 93.  So 93 was right all along.  🙂

Thanks again to everyone who responded.  I couldn't have done this without you.