APC - battery disconnected reconnected

[GaryG_Accel]

How can I disable Green Mode for a few days on the SMT3000R2X145?

here's more info.

I saw a similar topic about constant battery disconnect cycling. I read that and tried the instructions. I have a related question.

I have a SMT3000R2X145.  Yes it is old.  Yes it is being replaced with a new APC, asap.

When I read one similar topic, I followed APC instructions on that topic.  I physically disconnected and reconnected and reseated the battery and connectors. That didn't solve the problem.

This will be solved when the new APC arrives in a few days.

The battery disconnection cycle has gotten worse.  (After I noticed this, it stopped after 30 minutes and was OK for over 24 hours. Now it is constant.)

From observation of the timing, this is related to or possibly caused by the APC going into Online (Green Mode).  I read a bit about the circuitry that does Green Mode.  That is interesting but we don't care about saving 10 watts or so.

I want to turn off Green Mode to see if that temporarily alleviates the problem, but I don't see that option on the PowerChute webgui nor on the front panel.

How can I disable Green Mode for a few days on the SMT3000R2X145?

Here's why I think Green Mode is the issue, the timing of these events.

it looks like Reconnect occurs when Green Mode is exited and Disconnect occurs when Green Mode is entered.

5/6/25	04:04:03	Battery Disconnected
5/6/25	04:04:02	Online (Green Mode) - Entered
5/6/25	04:03:45	Battery Reconnected
5/6/25	04:03:44	Online (Green Mode) - Exited
5/6/25	04:03:29	Online (Green Mode) - Entered
5/6/25	04:03:26	Battery Disconnected
5/6/25	04:03:11	Battery Reconnected
5/6/25	04:03:09	Online (Green Mode) - Exited
5/6/25	04:02:54	Online (Green Mode) - Entered
5/6/25	04:02:53	Battery Disconnected
5/6/25	04:02:35	Battery Reconnected
5/6/25	04:02:34	Online (Green Mode) - Exited
5/6/25	04:02:20	Online (Green Mode) - Entered
5/6/25	04:02:19	Battery Disconnected
5/6/25	04:02:01	Battery Reconnected
5/6/25	04:02:01	Online (Green Mode) - Exited
5/6/25	04:01:46	Battery Disconnected
5/6/25	04:01:46	Online (Green Mode) - Entered
5/6/25	04:01:28	Battery Reconnected
5/6/25	04:01:27	Online (Green Mode) - Exited

[Teken · Accepted solution]

If Green Mode is available it can be accessed through the LCD Menu once the Advanced View is enabled. If the system has an NMC installed with at least 6.5.X firmware installed (IF) present (Green Mode) can be enabled / disabled via: Configuration -> Power Settings.

NOTE: The UPS Firmware also plays an important roll in this option being present / not. Lastly, the sensitivity, upper / lower transfer voltage also impact how the system behaves. The sensitivity generally speaking impacts when the system will go into battery only mode. The upper and lower transfer voltage impact when the system will engage the AVR circuit.  

Questions Ask . . . 👍

[GaryG_Accel]

Don't have NMC.

Looked at LCD menu, Advanced is On, Configuration doesn't show Green Mode option.

Sensitivity = Normal.  Low = 106v High = 127v

I'm slightly irritated that Green Mode is automatic and can't be turned off from the WebGUI of PowerChute and not even off from the LCD panel.

The unit is also not smart enough to stop attempting to switch to Green Mode (which I understand is slower or lighter charging that uses less energy, since the battery is fully charged (when it shows as connected).

What is "Green Mode" on a Smart-UPS, Smart UPS On-Line, or Smart-UPS Ultra? - APC USA 

Green Mode utilizes relays that bypass certain internal components of the UPS

switchover can take up to 10 ms
I'm fairly convinced it's the Green Mode circuit switch that is triggering the battery disconnect every 30 seconds or less.  So the unit is faulty and a new one is on the way.

Electrical Engineer gives reasons why one might want to turn off Green Mode (The Switch Mode Power Supply (SMPS) circuit has failed and you want to run the UPS without it.)

How To: Disable Green Mode on APC Smart-UPS SMT series - Page 1 

There's a check box on the NMC (which I don't have) interface, but he says that doesn't disable Green Mode.

But anyone who's tried it will know it doesn't actually work! At least not on units of the vintage I have. There is also no front panel setting for green mode on any of my units. 

Yet I can see Green Mode being activated in the Logs.

His solution was to (a) connect the serial port (b) dump the firmware to study using a 8051 disassembler program (c) write 0x13 to the main processor via the internal serial port, to be stored in EEPROM.

This is beyond me, but it's interesting. It's also interesting that the owner has to hack the UPS to turn off Energy Efficiency.  I can turn that off on my computer without issue.

After a great deal of head scratching and learning how assembly code actually works, I believe I struck gold. I knew that entering programming mode (part of the APC Smart Protocol, achieved by sending two 1s, about one second apart) causes the UPS to exit green mode and not re-enter it until leaving programming mode. I therefore reverse engineered that small part of the firmware, and found that a specific memory location was being checked in parallel with that check of programming mode which I believed to be disabling green mode. That specific memory location is only ever written to if the device reads ASCII code 0x13, i.e. CTRL-S, on the serial port, which toggles it between zero and one. It was a long shot, but the value of that parameter appeared to be causing a change in program execution that looked about right, so of course I tried it.

Testing
Upon sending 0x13 to the main processor via the internal serial port, once in Smart mode (Y->SM), I got responses of '01' and then '00' and then '01' again - i.e. toggling the value. It turns out that the value is in fact saved to EEPROM, and persists even if the UPS is power cycled!

And wouldn't you know - if set to 01, the UPS never switches to green mode!!

[GaryG_Accel]

Hey Teken,

I replied to you before but here's my final.

I installed new SMT3000RM2UC tonight.  Now we have 2 the same.

I removed the SMT3000R2X145 installed in 2013.

The new SMT3000RM2UC does have Green Mode - Enabled option. I was able to change it to Disabled in Configuration (Advanced) on the front panel.

I haven't checked the SMT3000RM2UC from February but I'm confident it's the same.

The much older SMT3000R2X145 did have Green Mode but the Configuration (Advanced) on the front panel did not display that option at all.

I am reporting this for anyone in the future and so this topic is formally Closed.

Thank you for helping.

[Teken]

Appreciate you sharing your experience and the (Green Mode) break fix on that one specific unit. 

In several other electrical forums some individuals have simply removed the green mode circuit from the system and used a jumper wire to bridge the missing components.

This was done in large part due to the failure of that PSU board mimicking the same behaviour you saw before.

Rock On . . . 🤟