Matrix 5000 XR - w/Lead Calcium Telcom batteries - Must lower Charge Voltage

[Anonymous user]

We've had this 5000 XR for quite a few years, and it's been 100% reliable.

I just invested in 4 of a FIAMM Monolite Telcom style Lead-Calcium AMG batteries, 12v @ 145AH, and all seems well.

Almost.

(Note: I configured a battery rack for these batteries, using the internals/cables from the XR battery pack housing, along with its CPU module)

The maximum allowable float voltage on these batteries at 25°C is 2.26 vpc ±10mV

That gives a total pack float voltage of 54.24V ± 0.24V

With the factory normal 56.18V / pack float voltage, that's quite a bit over the acceptable range.

I realize that the Matrix products have reached "End of Life / End of Support" a couple years ago, so I'm not asking for any "factory support"... just help.

Is there a way (through software, I'll assume) to adjust this float voltage?

I'm an associate pastor at a church, I wanted a way to lengthen run-time, as well as move to a longer design life battery pack... these Fiamm's popped up, and I grabbed them... but the factory design spec says they will suffer from an increased risk of dry out, grid corrosion, and thermal runaway... which would be VERY bad on such large batteries.

This will require the help of a factory technician or engineer, who would have access to the production/repair calibration software... I'll assume (I was an electronics design engineer for 20 years before becoming the director of media ministries at this church where I work... so I'm totally familiar with this process).

Direct Message me if you can't reply here... and thanks very much in advance for any reply.

Ron

[BillP]

I am not sure how much circuitry APC used between lines of UPSs, but in the SU2200/3000 series a combination of R118 and R119 makes the voltage divider that sets the float voltage.  Who knows, lightening could strike and it may be the same in yours.  Good luck!

[Anonymous user]

Well, lightning struck, but not EXACTLY in the same place... but close! (R118 & R120, but not R119)

(and, BTW... amazingly, it was almost dead center of the picture I posted earlier)

I'll be sending the info to JJoseph.org for posting on his site...

APC SmartUPS Battery Float Voltage Calibration

[BillP]

Keep us posted on how go your efforts to reduce the float voltage on the batts in your UPS!

[Anonymous user]

Sorry... I wasn't clear... I got it solved... but I don't know if it's OK to post it all here....

[Anonymous user]

I'll go ahead and try this... see what happens...

I solved the puzzle of how to reduce the Battery Float Charge Voltage on this old unit.

Keep in mind that this IS an older model (firmware 5XM, unit s/n 820018xx), and therefore the PROG mode was not available, so the Float Voltage was not programmable.

PRECAUTIONS:   Take the upper "Electronics Unit" (EU) off of the lower "Isolation Unit" (IU).  Do NOT try any of this while the EU is connected to either the IU module or the battery pack. ALSO... the bank of capacitors in the Electronics Unit module hold quite the charge - discharge them at the battery pack connector, after disconnecting the battery pack, and after removing the Electronics Unit assembly from the Isolation Unit.  50V DC is enough to hurt if you get across it, let alone how much damage it can cause if you accicentally short something out to it.

BE CAREFUL!!

My initial check of the Float voltage on our Matrix 5000 was around 55.6 Volts total, Fiamm data (my TELCOM battery mfr) says this is too much, and will result in elevated temperatures, higher float charge current, and a higher possibility of out-gassing... so I had to make changes.

Long story short... I found the +Battery input to the board, traced it out, drew a partial schematic, and determined the best modification to allow adjustment of the Float Voltage.

[SCHEMATIC]

As you can see in the schematic, R118 (10.0K, 1%) is the "bulk" resistance, factory trimmed by R120 (1.33M, 1%). By slightly increasing the total value of R118/R120 parallel resistors, it would nudge the voltage getting to the TL062 op-amp upwards just a bit, making the CPU think that the "actual" Battery Voltage is higher, to which it responds by lowering the Float Voltage accordingly.

Note: I originally tried to modify the Output path that controls the charging, but that's the wrong place to go, as it's a PWM circuit, and I don't want to change HOW it charges... only the Voltage point at which it sets for Float.

(Photos can be "clicked" to enlarge)

(this photo shows the original R118 in series with the new POT/fixed resistors)

(this was all shown before I used some clear silicone RTV to hold it all in-place)

By moving R118 to the back side of the PCB (which is far more accessible after re-assembly), I could then add the new 1K fixed and 10K trimmer resistors in series with it. I used a fixed resistor across my POT for two reasons: (a) it "swamps" the effectiveness of the POT down significantly, making possible very fine adjustments (easily ±10mV)... and (b) I didn't have a 1k multi-turn POT at work. 😉

The "ideal" total series value (in series with the original R118) for my application would have been 232 Ohms, so I would have been better off with a 390-470 Ohm in parallel with the 10K trimmer, but again... a 1k fixed value is all I had at work, and I needed to finish it ASAP... and it works fine.

The calculations are based on a 5.00V reference.  With the original resistors, the R118/R120 parallel value comes out to 9925 Ohms. At 5.0V, that's 503.8µA.  With R179 at 100.0K and 503.8µA, that's a drop of 50.3 Volts.

Add the reference voltage of 5.0 to that, you get a calculated Float voltage of 55.3Volts (± resistor and Vref tolerances). With this formula, you can work backwards to your own desired Float voltage, to figure how much you need to increase the value of R118.

Hope it helps someone!

ps ron

[BillP]

That's pretty cool to figure that out w/o a schematic!  Thanks for the lesson in how the circuit works as well

[Anonymous user]

We've had this 5000 XR for quite a few years, and it's been 100% reliable.

I just invested in 4 of a FIAMM Monolite Telcom style Lead-Calcium AMG batteries, 12v @ 145AH, and all seems well.

Almost.

(Note: I configured a battery rack for these batteries, using the internals/cables from the XR battery pack housing, along with its CPU module)

The maximum allowable float voltage on these batteries at 25°C is 2.26 vpc ±10mV

That gives a total pack float voltage of 54.24V ± 0.24V

With the factory normal 56.18V / pack float voltage, that's quite a bit over the acceptable range.

I realize that the Matrix products have reached "End of Life / End of Support" a couple years ago, so I'm not asking for any "factory support"... just help.

Is there a way (through software, I'll assume) to adjust this float voltage?

I'm an associate pastor at a church, I wanted a way to lengthen run-time, as well as move to a longer design life battery pack... these Fiamm's popped up, and I grabbed them... but the factory design spec says they will suffer from an increased risk of dry out, grid corrosion, and thermal runaway... which would be VERY bad on such large batteries.

This will require the help of a factory technician or engineer, who would have access to the production/repair calibration software... I'll assume (I was an electronics design engineer for 20 years before becoming the director of media ministries at this church where I work... so I'm totally familiar with this process).

Direct Message me if you can't reply here... and thanks very much in advance for any reply.

Ron

[voidstar_apc]

You might try seeing if the Matrix responds to these instructions:

APC SmartUPS Battery Float Voltage Calibration

[BillP]

This is great info I will be doing this to the one i have soon! How did that work out for you have any updates to report is the ups still humming along? I also have 2 units for parts unless i can find a main board for them I have a 3000 and a 5000. The 3000 needs a main board and connectors between the IU and EU UPS distroyed this thing when they shipped it to me and it wasn't boxed to there crazy standards so i didn't any thing for them mangling it! The 5000 has mouse and moisture damage on the main board i think the mice did it in though! If any one has parts or needs parts message me we will see if they take my post down.

[Anonymous user]

Hello Ron.

I enjoyed very much your "hack"! You demonstrated that everything is possible... 🙂

I come to you with the hope you point me in the right direction: I have an old Matrix 3000 which served me for several years. I used it at home, because the power was, at the time, of poor quality.
Meanwhile, I haven't used it for some years.
The other day, I decided to use it again, with fresh batteries I bought, but it gives the error "Bypass rly fault call for service".
Can you please help in directing me to the problem and how to fix it?

Thank you very much for your help.

Best regards,

MacMatos.

[BillP]

Hi,

Bypass rly fault "A bypass relay fault will result in permanent bypass operation - load power will be lost during a utility failure." This may mean the bypass relay has failed or it could mean an issue with the DC BUS.

These unit are not considered user repairable however another member of the forum may be able to help you with the relay and BUS specification for testing purposes.  If you do attempt to service the unit do it at your own risk and use extreme caution.

[MarkC_apc]

Ron;

Interesting that you experienced such a battery failure (swelling, etc.).  I've seen this in the small UPS AGMs on occasion, but I'm surprised there is enough charge energy from even a 5000 VA unit to cause such a failure in a large battery bank.  It concerns me because I'm planning on using some Northstar "Blues" in my 48 volt emergency backup (off-grid) with a more modern SMT2200 UPS.  I have not considered that the charge circuit of a UPS would adversely affect a 150-200 Ahr, 48 volt bank - used to "float" the pack only.  I won't likely have such a problem anyway as the off-grid system is mainly weekend and the "float" charging will only be for a day - then rest for a week or two.  I believe the SMTs are programmable anyway.  Just curious as to what your theory is about the battery failure - like to NOT have that happen!

Nice work on the mods to the circuitry!  

Mark

[Anonymous user · Accepted solution]

Thank you for your reply.
For now, I'm cleaning the inside of the EU Module and I saw that the PCB pins which go to the IU are somewhat oxidised. I will clean them and, if needed, I will tin them.

After that, I will reassemble de EU and test the UPS again... 🙂

Let's hope...

[Anonymous user]

Hi Ron

How many amperes the matrix 5000 charge to battery after fully discharge?

How long to full charge your battery?

thanks you for your issue and infomation!

[BillP · Accepted solution]

Ron, if you're still out there somewhere, I would like to speak to you ASAP about an issue we're having where we lost two units and something is wrong on the very same board you show here.  I'm desperate to find someone knowledgable about these units right now.

Message me or reply here if you are out there.