Alfa P-3000/24 appears to charge batteries too quickly (from32% to 95%), Is my UPS faulty or batteries or neither?

[timematcher]

Hi guys.

Problem: The UPS seems to charge the batteries too quickly. 

Detail:
This is a 3KVA Alfa P-3000/24 UPS with two 12Volt DC batteries (a total of 24 volts). If batteries are discharged to 30-35% (on load voltage 20.x Volts, UPS reading 22.26Volts), it seems to charge the batteries in almost about 10 minutes (voltmeter:24.5 Volts, UPS reading: 27.xVolts)

Batteries are "Lead Acid water maintainable batteries" but the settings in the UPS are for AGM as default. I dont understand the difference and need advice. The only other options are Flooded or User.

Questions/Suspicion:

Obviously this cannot be right. Furthermore, even after having the batteries on AC charge via the UPS for more than 4 hours, each subsequent backup keeps on reducing until I need to charge the batteries using a separate battery charger or having them recharged by a battery guy. I want to understand what is wrong and whether its the settings that need to corrected or something else? I recently installed fresh batteries since I have was having problems with the previous ones.

Background:
I had problem with previous batteries when my UPS experienced a short circuit and needed to be repaired. After repair, It was found that cells of both of my batteries were shorted. So i installed new batteries and since then I am facing the problem as described above.

Screenshots:
I have attached the screenshots from WatchPower (the software that comes with CD)

Kindly help resolve the issue and help me make/implment the right software/hardware solution.

Awais

 

[Chris Hobson]

Morning Awais

I am not familiar with the Alpha P3000/24 and but it is clearly a Voltronic (or a Voltronic clone) product.

 

Three issues:

1. I don't like that your voltmeter readings and readings from the UPS software differ. Having been repaired once I think you internal voltage module on the UPS has been damaged and is giving inaccurate readings. 
2. The voltronic software is notoriously poor using voltage as a determination of state of charge. Ignore the SOC in the software and look at the LEDs on the unit (if it has any). The Axpert unit (which is related to your unit) has an LED that flashes whilst charging and goes on (lights up but stops flashing) when fully charged.Alternatively you can roughly see that the batteries entering float charge when the battery bank accepts 3% of the bank's Ah rating. So 3A on a 100Ah battery bank.  
3. The recuperation from 22.78V to 28.21V is too quick for my liking. What size are the batteries?

 

5 hours ago, timematcher said:

Batteries are "Lead Acid water maintainable batteries" but the settings in the UPS are for AGM as default. I don't understand the difference and need advice. The only other option is Flooded.

Set to flooded. "Lead Acid water maintainable batteries" are "flooded batteries". Better still is if you have the datasheet for your batteries you can set battery type to user (if this is an option) and then manually set to the required bulk and absorb voltages as determined from your batteries's datasheet.

I am concerned that you are discharging your batteries too far. One should not really ever go below 24V which is roughly 50% depth of discharge (DOD).

 

 

[timematcher]

@Chris Hobson Yes I agree. Its probably a Voltronic clone. See attached images of the UPS.

1. I don't discharge the batteries as I don't have any large load at the moment (2fans 60watt each and two tube lights 60watt max) . However, i think the UPS only float-charges the batteries and does not do a bulk charge long enough to provide them enough juice for the next load-shedding (which is one hour only). So after 3-4 load shedding(s) one hour each every 4 hours, decreases the juice of the batteries. If the batteries were being charged by the UPS (and no float-charged) this would not have been the case.
2. If I could set the battery to user, what should be correct settings for the batteries?
   
   Please see attached images and advise

Awais
 

[Guest]

The label above looked familiar ... like the one below, same factory maybe?

 

[___]

They might be using the same label printing service. It's hard to tell. But you might be on to something.

[Jaco De Jongh]

The product looks legit, they do have a model like this one. But the copy's looks legit too.

 http://www.voltronicpower.com/oCart2/index.php?route=product/product&path=24&product_id=174

Just for interest sake. 

Manual if someone needs to check anything.

http://www.voltronicpower.com/oCart2/files/manual/ALFA 3K&5K manual 20150708.pdf

[timematcher]

@Chris Hobson @plonkster @The Terrible Triplett

I have these settings options. Please help me configure the right options for my batteries. The batteries spec is also attached.

 

 

[___]

Set max charge current to 20 amps.

Can't see what the voltages should be. Tried googling for that spec sheet, only found the XP230, which appears to be flooded lead acid. So best I can do is go with generic voltages.

Set absorption voltage (aka bulk charging voltage) to 29V.

Set float voltage to 26.5V.

Battery cut-off at 21V is fine.

I would try to increase the back to grid voltage, though that depends on your load. With my load, a 50% DoD would correspond better with 24.2V (but I have AGM batteries). 23V seems a bit low. You may have to experiment.

Other forum members might disagree with the above voltages, but I think everyone will agree 28.2V is too low for absorption (aka bulk charging). More common voltages are between 28.8V and 29.6V.

[Chris Hobson]

Morning Awais

From looking at your settings.

Set back to discharge voltage to Full.

So it looks like your battery bank is a 150Ah bank and therefore you should not be charging at greater than 15A. Since Axpert only goes up in increments of 10A that means you are limited to 10A both max charging rate and max AC charging rate. (Please confirm that you have no solar panels installed and charging only happens via AC). At the moment you have it set to 50A which is way too high. You will damage your batteries.

Since you have light loads I would make back to grid at 24V. (Roughly a 50% depth of discharge (DOD). Anything more than this will seriously compromise your lead acid battery bank's longevity. 

What I suspect is happening is that the battery is discharging and then discharging again without every being fully charged as you back to discharge is set at float and not a higher value. These units manage to do some odd things and what you want is the unit to be in bypass mode with your batteries fully charged and to use battery power only when there is no AC power from the grid.

 

[Chris Hobson]

8 minutes ago, plonkster said:

Other forum members might disagree with the above voltages, but I think everyone will agree 28.2V is too low for absorption (aka bulk charging). More common voltages are between 28.8V and 29.6V.

The standard settings for lead acid and a Voltronic unit is 29.2 V for bulk and 27V for float. 

Just as a comment how did a Pakistani company decide on Phoenix as a product name. I certainly would not like my batteries to be "rising from the ashes".

[timematcher]

@Chris Hobson @plonkster Thanks for your useful input. I think that is what I was looking for. I also think that the unit stops charging the batteries too quickly and switches to floating charge in about 10 minutes which is an incorrect behavior.

I do not have any solar panels at the moment and I use only AC for charging.

I will try the suggested Bulks settings as soon as AC grid comes back on.

@Chris Hobson Phoenix is a catchy name, I think its all that is :). English although widely understood and used in our country, 90% truck drivers (who are the largest consumers of these batteries) are not literate enough to understand that! I think its easy on the tongue and seems a catchy name for most of those people. LOL  
 

[___]

12 minutes ago, Chris Hobson said:

Pakistani company decide on Phoenix as a product name

Victron has an inverter range called Phoenix :-) But that is because they use names from Greek Mythology. Hence Phoenix, Centaur, Lynx, Argo... The exception is their version of Linux on the CCGX which is Venus. That's from Roman mythology.

:-)

[timematcher]

@plonkster Thanks interesting finding

@Chris Hobson @plonkster

Its a 3-step charger so I understand the terms "Bulk Charging voltage" and "Floating charging voltage". 

Can you guys please explain to me a little bit the following terms to me?

1. Back to discharge voltage
2. Back to grid voltage
3. Battery cut-off voltage

Kind of confused about what these terms actually mean.

My new settings look like this now:

 

Do I also need to set battery type to Flooded or User?

Thanks for your helpful response.

Awais

 

[Chris Hobson]

9 minutes ago, timematcher said:

Can you guys please explain to me a little bit the following terms to me?

1. Back to discharge voltage
2. Back to grid voltage
3. Battery cut-off voltage

Kind of confused about what these terms actually mean.

I am going answer them in reverse order.

Battery cut-off voltage - At this voltage the UPS/inverter will shutdown to protect the batteries. The default setting (21V) is value is too low but changing it messes with the Axpert's software/SOC readings.

Back to grid voltage  - at this battery voltage the unit will force the load to be supplied by AC.

Back to discharge voltage - Once this voltage has been reached the unit will allow the load to be supplied by battery.

These two settings are used in conjunction with your output source priority. Since you are set with Utility priority (rightly so) they should not have any bearing until you have PV panels and that setting is either SBU or SOL. However I have seen stranger things and these may be active when they should in fact be inactive.

19 minutes ago, timematcher said:

Do I also need to set battery type to Flooded or User?

Thanks for your helpful response.

You need to set it to Flooded (which will then have 29.2V for bulk and 27V for float). If you set to User then you can choose the correct setting if you find that the Phoenix batteries require a slightly different bulk and float settings. Each setting you change you must click Apply on the button or it just reverts to the previous setting.

[___]

22 minutes ago, timematcher said:

Can you guys please explain to me a little bit the following terms to me?

1. Back to discharge voltage
2. Back to grid voltage
3. Battery cut-off voltage

Kind of confused about what these terms actually mean.

The inverter has several selectable programs and some of them allow you to implement a kind of self-consumption. This is specifically when you have solar panels. The inverter will then disconnect the grid (even though it is available) and run from the batteries and incoming PV during the day, while there is sun.

The "Back to" voltages control this. When the battery voltage hits the higher one, it disconnects the grid. When it hits the lower one, it reconnects the grid. If you have no PV, then these don't apply.

The last one, battery cut-off, is a safety feature. This is the voltage where the inverter will turn off to avoid damaging the battery. For a 12V battery this voltage is usually 10.5V, so 21V is a good voltage to use for that.

[Chris Hobson]

40 minutes ago, plonkster said:

Victron has an inverter range called Phoenix :-) But that is because they use names from Greek Mythology. Hence Phoenix, Centaur, Lynx, Argo... The exception is their version of Linux on the CCGX which is Venus. That's from Roman mythology.

So when I buy a Victron inverter to avoid any connotation with fire (and in TTT's case smoke) and ashes I will just have to go with their Greek god Multiplus (the Greek god of Mathematics) .

[Chris Hobson]

Hi Awais

Having looked at Phoenix's website it appear they only make automotive crank batteries. Ideally you should have deep cycle solar batteries. I am sure you can source some in your country.

[timematcher]

@Chris Hobson You are probably right. I should look for deep cycle batteries. They are available but much expensive.

[Chris Hobson]

53 minutes ago, timematcher said:

@Chris Hobson You are probably right. I should look for deep cycle batteries. They are available but much expensive.

You may find that since the solar batteries last longer that it justifies the expense. Have a look and see what the predicted lifespan of the Phoenix batteries are versus deep cycle batteries.