On 2019/04/03 at 6:55 AM, jonesadr said:

Hi, Was wondering if anyone can assist. I have 2 x Axpect 5KVA inverters and 3 Pylontech 2.4 batteries, the system was running perfectly except I has running out of batteries during the night. I got another 3 X 2.4 batteries installed. The installer did not change any settings on the inverters. After the system running for a few hours there was a burning smell. The installer came back and checked the system and said every thing was correct. The next day my inverters "blew" up. 

Can anyone please let me know what setting should be change on the inverters for the 6 butteries.

Appreciate the assistance.

 

Ouch!

 

He should first replace your inverters and the follow the recommended settings

On 2019/03/01 at 1:45 AM, Coulomb said:

Since the charging LED is flashing, you're still in the bulk or absorb stage. So the relevant setting is the absorb (misnamed as bulk/CV) setting. I presume that it's at least 56 V. The float voltage setting only becomes relevant when charging is over (and the charging LED is on solid).

The inverter's reporting of state of charge (SOC) is very rough. Monitoring software will report the same SOC as the inverter, unless you have something like a BMV external battery monitor that counts coulombs, and the software is set up to read that. Even then, the external battery monitor relies on the battery getting full regularly, so that it can reset its SOC counter to 100%, and you don't seem to be getting there.

What voltage is the battery reaching during charging? Certainly, 54.21 V when charging is nowhere near 100% SOC.

What is the capacity (in amp-hours) of your battery?

What is the nominal power rating (in watts or kilo-watts) of your solar panels?

What is the voltage of your individual batteries making up your main battery? Often, it's 4 nominally 12 V modules in series; please measure each one. There is a chance that you have a shorted cell, in which case one or more modules will have a voltage about 2 V lower than the others. That would cause your symptoms of never stopping charging, since the battery voltage would never reach the absorb setting.

Finally, is there a chance that your inverter is a clone? Some clones seem to have problems with dropping out the Solar Charge Controller. Is the solar panel indicator on the LC Display always on when the sun is shining?

There is firmware to fix the premature float and the ragged soc measurement

 

 

Axpert Program 01
Conscious of battery life and would like to max solar energy use when available without depleting batteries.
Solar first & SBU, not ideal as battery used after solar energy too low until V reaches low level, triggering utility power.

What would be ideal is to monitor PV output vs load W and then switch based on:

PV A sufficient to service load, or battery discharge A is 0, or PV W > Output apparent power  = Solar first
PV A insufficient to service load, or battery discharge A is > 0, or PV W < Output apparent power = Utility first

Not sure if there is any freeware that can do this? 

Edited April 9, 20197 yr by Dean Lennox
updated text

You won't be able to utilize more than 3000W of PV power on that inverter alone. Are you planning on adding a seperate MPPT charge controller? Connect 4 string of 3 panels per string. This will give you 108V give or take. 4panels are too close to the 145V limit and chances are you will pop the inverter at some stage.

11 hours ago, Dean Lennox said:

What would be ideal is to monitor PV A vs load W and then switch based on:

Alas, measuring "available" (as opposed to "presently used") PV current or power is a tricky business. I think I heard of a Pi or similar connected to a sensor that was like a small solar panel, that gauged the "strength of the sun", from which you could estimate the available PV power.

Hi all,

I am new to this forum. Have registeted but are awaiting approval.

Meantime I have issues with solar system that worked well gor 12 months but then batteries deteriorated to point where batteries last less than 1 hour under 3kw ac load.

My confuguration is:

1x Mecer 5kw inverter

15 x 320 watt pv panels connected 3x5

8 x AGM G+ 12-200 Ahr batteries connected 2x4 in series to give 48V

Eskom is connected as bypass only, system is off grid.

Can I get recommendation on inverter settings? Also equalization since disabled currently.

Can I still rescue the batteries?

Johan Lombard

2 hours ago, Novice said:

Hi all,

I am new to this forum. Have registeted but are awaiting approval.

Meantime I have issues with solar system that worked well gor 12 months but then batteries deteriorated to point where batteries last less than 1 hour under 3kw ac load.

My confuguration is:

1x Mecer 5kw inverter

15 x 320 watt pv panels connected 3x5

8 x AGM G+ 12-200 Ahr batteries connected 2x4 in series to give 48V

Eskom is connected as bypass only, system is off grid.

Can I get recommendation on inverter settings? Also equalization since disabled currently.

Can I still rescue the batteries?

Johan Lombard

Welcome to the forum.

 

Do you have any monitoring installed? Lead Acid batteries which has gone bad are more often than not salvageable. There are some companies around who can revive a dead battery but you would have to try them out yourself as I've never used such a service. 

You can also get a Battery Desulphator Charger, which may, or may not revive those old batteries.  

... Maybe also share what your inverter and Charge Controller settings are, to what % to you discharge...

you say you off the grid, using 4S2P of 200A/H => 400A/H at 48V, giving you max useable 200A/H @ a 50% DoD, 

G

I have no monitoring installed.

Settings are Program no, setting:

01, SbU

02, 60

03, APL

04, SdS

05, AGn

06, Ltd

07, ttd

09, 50

11, 30A

12, 46

13, 54

26, Cu   56.4

Batteries are disconnected and being repaired so I could not note the settings that are not listed. But they are all on default values.

Comms pcb on my unit is damaged. Could not get a spare from Mecer. Any help on this??

Can someone tell me how to set the inverter up to operate on solar and utility even when no batteries are connected?

Hi All,

My issue seems to slot in with this thread title, so I'll just add it to this existing thread. I'm currently am struggling with 2 x 5kVa Axpert/Mercer inverters connected in parallel to 5 x 2000B pylontech batteries. The inverters keep wanting to overcharge the batteries (i.e. >54V) regardless of the bulk and float charge settings I use. Below are settings lower than the reccommended by Pylontech and the resulting battery voltage graph (I know the cut-off voltage is very low but this is to keep the SOC realistic). They seem to slow the charging phase down once the bulk voltage is reached but then steadily keep the voltage creeping up until the batteries go into protection mode and display the red ALRM led light. As soon as the PV input is cut all is well again. Seems like an inverter issue of some sort.

 

 

I am monitoring the system with ICC software although I'm waiting on the Pylontech cable as they are currently out of stock.

 

Any guidance would be appreciated.

 

GET THAT CABLE...

It's the all telling, all informing bit needed.

G

9 minutes ago, georgelza said:

GET THAT CABLE...

It's the all telling, all informing bit needed.

G

I know!! 😖

Just posting to make sure I'm not missing something obvious from my side.

Prob are... but without the cable you also won't know... as I understand the Inverter/Charge controller is flying blind atm... not having accurate data from the batteries re their true state.

G

4 hours ago, Novice said:

how to set the inverter up to operate on solar and utility even when no batteries are connected?

Sorry, it's not possible, unless it's a model with a 450 V SCC (MPPT).

6 hours ago, Novice said:

02, 60

This is one of the most important setting for saving your battery: maximum total charge current. Despite the fact that 60 A is the default, this is spot on for a 400 Ah lead-acid battery.

Does your inverter have setting 32, "bulk" charging time (actually Absorb charging time). With this, it's possible to work around the premature float bug to a degree. That bug may have contributed to your battery dying somewhat young.

3 hours ago, Super_mil said:

The inverters keep wanting to overcharge the batteries (i.e. >54V) regardless of the bulk and float charge settings I use.

Your settings seem OK except perhaps for Output Source Priority being Utility. That is fine if you are totally off-grid and AC-in is connected to a generator. Otherwise, you'll not get much use out of that largish battery and whatever PV you have during the day. If you really need the batteries to last as long as possible during a potential grid outage, that's reasonable.

I suspect that your battery isn't all that well balanced as yet, so some cells are racing up to a high voltage near the end of charge. I've never agreed with the manufacturer's advice of over 53 V for the absorb voltage. Even your figure of 52.5 V (3.50 VPC) is on the high side to me. I'd reduce it to 51.8 V (3.45 VPC) for a while, to see if that avoids the overshoots and if perhaps the overshoots reduce with time. You could go even lower, say to 51.0 V (3.40 VPC). Your float voltage could go as low as 50.4 V (3.36 VPC), though this will cost you a percent or so of run-time, while increasing life time.

How much PV power is connected to each inverter? What exact model are the inverters? Some older models (like my own) came with only a 60 A SCC (so some 3000 W max of PV charge current). I'm starting to think that it may not be a grand idea to overpower the SCCs too much. Those few models with a non-zero allowance for "excess" PV power in the specifications give of the order of 12.5%, e.g. 4500 W for a nominal 4000 W SCC. With too much PV power available, especially if the battery fills around noon, the SCC may overshoot too much and/or for too long, so this could be a large part of your problem. Preventing overshoots of PV power is definitely not a known feature of Axperts.

6 hours ago, Novice said:

Can someone tell me how to set the inverter up to operate on solar and utility even when no batteries are connected?

Your inverter cannot operate without batteries. 

14 hours ago, Coulomb said:

Your settings seem OK except perhaps for Output Source Priority being Utility. That is fine if you are totally off-grid and AC-in is connected to a generator. Otherwise, you'll not get much use out of that largish battery and whatever PV you have during the day. If you really need the batteries to last as long as possible during a potential grid outage, that's reasonable.

I suspect that your battery isn't all that well balanced as yet, so some cells are racing up to a high voltage near the end of charge. I've never agreed with the manufacturer's advice of over 53 V for the absorb voltage. Even your figure of 52.5 V (3.50 VPC) is on the high side to me. I'd reduce it to 51.8 V (3.45 VPC) for a while, to see if that avoids the overshoots and if perhaps the overshoots reduce with time. You could go even lower, say to 51.0 V (3.40 VPC). Your float voltage could go as low as 50.4 V (3.36 VPC), though this will cost you a percent or so of run-time, while increasing life time.

How much PV power is connected to each inverter? What exact model are the inverters? Some older models (like my own) came with only a 60 A SCC (so some 3000 W max of PV charge current). I'm starting to think that it may not be a grand idea to overpower the SCCs too much. Those few models with a non-zero allowance for "excess" PV power in the specifications give of the order of 12.5%, e.g. 4500 W for a nominal 4000 W SCC. With too much PV power available, especially if the battery fills around noon, the SCC may overshoot too much and/or for too long, so this could be a large part of your problem. Preventing overshoots of PV power is definitely not a known feature of Axperts.

Thanks so much for the detailed response @Coulomb, I really appreciate it. The output source is set to Utility as I'm completely off-grid with a generator back-up. I made that change after reading a response from @Chris Hobson to another user on the forum (to maximize the power put out by the generator, if I'm not mistaken). The inverters are both Axpert MKS-II 5kVa/5kW units (SOL-I-AX-5NB), which have the higher 450VDC PV input allowance. They are both running 71.50 firmware and each unit is hooked up to 6 x 355W panels (so, 2,130W per inverter, 4,260W total). 

I'm happy to lose some run-time in favour of battery life, so I'll give your lower settings a go today, as it looks like there are finally clear skies forecast.

Thanks again.

Hi all you veterans,

I now have full record of all the Mecer 5kw settings.

Is the reason for poor battery life hidden somewhere in this settings?

I have some uncertainty on settings 12 and 29, as well as 26 and 27. My settings can be seen in attached pictures. However got a reccomend from someone else for 47V for #29, 58V for #26 and 54.6 for #27.

Then do I need to think about the equalization settings, which is not active if #5 is set to AGM type batteries.

It would seem that I have solved my particular issue. I tried @Coulombs suggestion and lowered the voltages only for it to have no effect. I then figured I'd just check all the wires again and low and behold one of the red and black coms wires were loose. 😤 It was seated properly in the slot but the holding screw wasn't done up very tight so the cable pulled a bit when I added tension. Tightened it all up and all seems well. I can only assume the loose wire was causing some form of miscommunication between the two inverters. 

 

The offending wire.

Expected output readings finally happening with no voltage spikes

The afternoons results.

 

 

Oh my God! I'm going to tighten all these wires in my setup NOW. Thanks for the update!

14 hours ago, Novice said:

Is the reason for poor battery life hidden somewhere in this settings?

I can't see any glaring problems. Setting 28 should be SiG if you have a single inverter, but that should not affect battery life, as far as I know.

Greetings All

 

I would like to ask why the Axpert inverter manual says the incoming supply breaker for a 5kva should be 50 amps?

 

secondly could someone explain settings 23 (Overload when in battery mode)

13 hours ago, SeanM said:

I would like to ask why the Axpert inverter manual says the incoming supply breaker for a 5kva should be 50 amps?

Ignoring losses, the highest it needs to be about 5000 W for the load, plus 3000 W for the utility charger. Add 10% for losses, that's about 9000 W maximum (continuous). 9000 W / 220 V = 40.9 A. So theoretically, 40 A would be a little too low for the worst case, but usually utility charging is off or a lot less, say 1500 W. So generally, 40 A would be fine, with 6 mm² cable.

Quote

secondly could someone explain settings 23 (Overload when in battery mode)

In my manual, this is called "Overload bypass". "When enabled, the unit will transfer to line mode if overload occurs in battery mode". So when the battery is providing power to the load, and the load exceeds what the inverter can supply, enabling this setting will cause the unit to switch to the utility supplying the load. Otherwise, I believe the unit would pause (no output) with a warning code 07, overload. Setting 23 is disabled by default, but would normally be enabled.

[ Edit: Clone warning is about a different setting, restart after overload. ]

[ Edit: Would likely pause with warning, not stop with error. ]

Edited May 9, 20197 yr by Coulomb

Hi Coulomb

Thank you for this explanation.

 

May I confirm my understanding know:

 

Axpert 5000va/5000w inverter

AC input breaker 50 amps (10mm cable) to supply inverter loads and utility charging

AC output breaker 25 amp (2.5mm cable) as the inverter will handle 22 amps.