I have read the posts here so many times trying to pick up a resolution to my new inverter SOL-I-AX-5NB bought Monday 17 August 2020.

The unit will not use solar power to charge batteries no matter what combination of settings I use.  Watchpower software says software is 71.80.

If I have 01:SOL and 16:CSO the inverter will let battery run flat on load.  Watchpower only shows voltage as 130Volts~ but does not charge. When 12: 44volts is reached, Grid comes back and charges battery till 13: 55volts

If I have 01:UEI utility first and 16:CSO battery is slowly charged by solar.  The moment I turn off Grid power, solar goes off like its on the same switch.

I was about to conclude that solar is broken and turned off inverter with Grid off.  Solar happily charged battery to 100% this morning.  Now I am scratching my head.  I turn Grid on and solar stops charging immediately.  This is with 01:SOL or SBU.

If anyone has gone through this, please give a hint before I take this thing back.

01:SOL

02:60

03:APL

04:SdS

05:USE

06:lFd

07:Efd

08:230

09:50

11:30A

12:55 (to keep batteries topped up) 42 used during testing

13:56

16:CSO

18:bON

19:ESP

20:LOF

22:AOF

23:FEN

26:56.4

27:54

29:44

31:SbE

32:AUE

33:EdS

34:58.4

35:60

36:120

37:30d

39:AdS

18 minutes ago, Paul.Chari said:

Watchpower only shows voltage as 130Volts~ but does not charge.

Do you mean that the panel voltage is 130 VDC or thereabouts?

If so, in theory this is above the 120 VDC minimum MPPT voltage, but in practice, it seems that strange things happen at the low end of the PV voltage range.

Is it possible to reconfigure your panels, perhaps just temporarily with one string, to provide more panel voltage? You might find it suddenly starts behaving. 

The behaviour is certainly weird.

On 2019/02/04 at 7:48 PM, kobus joubert said:

Last night we pushed it again past 3.5 kw. It switched to bypass...FINE, but then it stayed on bypass with a base load of 216 Watt and SOC of 98%. No sun on panels as it was evening.

My guess is that setting 13 (back to battery voltage) is too high. To get back to using battery, you need the battery voltage to be over the value in setting 13. During the day, with solar charging, that happened right away. But at night, with no charging, it stayed below the value of setting 13, so it stayed in bypass mode.

I like to keep settings 12 and 13 pretty low, so that the system uses battery as much as possible, and therefore utility as little as possible. I use 51 and 52 V for settings 12 and 13 respectively, but I have a 16S LFP battery. The equivalents for a 15S Pylontech would be 48 and 49 V; with a smallish battery it might be better to use 50 V for setting 13.

3 hours ago, Coulomb said:

Do you mean that the panel voltage is 130 VDC or thereabouts?

If so, in theory this is above the 120 VDC minimum MPPT voltage, but in practice, it seems that strange things happen at the low end of the PV voltage range.

Is it possible to reconfigure your panels, perhaps just temporarily with one string, to provide more panel voltage? You might find it suddenly starts behaving. 

The behaviour is certainly weird.

Hello Coulomb

This is all the available panels right now.  Will try buy more next week to add and see.

I will hold on, on trying the 71.80a / 71.82 firmware until then.  As a backup/UPS, the thing is working which will have to do for now.

Thank you

 

Paul

PS: "Do you mean that the panel voltage is 130 VDC or thereabouts?" Yes I do.

Edited August 21, 20205 yr by Paul.Chari

The coulomb (symbolized C) is the standard unit of electric charge in the International System of Units (SI). It is a dimensionless quantity, sharing this aspect with the mole. A quantity of 1 C is equal to approximately 6.24 x 10¹⁸, or 6.24 quintillion.

 

Sounded so familiar lol.

57 minutes ago, Paul.Chari said:

It is a dimensionless quantity,

Actually, I beg to differ. Wikipedia says it's the SI unit for electrical charge. The number of elementary charges that one coulomb represents is of course dimensionless, like any number.

Quote

6.24 x 10¹⁸

Well, I do think a lot of myself ☺

5 hours ago, Coulomb said:

Well, I do think a lot of myself ☺

🤣

... and well corrected, 1 C = 1 Ampere over 1 Second, amount and duration.  Hardly dimensionless

On 2020/08/21 at 3:24 PM, Coulomb said:

Do you mean that the panel voltage is 130 VDC or thereabouts?

If so, in theory this is above the 120 VDC minimum MPPT voltage, but in practice, it seems that strange things happen at the low end of the PV voltage range.

Is it possible to reconfigure your panels, perhaps just temporarily with one string, to provide more panel voltage? You might find it suddenly starts behaving. 

The behaviour is certainly weird.

So just an update, took inverter back and they confirmed an error with the controller.  Have the repaired unit back and installed.  First test passed, battery stable and did not drain till flat.

In the morning will check solar, should have 200watts by 7am thanks to the new panels from the power store.  Just over 260 volts, 1amp at that time in the morning when I tested with multimeter.

On 2019/02/06 at 7:41 AM, Coulomb said:

Your bulk and float settings are way too high for PylonTech batteries. They should be 53.2 and 53.0 V respectively.

If you can reflash with the LFP version of 73.00e, the KettleKomp™ feature should prevent too-frequent switching to bypass (line) mode. Also, using the LFP version of the patched firmware should fix the problem of the far-too-sensitive low battery warning, so you should be able to change setting 29 back to a higher voltage, probably the PylonTech recommended one.

@Coulomb i also have a similar situation with a Must 5 kva pv 1800vhm invertor and UP5000 battery it remains in bypass but I think my settings are wrong for the battery im a complete noob and the installer also does not know why it stays in bypass either.The settings are as follows SBU and CSO.

Bulk 56.8

Floating 54.4

Low dc cut off: 48v

Field 20:Stop discharging when grid is available :48v

Field 21 : Battery stop charging when grid available :54v

According to the manual field 20 determinies how SBU will work.Any assistance with correct settings will be appreciated.I have 8 *360 watt panels this is a new install.

Edited July 31, 20224 yr by Kratos

8 hours ago, Kratos said:

i also have a similar situation with a Must 5 kva pv 1800vhm invertor

Ah. That's a different beast to the Axperts. I think must started off as Axpert clones, then gradually drifted towards their own design.

8 hours ago, Kratos said:

Low dc cut off: 48v

Field 20:Stop discharging when grid is available :48v

With an Axpert, when those settings have the same value, the effective "stop discharging when grid is available" setting is the low DC cutoff value plus 2.0 V (see the first part of FAQ #2). But with Must inverters, they may have changed this undocumented behaviour. Once in bypass, it will remain in bypass until it reaches the low DC cutoff value plus 4.0 V. If the Must acts the same as Axperts, this could explain why the inverter is staying in bypass. 4.0 V is a huge voltage change for an LFP battery; reasonable for lead acid. It would stay in bypass until 48+4 = 52.0 V, which is a higher voltage per cell than what I call full on my LFP battery.

@Coulomb i figured that it was not going out of bypass due to another setting related to lbu vs blu will tag you there since im not sure what ideal settings are.

16 hours ago, Kratos said:

due to another setting related to lbu vs blu

Ah. Those seem to be modes particular to the Must inverters. Must inverters aren't Axperts, although I think that early models started out as clones. I don't know what they are.

Yes also have no idea what they are but i need to set it so that I can use solar to power home and charge in day but have enough battery for the night.Please can you help with settings.this is what i have.

01 : output source: SBU this was on UEi

02:APL not sure if this is correct

05 :Solar supply priority: LBU - this is what was stopping it from moving off bypass since it was set to BLU and was trying to reach field 21 voltage which was impossible.So LBU looks at field 20 which I set to 48V based on forum feedback.

10: changed from SNU to oso to maximise solar panel usage.

11: default but not sure if its correct

14: Changed from LI to USE since it was ignoring fields 17,18,19 settings could be a bug but i dont know of this impacts charging profile for battery.

Need pylontech gurus to confirm if 17 to 21 settings are ok field 20 determines bypass mode or not. @Coulomb

17: Bulk :53.2

18:Float : 52.2v

19: low dc cutoff voltage :47.5 let me know if this is right for the battery also

20: Stop discharge when grid available:48v need to check if this is right.

21: Battery stop charge when grid available: 53v

Edited August 1, 20223 yr by Kratos