RCT 5KVA and Lithium battery settings

[Ockie Olivier]

Hi all, I am new on the forum and also very ignorant regarding the technical issues on my current inverter installation and settings and really need help. It is sad to advise that the people who did the installation and suppliers are unable to advise on the correct settings. I have manged to change some settings after reading the manual, but I have a feeling that there are settings which are not correct. My installation consists of the following:

1 x 5KVA RCT - AXVM3-5K48V inverter connected to 2 x US3000C Pylontech Batteries and 8 x Jinko/Tongwei 555W Mono Solar Panels and;

1 x 3KVA RCT - AXPERT 3K Inverter connected to 1 x UP2500 Pylontech Lithium Battery. Not connect to any Solar panels and only provides backup for lights. No issue with this.

My objectives are: 1) Optimize the Solar and Battery Capacity. 2) Reduce the usage of Utility power to save cost. 3) Ensure sufficient Battery capacity during Loadshedding (Power Outages).

I am running a small household for only two people with my Geyser charging from a separate Solar panel, but is also connected to utility power when needed (Geyserwise). Please note that my Stove  are not connected to the inverter.

It would seem that if I run on SBU mode and solar is not working in late afternoon, the batteries take over, but drops from 54V to 50V very quickly. Then soon after that the low battery alarm is sounded.

1	SBU
2	30A
3	APL
4
5	USE
6	LED
7	EFD
8
9	50
10	230V
11	20A
12	44V
13	51V
14
15
16	CSO
17
18	BOF
19	ESP
20	LON
21
22	AON
23	BYD
24
25	FEN
26	56.4V
27	54V
28
29	42
30	EDS
31	53.2
32
33	60
34	120
35	30D
36	ADS
37	NFE
93	NFE
94	10
95	47
96	3
97	21
98	4
99	24

 

[Mauritius B]

I would recommend changing parameter 5 to PYL and use BMS communication between batteries and inverter to ensure proper battery management.

With 2x US3000C you have a usable capacity of 6,6kwh when fully charged. Back-up time will depend on how much energy you draw from them during loadshedding

[Ockie Olivier]

Hi Maritius B, I have done that, but then got a code 4 (low Battery error), although the batteries showed full when the setting was on USE. I cleared the error 4 code by changing back setting 5 to USE and then batteries are full again. I have no idea why?

 

[Spys]

Double check the cable / pins between battery and inverter?

[Ockie Olivier]

Hi Spys! I wil check the cable.

 

 

[Ockie Olivier]

Hi Spys! I have actually now replaced the cable, but still getting the code 4 error.

 

 

[Chris Louw]

@Ockie Olivier  If you run the batteries on User setting 5 you must change setting no 26 to 52.5v and no 27 to 52.0 v. This is what most of us use .

Charging the battery at 56.4v will damage your batteries

[Spys]

Ok. It seems this is a popular topic with historical discussions. 

Follow the link to FAQ1 in the topic below

[Ockie Olivier]

I have read all of the above and still do not understand the error code 4. My conclusion from the above is that Pylontech batteries are not compatable with by inverter or the current firmware. 

 

[Scorp007]

1 hour ago, Ockie Olivier said:

I have read all of the above and still do not understand the error code 4. My conclusion from the above is that Pylontech batteries are not compatable with by inverter or the current firmware. 

 

The picture placed explains it. In short it comes down to the voltage level that will trigger the inverter to tell you the battery is getting close to cut off. See it as a warning like a low fuel light on a car fuel gauge. You might still travel 100km with the fuel left. 

Warning 04 is triggered a bit higher than setting 29. No matter what the comms might tell the inverter or if you don't use comms it still warns you. I have a light in the ceiling to alert me at this level. 

Edited April 25 by Scorp007

[Mauritius B]

On 2024/04/24 at 6:41 PM, Ockie Olivier said:

Hi Spys! I have actually now replaced the cable, but still getting the code 4 error.

 

 

You have 2 options:

1- Configure the system parameter 5 in User mode and set the proper voltages for a LiFePo battery as Chris Louw indicated or,

2- Configure the system paramenter 5 in PYL mode to allow communication between inverter and batteries. For this, you need the proper communication cable. If the cable is not correct, you will get error 61, not error 4. The cable pinout is customized so, a standard network cable is not working.

Read inverter and batteries manuals and re-check your system.

[Ockie Olivier]

Hi Mauritius B, Thank you. I am actually now running as per your point 1 and as per what Chris has said. As far as your point 2 is concerned, you are correct. I did initially have the error 61, but after rebooting batteries and inverter this disappeared and the error 4 came up. I then obtained a new cable from the supplier, and I still have the error 4. On the inverter it shows the error 4 and that the batteries are low. However, on the batteries itself it shows that they are 100% charged. It also shows on the inverter that the batteries are charging, but the error 4 remains and it shows now progress in terms of the batteries being charged. I have read all the manuals, but can't find any reference to this particular problem.

[Ockie Olivier]

Just to confirm. Here is my current settings. Are they correct? how can I optimize my system?

1	SUB
2	30A
3	APL
4
5	USE
6	LED
7	EFD
8
9	50
10	230V
11	20A
12	48V
13	48V
14
15
16	CSO
17
18	BOF
19	ESP
20	LON
21
22	AON
23	BYD
24
25	FEN
26	52.5
27	52.0
28
29	46
30	EDS
31	53.2
32
33	60
34	120
35	30D
36	ADS
37	NFE
93	NFE
94	10
95	38
96	3
97	26
98	4
99	24

 

 

[Scorp007]

59 minutes ago, Ockie Olivier said:

Just to confirm. Here is my current settings. Are they correct? how can I optimize my system?

1	SUB
2	30A
3	APL
4
5	USE
6	LED
7	EFD
8
9	50
10	230V
11	20A
12	48V
13	48V
14
15
16	CSO
17
18	BOF
19	ESP
20	LON
21
22	AON
23	BYD
24
25	FEN
26	52.5
27	52.0
28
29	46
30	EDS
31	53.2
32
33	60
34	120
35	30D
36	ADS
37	NFE
93	NFE
94	10
95	38
96	3
97	26
98	4
99	24

 

 

The inverter should have setting 13 higher than 12.

Back to utility and back to battery cannot be the same. 

@Spys gave a detail answer why. 

Edited April 26 by Scorp007

[Chris Louw]

@Ockie OlivierThe Best is to measure the battery with a multimeter when the error starts. With setting 29 set to 46v the error 4 will start when the battery reaches 48v . This is to check if the Inverter or battery is faulty.

Even if your battery is at 49v and should you boil a kettle and a fridge starts up the battery would be pulled down to 48v for a second and the error will start. The error will then stay until the battery gets to 50v before it will reset .

I run 3 x Pylontech 3000 for nearly 5 years and this does happen to me sometimes as well. There is 2 ways to get rid of this . Set 29 a bit lower 45.5v or get @ Coulomb kettle comp software . The software alows for more voltage drop before error 4 starts . I believe set at 46v the error will then start at 47v .

I will recommend that you adjust setting 13 to 51v and leave 12 at 48v .

Edited April 26 by Chris Louw

[Ockie Olivier]

Hi All, Thank you for your help and advice. I have done what you have suggested, and it seems that the system is now running much better. I have still not resolved the error 4 issue when I change setting 5 to Pyl. I am not getting the 61 error, which means that the system can see the batteries, but the error 4 remains. It seems that the system is not getting the correct data. Is it possible that it could be the firmware that is not up to date?

[Scorp007]

5 hours ago, Ockie Olivier said:

Hi All, Thank you for your help and advice. I have done what you have suggested, and it seems that the system is now running much better. I have still not resolved the error 4 issue when I change setting 5 to Pyl. I am not getting the 61 error, which means that the system can see the batteries, but the error 4 remains. It seems that the system is not getting the correct data. Is it possible that it could be the firmware that is not up to date?

As you are using 15 cell batteries their voltage would be a bit lower than the more common 16 cell lithiums. 

The 04 can be an error code or just a warning with ! mark in a tri angle. Can you confirm which of the 2 it is. Both refer to a low battery voltage. 

As you were initially overcharging the battery at a too high voltage it will also be a good thing to have an inspection done on the cells as your opening post also indicated that the voltage drops very quick to 50V when there is no solar. 

Have you looked when load you are drawing from them after sunset. 

Edited April 27 by Scorp007

[Chris Louw]

@Ockie OlivierThis is what my battery voltages is for the last 3 hours.This should give you a idea of what you can expect.You can see the voltage drop when the sun goes down. It is nearly 8pm and the batteries is 97% and 49.8v.

 

[Chris Louw]

Load for the same time

[razzor13bt]

this is a good guide and other manuals has good info on the website.

https://thesunpays.com/downloads/files/Inverter Settings LiFePO4.REV3.pdf

[Ockie Olivier]

@Scorp007 The 04 is indeed a warning with ! mark in a tri angle.

[Scorp007]

3 hours ago, Ockie Olivier said:

@Scorp007 The 04 is indeed a warning with ! mark in a tri angle.

It is thus a common warning if one either runs a high load or the battery is getting close to cut off. I get it on a regular basis when I run the micro and it goes away when micro is off. 

[Mauritius B]

I am using a very similar inverter (King 5kw) and Pyl batteries (5x US2000C) and I never get that warning except when reaching 20% SOC on the batteries, but mine are effectively communicating with the inverter.

I checked stored data from last February and voltage readout from battery at 21% SOC was 48.7V

Parameter setting: Return to grid 48V / return to batt 51V / low batt cut-off 45V

[Scorp007]

5 hours ago, Mauritius B said:

I am using a very similar inverter (King 5kw) and Pyl batteries (5x US2000C) and I never get that warning except when reaching 20% SOC on the batteries, but mine are effectively communicating with the inverter.

I checked stored data from last February and voltage readout from battery at 21% SOC was 48.7V

Parameter setting: Return to grid 48V / return to batt 51V / low batt cut-off 45V

There is a huge difference between having over 10kWh of battery power and running at 48V than a number of guys running 3kW inverters from 24V like me using perhaps only a 2.4kWh battery. 

Also after allowing for my 24V I cut out at higher level and also alarm with code 04 at a higher level. 

This in itself will cause the warning.

[Mauritius B]

On 2024/04/30 at 4:06 PM, Scorp007 said:

There is a huge difference between having over 10kWh of battery power and running at 48V than a number of guys running 3kW inverters from 24V like me using perhaps only a 2.4kWh battery. 

Also after allowing for my 24V I cut out at higher level and also alarm with code 04 at a higher level. 

This in itself will cause the warning.

Sure, but I still don’t understand why this is happening to Ockie with a 48v inverter and almost 7kwh battery capacity.

In fact, Ockie mentioned that his setup with the small 3kw and 1x UP2500 is working fine.