Sunsynk 8kW not allowing me to unselect Timer mode

[NickB]

Hi I am hoping someone can assist me here.

I am having a couple issues on the my sun synk 8kW inverter. My setup is completely off grid and running 10kW of LI batteries but they do not have compatible BMS.
I have been advised that for full off grid state the system should not the work mode timer engaged however it seems that even if I turn it off it re-enables itself after a minute or so.

I am having the following issues and I am not sure if its related to the work mode timer but the device is inconsistent about how it works.
1. Battery levels will indicate as low and then when they start charging they spike to 100% (I am installing thicker battery cables incase there is too large a current difference here however this can happen even in early morning hours when there is only 300-500w being put into the batteries, but then at other times will not happen even with 3.5kW of charge is being supplied to batteries. (After restarting the whole system the batteries will read a totally different percentage)

2. Even though there is sufficient solar power there is always a small draw of current from the batteries the moment the load draw goes above 700W or so. This will cause the batteries to go from charging at a good rate of 2kw when only 200W of load down to discharging the batteries at 200W with a load of 1kW. (note that if the load spikes the solar tracks with it even in the middle of the day. I can appreciate that batteries needing to balance the supply to account for any surges however I have had it run where it can supply 2kw of load and charge batteries at 3kW. There is unfortunately just no consistency to its operation.

I am running a solar assistant as I have used it with other projects like axperts and havnt ever seen anything like this but all appears to be firmware issues or settings causing the problem. If anyone can provide me with an idea configuration for off grid that they are running it would be greatly appreciated.

Below is an example of what is happening with the battery state of charge where it suddenly shoots up and in the morning when it was rebooted dropped down indicating a different level

 

Additionally here are my work mode timer setups, again it wont let me deselect the timer through the assistant or directly on the touch panel, it will unselect but after a minute revert.

 

thanks in advance for any assistance.

[mzezman]

Do you have Grid peak shaving selected? Ive noticed when this is selected it can cause issues with the Work Mode timer

[NickB]

I did have it on, I have disabled and that seems to have fixed the disabling of the work mode timer. Thank you very much

I am still having some of the historical issues however.

Where batteries are subsidizing the supply. This was charging properly an hour ago though, below or two screen shots for reference. Main issue is there is no consistency and even through there is more then enough solar power battery will sometimes always be discharged.

 

[mzezman]

When this happens (battery drawing when there is PV) what is the SOC of the batteries?

[NickB]

In this Particular case it is 51V of charge, The % is showing 96% at the moment but as you will see from the intro post the battery % is very unreliable.

Below I have also put the settings for the device however showing the float levels and where the device should charge too.

 

[NickB]

So as can be seen here the system is still not driving the charging of the batteries while there is a load.
From what I can tell I need to drop the load to about 200W or less and then it will start charging the batteries. But in the current setup it is constantly discharging that batteries. Note there is enough solar because if the consumption picks up to 3kw on the load the solar lags slightly but is able to supply it. 

This only sometimes happens however as the system has been seen to run correctly at times where it charges the batteries and supplies a fluctuating load.

[HiTech]

49 minutes ago, NickB said:

So as can be seen here the system is still not driving the charging of the batteries while there is a load.
From what I can tell I need to drop the load to about 200W or less and then it will start charging the batteries. But in the current setup it is constantly discharging that batteries. Note there is enough solar because if the consumption picks up to 3kw on the load the solar lags slightly but is able to supply it. 

This only sometimes happens however as the system has been seen to run correctly at times where it charges the batteries and supplies a fluctuating load.

Can you confirm you are seeing the same issue being displayed on the Inverters on-screen display.  IE, when Battery is not charging (with sufficient PV) as in this example, does the Inverter indicate the same reading.  I do trust the Solar Assistant, as it is theoretically reading directly from inverter, but worth checking as, you say this is inconsistent.  I've experienced a number of issues with PV providing load, especially when load is fluctuating, but never had an issue while charging batteries, only when batteries are full does the PV become erratic.
Seems you may be getting a false 100% charged from batteries and this is putting the inverter into the incorrect mode.  You mention incompatible BMS, thus trust you using AGM and based on battery model these settings (Battery) will need to be assessed.  
Seeing you have Solar Assistant, you may have the RS232 cable and can assess the batteries through PBMS Tool and check they are equalised.
(Lots of threads around Pbms on this forum).  
 

[system32]

23 hours ago, NickB said:

<SNIP>

Additionally here are my work mode timer setups, again it wont let me deselect the timer through the assistant or directly on the touch panel, it will unselect but after a minute revert.

Solar Assistant is a bit finicky with changing Inverter Settings.
It does work, but you need to be quick as SA keeps refreshing the values.
Best to use the Inverter Touchscreen to do most of your settings.

>My setup is completely off grid and running 10kW of LI batteries but they do not have compatible BMS.
Ensure that you have the latest SunSynk firmware.
Newer firmware supports more battery brands and battery models.
A few months back, there were over 35 brands and over 80 models on the list.
See Sunsynk_BatteryCompatibility_v9_English.pdf
https://www.sunsynk.org/documents/158739eb-0f51-48cc-8079-186fc7387385

You may also be able to use a RIOT to translate the BMS to SunSynk.

How is SA connected to the batteries?
It SA reading the battery BMS via RS485?

EDIT:
You may find the "InDesign-Installing-Generator-Sunsynk-HI-V2-new-bat-list.pdf" helpful
See https://www.sunsynk.org/documents

Edited September 8, 2022 by system32

[Kalahari Meerkat]

On 2022/09/07 at 11:50 AM, NickB said:

10kW of LI batteries but they do not have compatible BMS

how does the inverter decide how full/empty they are? with SA? and what are these batteries? 15S or 16S? presumably LiFePO4's?

[system32]

47 minutes ago, Kalahari Meerkat said:

how does the inverter decide how full/empty they are? with SA? and what are these batteries? 15S or 16S? presumably LiFePO4's?

The SunSynk inverter can use AGM/V (voltage) mode to estimate the SoC - it's not as good as using the BMS, but it works.
The problem with using Volts is that Lithium batteries have a very flat discharge curve.
SA can read the BMS SoC via RS485 or RS232, but SunSynk/SA/BMS can get SoC wrong after a power off of the batteries/inverter.
The systems normally need a full cycle to re-calibrate the SoC.
I suspect SunSynk in AGM/V mode uses both coulomb counting & Volts to calculate the SoC.

[RobN]

I'm not sure if this will make a difference; BUT if you have an "off-grid" system then "Prioritize Load" should be ticked in the work mode settings (next to Zero Export).

In an "off-grid" setup, you typically want to power your load in preference to charging batteries, and only use surplus PV power to charge batteries.

Your system is similar to mine, also running Solar Assistant and that's the way mine is set-up (but I have supported pylontech batteries).

My 2 pennies worth.

[NickB]

4 hours ago, system32 said:

Solar Assistant is a bit finicky with changing Inverter Settings.
It does work, but you need to be quick as SA keeps refreshing the values.
Best to use the Inverter Touchscreen to do most of your settings.

>My setup is completely off grid and running 10kW of LI batteries but they do not have compatible BMS.
Ensure that you have the latest SunSynk firmware.
Newer firmware supports more battery brands and battery models.
A few months back, there were over 35 brands and over 80 models on the list.
See Sunsynk_BatteryCompatibility_v9_English.pdf
https://www.sunsynk.org/documents/158739eb-0f51-48cc-8079-186fc7387385

You may also be able to use a RIOT to translate the BMS to SunSynk.

How is SA connected to the batteries?
It SA reading the battery BMS via RS485?

EDIT:
You may find the "InDesign-Installing-Generator-Sunsynk-HI-V2-new-bat-list.pdf" helpful
See https://www.sunsynk.org/documents

Thanks for the feedback.
Yes SA can be a bit finicky but seems to be correctly indicating the state of the sunsynk.

On this site currently installed there is no BMS running at all. The batteries are 2x Huawei ESM-48100A1  that I have never been able to get BMS running on. I am advised that sunsynk does not have compatible BMS for this and unfortunately neither does the Solar Assistant. I have been in direct contact with SA on this and although they have been helpful they don't have the supporting information to even begin the integration it would seem.

I believe at this point the primary issue is the fact that there is no BMS running as the voltages are reading quite erratically and the SoC is unreliable but un sure how to get around this any further unless there is advise to get it running with the ESM-48100A1 units. 

I have not been always running the internal sunsynk readings which would be based on voltage as I haven't been able to get the emulated BMS to work from the solar assistant as of yet.

regarding the actual solar assistant it is connected via RS485 to the sunsynk.
Can you confirm the latest sun synk firmware? currently showing COMM:e419 - MCU:3881 on the system.

 

[NickB]

12 minutes ago, RobN said:

I'm not sure if this will make a difference; BUT if you have an "off-grid" system then "Prioritize Load" should be ticked in the work mode settings (next to Zero Export).

In an "off-grid" setup, you typically want to power your load in preference to charging batteries, and only use surplus PV power to charge batteries.

Your system is similar to mine, also running Solar Assistant and that's the way mine is set-up (but I have supported pylontech batteries).

My 2 pennies worth.

Thanks for this.
I have tried both with this on and off and didn't seem to make much of a difference. I am glad to hear someone else running a similar setup that confirms it good operation. I have pylontechs on another location which are great but currently not in a position to replace these ones.

For confirmation if your batteries are fully charged do you find they are will discharge at all if there is sufficient solar available? 

[RobN]

They may discharge up to 50 W to supply the power needs of the inverter if the PV power capability is close to the Load requirement.  If there is more than enough PV power, then the batteries' SOC stays at 100% with no discharge.

[system32]

9 minutes ago, NickB said:

Thanks for the feedback.
Yes SA can be a bit finicky but seems to be correctly indicating the state of the sunsynk.

On this site currently installed there is no BMS running at all. The batteries are 2x Huawei ESM-48100A1  that I have never been able to get BMS running on. I am advised that sunsynk does not have compatible BMS for this and unfortunately neither does the Solar Assistant. I have been in direct contact with SA on this and although they have been helpful they don't have the supporting information to even begin the integration it would seem.

I believe at this point the primary issue is the fact that there is no BMS running as the voltages are reading quite erratically and the SoC is unreliable but un sure how to get around this any further unless there is advise to get it running with the ESM-48100A1 units. 

I have not been always running the internal sunsynk readings which would be based on voltage as I haven't been able to get the emulated BMS to work from the solar assistant as of yet.

regarding the actual solar assistant it is connected via RS485 to the sunsynk.
Can you confirm the latest sun synk firmware? currently showing COMM:e419 - MCU:3881 on the system.

 

For the latest SunSynk firmware, check this thread:

https://powerforum.co.za/topic/11687-sunsynk-5kw-8kw-and-12kw-latest-firmware-version/

Have you trued "Use Inverter Values" in SA?

[NickB]

5 minutes ago, system32 said:

For the latest SunSynk firmware, check this thread:

https://powerforum.co.za/topic/11687-sunsynk-5kw-8kw-and-12kw-latest-firmware-version/

Have you trued "Use Inverter Values" in SA?

I am currently running it on Use internal inverter values.

[NickB]

18 minutes ago, system32 said:

For the latest SunSynk firmware, check this thread:

https://powerforum.co.za/topic/11687-sunsynk-5kw-8kw-and-12kw-latest-firmware-version/

Have you trued "Use Inverter Values" in SA?

Thanks. I am going to request a firmware upgrade as I see mine is quite out of date. hoping they will still support through a solar man dongle.

[Kalahari Meerkat]

1 hour ago, NickB said:

 

The batteries are 2x Huawei ESM-48100A1

Ok, these seem to be 15S LiFePO4's they say in the spec sheet a charging voltage of 53.5V which is 3.5666666 etc V per cell, not too unreasonable, although I'd probably at least float it a bit lower, more like 3.45V per cell (@15S=51.75V), on the low battery end one can probably look at 3V per cell which would be 45V before calling the battery empty...

[NickB]

Just an update and hoping someone can assist on a recommendation form here.

I have successfully upgraded the firmware to the latest however I am still struggling with the system not charging correctly.
On a crystal clear day the solar seems to limit to about 1.2kw of generation split between batteries and load even though the SOC is only showing 70% on the batteries.
If I push up the load to 2.5kw the batteries will discharge about 500-700w and the solar will increase its generation to 2kw.

Any suggestions on a setting that could be causing this?

[Kalahari Meerkat]

56 minutes ago, NickB said:

Any suggestions on a setting that could be causing this?

Not really, but lets check some settings again...

you have charge voltages at:

float = 53.9V = (3.5933333 etc. V/cell) this is high for float... float should probably not be more than 3.45V/cell, I'd think...
absorption = 53,7V = (3.58V/cell, again a tad on the high end in my eyes)
equalization = 53.7V = (ditto...)

on the discharge end you have

STOP discharge Voltage = 52.4V = (3.49333333V/cell this is wayyyyyy off the mark....) this should be maybe 2.9 or 3V/cell, thus 43.5V or 45V, their output shutdown is set to 46.5V thus 3.1V/cell which is probably ok, to stop discharging, but at 3.49333V/cell your cells are mostly still full...

Numbers I was given for my 16S BSL were...
absorption = 54.6V which would translate to 51.1875V for your 15S battery (3.4125V/cell)
float = 54.5V which would translate to 51.09375V for your 15S battery (3.40625V/cell)

shutdown = 48V which would translate to 45V for your 15S battery (3V/cell)
alarm - 48.5V which would translate to 45.46875 for your 15S battery (3.03125V/cell)

the equalization is not needed, if you leave the battery long enough in float that the charge current drops to essentially 0, then the BMS should have balanced (equalized) the cells.

Your battery is made up of Lithium Iron Phosphate cells aka LiFePO4 cells, if you look at the attached table or go to the link from whence I borrowed it, you will see that your cells have a full charge voltage of 3.65V and a fully discharged voltage of 2.5V per cell, I would not recommend going this close to the edges, thus 3.45V on the top end is probably not too bad a value and 3 or 3.1V on the bottom end is probably also ok, so lets say 3.45V full and 3V empty...your setting have the battery empty/stop discharging at 3.49V, which in my book is propvol... WTF?

Edited September 15, 2022 by Kalahari Meerkat
grammar... and speeling...

[NickB]

Thanks. I have made the changes to meet this specification above but hasnt affected the systems base operation in that even when load is low the solar just tracks the load and draws small amount from the batteries. Below you can see solar is putting out 2.4kw along with the load as we spike the draw but in general with a 1kw load will just supply that only

[NickB]

Just to add onto this. Below you can see that the system will go up to 5kw of solar power being output, to meet this spec however it will only do it if the load drops to around 250W as seen below

[mzezman]

5 hours ago, NickB said:

Thanks. I have made the changes to meet this specification above but hasnt affected the systems base operation in that even when load is low the solar just tracks the load and draws small amount from the batteries. Below you can see solar is putting out 2.4kw along with the load as we spike the draw but in general with a 1kw load will just supply that only

Can you share your system settings screens? The work mode 1 and 2 screens as well as the battery screens

[NickB]

Sure. timer is off and work mode details provided.

[MdF]

I have been following this topic and trying to assess what is wrong with your system. You posted your Power Management settings above. Have a look at mine below for a 5Kw Deye and see if you can adjust accordingly?

MdF