On 2021/02/09 at 10:06 AM, BasZ said:

I had more luck with setting [5] on LBU instead of BLU (I did not change anything else). The battery supplies the load when it can and bypass is only coming on sporadically.

Can you please post a link to the manual for your Axpert model here? You have a different model than me and the setting numbers do not align (and mine does not have any setting with the values BLU/LBU)

On 2021/02/09 at 10:06 AM, BasZ said:

- I had thought that with all my settings above and [5] on LBU that Eskom would keep my battery at 50V, but am seeing that it is drawn down all the way to 48V during the night. Why would this be? I am assuming this to be harmful for the battery?

Not fully understanding yet what setting 5 is or does - keep in mind that your inverters will draw self-consumption from the batteries even while running in utility mode. Depending on your model this can be anywhere between 40W - 70W per inverter. Not sure if you have taken that into account so far

49 minutes ago, wolfandy said:

Can you please post a link to the manual for your Axpert model here? You have a different model than me and the setting numbers do not align (and mine does not have any setting with the values BLU/LBU)

Not fully understanding yet what setting 5 is or does - keep in mind that your inverters will draw self-consumption from the batteries even while running in utility mode. Depending on your model this can be anywhere between 40W - 70W per inverter. Not sure if you have taken that into account so far

Can't find it online, so posting scans of the relevant pages. Never mind the scribblings

Synapse 4.0+ settings.pdf

Thanks @BasZ - this definitely helps. And I believe you are on the right track

Let me try to explain setting 5 to my best knowledge:

• BLU: Your PV will first be used to charge your batteries. As long as your batteries are below setting 21 (52.0V in your case), all available PV will used to charge the batteries. The loads will be powered by utility. Once your battery voltage is higher than setting 21, PV will also be used to power the loads.
  This setting focuses on charging your batteries to 52.0V as quickly as possible at the expense of using more utility to power the loads in the meantime.
• LBU: Your PV will first be used to power your loads. As long as your batteries are above setting 20 (50.0V in your case), available PV will be used to power the loads. If PV is not sufficient to power the loads, it will draw the difference from the batteries (until they are drained to setting 20). If PV exceeds the loads, the excess energy will be used to charge the batteries.
  If your batteries are lower than setting 20, the loads will run on utility and any available PV will be used to charge the batteries until setting 20 is reached.
  This setting focuses on reducing utility usage. However, what can happen is that if your loads are too high and/or you have too little PV for the amount of battery storage, your batteries might never get even close to fully charged

I am running basically like your LBU setting. My system powers my loads and excess energy is used to charge the batteries. I have sufficient panels on the roof that (for most time of the year) my batteries will get fully charged throughout my solar day. On some days this is later in the day (which means that I pretty much max out my PV production potential), on other days it is earlier 

On 2021/02/09 at 10:06 AM, BasZ said:

- I had thought that with all my settings above and [5] on LBU that Eskom would keep my battery at 50V, but am seeing that it is drawn down all the way to 48V during the night. Why would this be? I am assuming this to be harmful for the battery?

No, the inverter will not actively start charging your batteries (as your setting 10 is OSO). It will simply stop drawing from the batteries to power the loads when the batteries reach 50V and switch over to utility.

As per my earlier post, however, the inverters will draw self-consumption from the batteries even while running in utility mode. Depending on your model, this can be anywhere between 40W - 70W per inverter. For example, in my case it is 2x 45W = 90W. So if my system switches over to utility at 02h00 in the morning and my panels only start producing around 07h00, then the inverters are using 90W x 5h = 0.45kWh from the batteries during that time. You need to determine for your system what your inverters actual draw is when running on utility and for how long your system usually runs on utility every night (though probably use something close to worse-case scenario). Then you need to see if your current setting 20 is appropriate or if it needs to be adjusted. If you batteries last time were close to 48.0V, then you probably need to increase setting 20. If they were still around 48.5V, then you might even be able to lower setting 20 a bit (depending how adventurous you are and how much you want to maximize your utility savings). This is basically different for every system, so you need to play around with your system a bit and figure out which values works best for you. Just keep in mind that if your battery does hit the 48.0V (setting 19), your system will switch off and you will be in the dark...

2 hours ago, wolfandy said:

Thanks @BasZ - this definitely helps. And I believe you are on the right track

Let me try to explain setting 5 to my best knowledge:

• BLU: Your PV will first be used to charge your batteries. As long as your batteries are below setting 21 (52.0V in your case), all available PV will used to charge the batteries. The loads will be powered by utility. Once your battery voltage is higher than setting 21, PV will also be used to power the loads.
  This setting focuses on charging your batteries to 52.0V as quickly as possible at the expense of using more utility to power the loads in the meantime.
• LBU: Your PV will first be used to power your loads. As long as your batteries are above setting 20 (50.0V in your case), available PV will be used to power the loads. If PV is not sufficient to power the loads, it will draw the difference from the batteries (until they are drained to setting 20). If PV exceeds the loads, the excess energy will be used to charge the batteries.
  If your batteries are lower than setting 20, the loads will run on utility and any available PV will be used to charge the batteries until setting 20 is reached.
  This setting focuses on reducing utility usage. However, what can happen is that if your loads are too high and/or you have too little PV for the amount of battery storage, your batteries might never get even close to fully charged

I am running basically like your LBU setting. My system powers my loads and excess energy is used to charge the batteries. I have sufficient panels on the roof that (for most time of the year) my batteries will get fully charged throughout my solar day. On some days this is later in the day (which means that I pretty much max out my PV production potential), on other days it is earlier 

No, the inverter will not actively start charging your batteries (as your setting 10 is OSO). It will simply stop drawing from the batteries to power the loads when the batteries reach 50V and switch over to utility.

As per my earlier post, however, the inverters will draw self-consumption from the batteries even while running in utility mode. Depending on your model, this can be anywhere between 40W - 70W per inverter. For example, in my case it is 2x 45W = 90W. So if my system switches over to utility at 02h00 in the morning and my panels only start producing around 07h00, then the inverters are using 90W x 5h = 0.45kWh from the batteries during that time. You need to determine for your system what your inverters actual draw is when running on utility and for how long your system usually runs on utility every night (though probably use something close to worse-case scenario). Then you need to see if your current setting 20 is appropriate or if it needs to be adjusted. If you batteries last time were close to 48.0V, then you probably need to increase setting 20. If they were still around 48.5V, then you might even be able to lower setting 20 a bit (depending how adventurous you are and how much you want to maximize your utility savings). This is basically different for every system, so you need to play around with your system a bit and figure out which values works best for you. Just keep in mind that if your battery does hit the 48.0V (setting 19), your system will switch off and you will be in the dark...

Wow, thanks for taking the time to pen all that down! Makes sense, you are right about the inverters drawing from the batteries (although wouldn’t they draw from Eskom at a certain point?)

ok, so it looks like LBU is the way to go for me. My panels are in the sun pretty much all day so 4kWp is enough to charge the 8kWh battery pack quite quickly. 

Besides the Victron MPPT I can now also see a lot more on the CCGX and it is starting to make more sense (even without being able to extract any info from the Axperts). 
 

Last bit that I am still struggling to understand is why the Inverter goes into bypass mode (solar/battery as well as Eskom are supplying to the load) sporadically when my loads are low, when there is enough solar capacity and the batteries are at more than 52V. Any clue?

Promise not to ask any more questions!

2 hours ago, BasZ said:

(although wouldn’t they draw from Eskom at a certain point?)

No, to my knowledge the Axperts are not designed like that

3 hours ago, BasZ said:

Last bit that I am still struggling to understand is why the Inverter goes into bypass mode (solar/battery as well as Eskom are supplying to the load) sporadically when my loads are low, when there is enough solar capacity and the batteries are at more than 52V. Any clue?

This is a bit difficult to tell without having any data to look at from the inverter. Usually I would guess that it happens if you switch on a large load (e.g., kettle), which could cause the battery voltage to momentarily drop below your 50.0V - but you are writing that this also happens if you only have little loads.

Have you thought about investing into ICC? For me this was a great investment, as it really gave me full insight into my system

Another question out of curiousity: You are writing that you have a CCGX. Other than the MPPT, is there anything else connected to it?

5 hours ago, wolfandy said:

Another question out of curiousity: You are writing that you have a CCGX. Other than the MPPT, is there anything else connected to it?

The CCGX connects to the MPPT, the Blue Nova battery and a ET340 three phase meter, that I use to Measure Eskom input and inverter output. The CCGX is a bit confused because it counts Eskom in twice (because Eskom is also part of inverter out, but it adds them up). 

This is a temporary situation. When I have enough funds or when my Axpert dies on me I will invest in a Victron Multi. Not understanding what the Axpert does and not being able to connect it to the CCGX is frustrating. 

thanks again for all your replies. While not perfect it is working and that’s what counts! Will take a look at ICC

3 hours ago, BasZ said:

The CCGX connects to the MPPT, the Blue Nova battery and a ET340 three phase meter

Ok - thanks

I don't think that ICC supports Blue Nova yet, so you unfortunately won't be able to get the BMS data to control your inverter

But you could connect the MPPT to it and then at least have full view of your production/consumption (apart from those things still directly connected to Eskom)

@wolfandy The CCGX already gets all that info from the MPPT and puts it on the the VRM portal, so if ICC can't connect to Blue Nova then I think it wouldn't add anything?

1 hour ago, BasZ said:

The CCGX already gets all that info from the MPPT and puts it on the the VRM portal, so if ICC can't connect to Blue Nova then I think it wouldn't add anything?

If ICC could communicate directly with your Blue Nova (like it does with my Pylons), then you could use ICC to switch between Solar/Battery and Utility based on the accurate SOC from the battery BMS instead of the Axpert's voltage readings. You could throw a Victron BMV into the mix to get ICC to determine an accurate SOC for your Blue Novas and switch your Axperts based on that.

You would then also have a complete view of everything that is going on in your system and could see in detail when your Axperts are switching to grid (and determine why). Here is my system as example (PV from my Victron MPPT):

I updated and restarted my Pi this morning, so I unfortunately do not have any better charts to show at the moment.

Drop me a PM if you want to have a quick chat in person about this

On 2020/01/07 at 11:46 AM, wolfandy said:

Maybe my understanding is wrong and I am over-complicating things: Do the MPPT and the Pylon BMS need any kind of direct communication? Or does the MPPT change between bulk, float, etc purely based on the voltage that it reads? In all the Victron schematics that I found both the Pylons and the MPPT are always connected to a Venus device. 

Hi everybody! Greetings from Croatia...

This is my first post on this forum. I've been reading you for a long time, and most of my solar issues over the years are being resolved by reading your experiences and advices. Thank you all for that & for your persistent enthusiasm.

I'm completely off grid for 12 years now. Currently, I've three pip5048MK ( firm. 71.90,  2.40), (2 paralleled, one currently not connected). I've 5kWp solar panels on the roof, and additional 6 kWp in garage waiting to be installed. Besides this, I've recently replaced my AGM battery bank, with 6 pylontech US3000C batteries. 

For me everything works fine, I've crimped the cable as per instructions I read here on the forum. I've communication going between my 5048MK and pylontech batteries, but I'm worried with high voltage settings for program 26=53.2 V, and program 27=53.2V with program 5 = PYL. So I've changed the this to USE on both of my inverters, and set program 26=52.5V, program 27=51.8V, as Coulomb suggested in one of the threads. I personally think that the most troublesome setting in PYL  profile is program 27=53.2 V, to keep such a high voltage throughout the day is insane, and will definitely prove to be detrimental to batteries over the time. I do not have ICC or any other monitoring devices such as Victron BMV 7xx. 

Anyhow, I wanted to repeat question from wolfandy;"  Do the MPPT and the Pylon BMS need any kind of direct communication? Or does the MPPT change between bulk, float, etc purely based on the voltage that it reads?"

Why?

Because if it is purely voltage based decision, than since I'm off grid I really do not care about wrongly displayed SOC on my Voltronic devices, and overnight I never really discharge more than 20% of my batteries,  and hopefully(?) they will over time update their firmware and change (or to enable user to change) value for program 26, and 27.

But there is another solution to this. If there are some other benefits, that I do not see now, to have Voltronic BMS to Pylontech BMS direct communication, I can install third 5048MK unit, not have it connected with PV,  set program 5=PYL and establish BMS to BMS communication. On two other units, that have PV connection, I would set program 5=USE, with  program 26=52.5V, program 27=51.8V. In this layout, I have a BMS to BMS communication, inverters are in parallel, and they exchange information about SOC and other stuff that inverter with PYL setting is getting from Pylontech BMS, and I do not risk overcharging the batteries, since inverter with PYL setting do not have any PV connected to it. Only drawback of this solution is self consumption of the unit that is not connected to PV (and initial investment , but I already have it, and there is investment anyhow for monitoring device, on a plus side you have a spare inverter, and less strain on each inverter). To minimize self consumption , during winter nights, I can just turn it off (or even turn off two of the 5048MK units), and leave single inverter running. In the morning, as soon as light is bright enough,  inverter with PV connected will work as charger automatically, and I would have to turn on manually the inverter without PV(but with BMS to BMS communication).

I've put this idea to test, and it works as described above.

What do you think? Is it crazy, or does it make sense?

1 hour ago, mrd said:

Do the MPPT and the Pylon BMS need any kind of direct communication? Or does the MPPT change between bulk, float, etc purely based on the voltage that it reads?"

Welcome mrd 🙂

After running with my setup now for about 12 months, my experience is that the comms between MPPT and BMS is not required. My system is happily chugging along without it. On a daily basis the MPPT does it's job based on the voltage settings I manually entered (52.5V Bulk/Absorption and 51.8V Float) - and my Pylon BMS reports 100% SOC through ICC when the MPPT stops charging and reduces production down to my current loads

On 2021/02/11 at 12:32 PM, wolfandy said:

If ICC could communicate directly with your Blue Nova (like it does with my Pylons), then you could use ICC to switch between Solar/Battery and Utility based on the accurate SOC from the battery BMS instead of the Axpert's voltage readings. You could throw a Victron BMV into the mix to get ICC to determine an accurate SOC for your Blue Novas and switch your Axperts based on that.

You would then also have a complete view of everything that is going on in your system and could see in detail when your Axperts are switching to grid (and determine why). Here is my system as example (PV from my Victron MPPT):

I updated and restarted my Pi this morning, so I unfortunately do not have any better charts to show at the moment.

Drop me a PM if you want to have a quick chat in person about this

So, just to let you know that with the new settings I am in a much better space with my system. I managed to tweak some of my consumption by installing a timer on my wellpoint pump (it was engaging early morning when I irrigate the garden) and pushing its consumption to late afternoon. Since then my Eskom consumption has reduced significantly and my battery doesnt drop below 50% anymore. Jay! I think I will continue in this way until I need to replace my inverters and at that point install a Victron product that will allow the CCGX to understand and manage completely what is happening. Many thanks again for your help and patience @wolfandy!

Hey..

 

I like and want to look into this. 

Can you maybe share some photos of you setup?

Thank you

8 hours ago, Barryv said:

Can you maybe share some photos of you setup?

Sorry - have recently changed my setup and am no longer running Axperts

But what info are you looking for exactly?

9 hours ago, Barryv said:

Hey..

 

I like and want to look into this. 

Can you maybe share some photos of you setup?

Thank you

If your question was directed at me: I am travelling, only back end of july, so can only send then. Pls send a reminder if you would like to see my setup, OK?

My setup:

MPPT: Victron

Inverters: 2 Axperts in parallel

Battery: Blue Nova

controller: Victron CCGX

Hi, i use to run a victron mppt with my axpert inverter.

Setup looked like this. Et112 at DB, that Connect to the Venus OS on raspberry Pi.

Victron mppt also connect to Venus OS.

Set Axpert to SBU. And set the voltage on the axpert as needed. 

The Axpert will then swith between eskom and batteries based on the Voltage settings.

Remember to set the battery voltages also on the MPPT.

Just rember that the Axpert is not that accurate when it comes to Voltage. (At least it was in my case like that) 

Hi all,

I am also thinking of installing a 150/85 Smartsolar controller on my Axpert setup. I have the Solar Assistant device installed. Will I still be able to see the Victron data on my screen. How will the Victron interface with the Solar Assitant device?

Thanks in advance