question

I've also just seen on one day, it charged the batteries, then there was less sun and high demand (charging my car) and so it discharged the batteries down to 20%, then the car was done, and it then recharged the main batteries again. This was the first time I have seen a double cycle in one day... Of course a few days later, I again say it only reach 40%, then quit for the day.

I also think its really bad practice to discharge slowly during the day back to the grid...I mean I am wearing out my batteries to supply back to the grid who pays me very little for the energy I give them, by the time night arrives, my batteries have lost 20 to 30% of what they had at full charge during the day because I gave it back to the grid...

The logic just seems horrible in nearly every way I look at it. Surely someone else has noticed how bad this seems...no?

There are different protocols used depending on your selection. You can set up your Quattros to keep the batteries charged to the max to ensure the use as a UPS, useful in areas where the grid is unreliable. Then there are other ways of setting up such as maximise battery life, minimise grid use, do not feed back into the grid, etc, etc. I think it is a matter of selecting the correct setting. You need to identify what you want and find the settings to work the way you want. I think there are (software) assistants that help you setup the way you need.

this might help

https://www.victronenergy.com/media/pg/Energy_Storage_System/en/configuration.html

you will also need to let the inverter chargers know that you have a Fronius. That way the inverter can communicate with the PV Inverters (Fronius) to throttle them back if batteries are fully charged and you are about to exceed your export limit.

You have not described your system sufficiently to know what is going on. Do you have a power metre that is connected to your system? Do you have a GX network hub, such as a Cerbo or a Raspberry Pi running a Venus OS?

Good luck, there are a few people here who will be able to assist. You should be getting assistance from the retailer of the Victron equipment you got. Victron does not usually deal with the retail customers so your retailer becomes the means to get assistance.

Hi @spinkb

I've looked into your system, and found:

when battery is fully charged, the system goes into 'float' mode, and the float charge voltage is set to 51.6V, this is the incorrect voltage for this type of battery, and makes the system not charge until battery voltage is down to float voltage.

I don't see a BMS communicating, is that correct?

Hello @spinkb

I hope @Daniël Boekel (Victron Energy Staff) comes back on to give you a few more pointers. It appears you have some work to do with respect to your battery settings. Look around on YouTube there is a number of Victron Energy videos one that explains how to set up for a lead acid battery and also Lithium batteries. I’ll see if I can find it for you. Here have a look at this

https://m.youtube.com/watch?v=mEN15Z_S4kE

you will need a Victron smart shunt or a cabled Victron shunt to determine SOC beyond just using a voltage based approximation. With the shunt you can Coulomb count and the system learns through the charge and discharge cycles as to the capacity and SOC of your battery.

I doubt that your BMS will be supported by Victron. I found this discussion on this forum and it points to a list of batteries (BMS) that are supported. Although your trio of BMS is unlikely to be supported, I suspect that you can still get the system to work. The above linked video will help. There is also another discussion going on with links to GitHub where a user/developer is coding to connect to BMS not currently supported by Victron. Here I found that for you also

https://community.victronenergy.com/questions/76159/victron-venusos-driver-for-serial-connected-bms-av.html

You will need to establish what sort of pack voltage will keep your cells safe while allowing your chosen BMS to take care of the individual cells. You will have to prevent the BMS triggering a disconnect. You’re likely to have to manually reset the system as many BMS disconnect themselves or require some sort of reset to recover from a over current/under voltage or over voltage condition.

Once again good luck.

Cheers

Gabriel

Hi @spinkb

I'll try again:

I've looked into your system, and found:

when battery is fully charged, the system goes into 'float' mode, and the float charge voltage is set to 51.6V, this is the incorrect voltage for this type of battery, and makes the system not charge until battery voltage is down to float voltage.

to add to that:

Please contact a good engineer to check your system, lithium batteries can be very dangerous in the wrong circumstances.

(sorry, I'm assuming here but I don't think you understood my comment about charge voltages)

What menu items allow configuring the battery chemistry and float values? I cannot find a menu that allows configuring this, and all my searches for manuals explaining where this is at doesn't reveal anything either...

Have you got control of your BMS? That photo you posted looks like a Daly BMS, could be another brand but will most likely be a smart BMS and you should be able to set some parameters via an App and Bluetooth. The first thing I would do is ensure the alarms on the BMS are set such that your battery cells are not going to be over charged or discharged. Although the BMS should be the last line of defence until you get a good understanding of what is going on you should safeguard your batteries.

As far as the Quattro is concerned try this

https://www.victronenergy.com/upload/documents/Manual-Connecting-other-lithium-battery-systems-to-Multis-and-Quattros-EN.pdf

Through some contacts I was able to get some Victron engineers to actually take control and look at my system. They fixed something in he config, but didn't tell me what. Something related to the "battery" type or capacity. Now its charging and working correctly.

Really wish I knew what config they changed...I went through all the menus many times, and I don't know what they changed that I couldn't change myself.

So the summary...I don't know what config was wrong, or what config was changed. Yes float voltage was wrong, but no one ever revealed where I can change that at, and so I don't know how the Victron people were able to do it either.