question

The battery needs to be connected to the left hand side and the load needs to be connected to the right hand side of the VE.CAN shunt. This cannot be swapped around. This is also not going to be a feature we will add at a later time.

If the negative load and the negative battery gets swapped nothing will break, only the current flow will be displayed in reverse. For example; when you load the system the shunt will indicate that the system gets charged.

But do watch out not to swap the positive and the negative (ie. reverse polarity)

Thank you Margreet,

I have now set the battery monitor to Quattro / VE Bus, which I expect should largely resolve the issue. For the time being the battery is still displayed at 46% / 54 VDC and the system is disabling the Fronius inverter (53 Hz). Also one of the MPPTs is not producing. Will this system re-calibrate at some stage and move away from the SOC that was based on the shunt? It has now logged negative Ah for a couple of days. I know how to set SOC to 100 % in the shunt but don't see any manual calibration setting anywhere else.

Thanks so much for your help.

My understanding from the research I've done is that based on the config we set, the battery SOC should have calibrated to 85% at the end of the bulk phase. However since there are two 70 A MPPTs which are comfortably exceeding the load, the inverter has stayed in "Inverting" kept the fronius OFF (at 53 Hz) and so the battery SOC has not changed. Is it necessary to force the inverter to "charging" for this SOC calibration to occur or can it happen while "inverting" Currently the MPPTs have already finished bulk and are onto absorption. System is 56.6 VDC (VRLA) with float defined at 54 VDC and max voltage 57.6 VDC.

I would suggest in this case to use the VE.can shunt rather than the VE.bus battery monitor.

The VE.can shunt will reset once charged conditions are met. current below a certain level and voltage above. for more info see the BMV manual (unfortunately we do not have a VE.can shunt manual).

Setup of the VE.Can shunt is via the CCGX.

If you want to keep using VE.bus battery monitor, set it up via VE.Configure and also read this link: https://community.victronenergy.com/questions/823/why-is-my-maximum-soc-stuck-at-85.html

Thanks Margreet,

For the time being the shunt cannot be used as the installers are no longer onsite to modify the wiring. I can likely ask the caretaker to pull out the RJ45 connecting to the shunt for the time being if you think this is a good idea.

I have been given the advice to put the system in DVCC mode since this would ideally have the Quattros read the voltage from the MPPTs but this has not solved the issue. Batteries currently read 52% @ 56.6 VDC so did not jump to 85% at or above 54 VDC as expected. Perhaps the unit needs to drop below 54 V and come up again with DVCC enabled?

In the meantime the MPPTs have entered state "ESS" despite there being no ESS assistant enabled (offgrid system) and I assume this is because of the DVCC enabling. 4.6 from this link below suggest with this arrangement the voltage parameters from VE config will be copied to the MPPTs meaning the absorption voltage would not be slightly higher as is requested in the link you sent.

Should we disable DVCC or should this result in the necessary calibration once we dip below 54 VDC tonight?

https://www.victronenergy.com/live/ess:design-installation-manual#mppt_solar_charger

The DVCC feature is to help with charge control, as your system has AC and DC solar charge sources. It will not help with this state of charge issue.

The ESS display is a visual bug and will be fixed in an upcoming firmware update - no harm though.

My opinion at this point is that if the VE.CAN shunt is physically wired incorrectly, its comms should be disconnected from the CCGX. Leaving the accurate and useful data from the MPPT and Quattro.

Then confirm that the CCGX is set to use the VEbus SOC. You may need to reset this to 100% by using the VEConfigure Remote feature and make a change to the SOC settings on the Multi in VEconfig (eg increase battery capacity by 1 Ah) so that SOC state data is reset to 100%.

The 85% jump you are hoping for may not come. That feature will limit the state of charge to 85% unless the battery is out of bulk and into absorption. I don't think it necessarily jumps to 85% just because you get to the absorption voltage.

Thanks Guy,

These are some interesting strategies, very useful to know we can force a SOC calibration (to 100%) by modifying the config. I will attempt this in the afternoon when the voltages suggest we have got there :) It's a pity about the visible bug, but knowing the system voltages it won't be an issue detecting what state things are in.

I had assumed the jump would happen on the back of the comment below. The part that had me stumped was that if the quattro was 'inverting' and not charging (all charging provided by solar DC) then would it detect the moment it moved through the bulk state. Certainly this morning it has not happened. My next strategy would have been to disable Solar DC charging in the hope the quattro would then progress from bulk to absorption using the AC coupled solar. It would be interesting to know if this would have worked.

"The Multi and Quattro have the advantage that it knows when the bulk state is finished, and can then sync the VE.Bus state of charge to 80%. Instead of (as the BMV does) having to wait until the battery is really full (sync parameters are met), and only then will it sync to 100%. "

https://www.victronenergy.com/live/vrm_portal:faq

Hi Guy,

I've done as you suggested, modified the Ah in the config slightly and this has put the system voltage at 85%. Progress! In any case we can now anticipate the issue that if the SOC is never shown to go above 85% the customer will think something is wrong.

I note the general online advice for this is to put the absorption voltage in the config a little bit below what the MPPT chargers are set to, but I suspect with DVCC enabled the MPPTs will copy this voltage and if so it will not solve the issue.

Any thoughts?