SBMS0 with "Two-signal BMS Support" only permitting solar charging, not generator through Victron Quattro

[Dustin Dudley]

I have an off grid system with a Quattro 24/5000/120-2x100 120V, connected to a Cerbo GX. The system uses 19 220W solar panels to charge 32 EVE Lifepo4 280Ah prismatic cells (28.6KWatt hours of storage).  That entire system relies upon Victron equipment (5000 W Quattro Inverter, Victron Cerbo GX, Victron Smart Shunt & touch display, and 2 150/70 Victron Solar Charge Controllers).

The system is also connected to a generator (11Kw) for times when there is insufficient solar to power everything and keep the batteries charged sufficiently to make it through the night.

The system utilizes an Electrodacus BMS (SBMS0), which toggles the Victron Quattro’s charger on and off as appropriate and also toggles the two Victron MPPT 150/70 – tr VE.Can SmartSolar charge controllers on and off as appropriate. This is accomplished utilizing an “Assistant” in the VE Configure file called “Two-signal BMS support.”

Although the system functioned flawlessly for over a year, a few months ago the Victron Quattro stopped charging the batteries with power provided by the generator. The batteries are still charging when there is sufficient solar and the BMS is still toggling the MPPT solar charge controllers on and off as appropriate. However, the system will only utilize the power being provided by the generator to carry the existing power demand/loads and will not charge the batteries. I am stuck using the generator aa lot so that it carries the loads and allows the MPPT solar charge controllers to recharge the batteries.

When I go to my Victron Dashboard online (Or when I look at the Victron touch display) they both indicate the system is in “Passthrough.” I have tried many changes to the configuration of the Quattro and have had no luck whatsoever. I have followed the suggestions in the list that comes up when you click on the “Passthrough” icon on the Victron Dashboard online, with no success. I have tried a different generator. I have tested the SBMS0 state transitions and it appears to be functioning correctly (as also indicated by the fact that it is turning the MPPT solar charge controllers on and off as it should based upon battery charge levels).

Any suggestions would be greatly appreciated.

[Dacian Todea (electrodacus)]

Are you using a different EXT IOx to control the Victron MPPT 150/70 maybe EXT IO4 and some other EXT IOx maybe EXT IO5 to control the Quattro charging ?

Make sure that the EXT IOx (maybe IO5 or IO6) controlling the Quattro charging is set as type 1.

Not sure how exactly the passthrough mode works on Quattro and what options are there for it.

Since passthrough likely has a limit set for input current and the battery/inverter need to be there to cover the difference in case load is higher than the input passthrough limit then there will be no charging.

Maybe you need to switch the ON/OFF of the inverter to charger only to allow charging from generator but not sure.

I do not have a Victron inverter/charger and also I do not have grid or a generator so I did not looked in to this configurations. Maybe someone that has this setup can help.

[sailingharry]

On my Multiplus when I set the 2-signal assistant, it dedicates two contacts to "allow to charge" and "allow to discharge."  These will be run through the SMBS0.  Assuming the Quattro is similar,  you could try to remove the signal wires to the Quattro, and insert simple jumpers.  This would give the Quattro direct signal for your intention, and you can see what it does.  If it works, you have a wiring problem or a SBMS0 problem.  If it doesn't work, you have a Quattro problem.

Just as an FYI, I played around with mine, and found that the control is two wires.  One (labeled + I think) is hot, and the other is ground.  The control is activated by taking the hot low, not the low high.  I'm using this to simplify my wiring, since I don't have to run two wires to the Multi (just take the hot, and short to ground as needed).