Hi, I have a full 12 volts Victron System in a Van. Multiplus II, Cerbo GX with touch display , BMS-2, Orion Dc-Dc for controlling output DC voltage, battery protect, SmartShunt, 2X 12V 330 AH Victron SmartLithium batteries and a MPPT 100/50 to control PV input from external solar panel. PV is connected to the MPPT and it is charging the batteries, but even when the Touch Display shows the batteires at 100% SOC since a few days in a row (without any load connected to the system during these days, so no significant drain to the batterie, only the Victron equipment above), MPPT is not going into absorption nor float, always stays in bulk mode. Batteries are going into absorption and float when charged from grid connected to the Multiplus though, but not when charged from the MPPT. Parameters in the MPPT are Absorption Voltage to 14.2V, Float voltage to 13.5V (default parameters for the SmartLithium Batteries Setting, and as per batteries manual, 13.5 is the specified Float voltage, but I can’t find the specified absorption voltage for the 330AH Victron LiFePo4 battery). When looking at the MPPT details in the Victron Connect app, on the PV side I see voltage (35-40 volts, which is OK for the PV) as well as current, again in spec with the panel specifications, and on the batteries side I see around 13.58 volts and the equivalent PV current for this voltage at 100% SOC. But MPPT always stays in « Bulk ». I don’t see why the MPPT would not go into absorption and float afterwards but keeps staying in Bulk. Any thoughts?
14.2V is the correct absorption voltage for the Smart Lithium batteries.
The MPPT will be under DVCC control and in this case only shows bulk, mine does this under DVCC control. If it was in true bulk it would not have reduced to the float setting of 13.5V.
Thanks so much! This is interesting, since the installer has not checked the DVCC option in the GX parameters. DVCC is currently unchecked. So am I OK to understand that the Cerbo cannot be the one controlling the MPPT in this case?
If you have a look in VictronConnect and the SCC State says “bulk” (or Absorb or Float) then the SCC is definitely not being controlled by the GX - if it were, it would be “External Control”.
i have the same probleme, maybe someone solve it? thx!
You have a number of devices being powered by your batteries even when no loads are attached. Collectively their idle power draw is likely around 10W so 0.24 kWh per day.
Then you have over 600 Ah battery capacity to be charged. You didn’t say how much PV power you have hooked up to it but if batteries are depleted this could take a few days to charge up.
Charging is working on ac power so the batteries seem to be OK. On solar it is not going to go from bulk into absorption until the input voltage reaches 14.2V (Your current settings).
Parasitic loads, weak solar, a bad connection or a setting somewhere is preventing the PV from fully charging the batteries
It finally resolved itself. It took 4-5 more days with 500 watts of solar and clear sky before the MPPT stopped charging and went into float. Since then, I have discovered that when solar charging, seeing 100% SOC on your screen does not necessarily mean that the batteries are fully charged. SOC drifts when charging with the solar panel for a period of time because of variations in the solar panel charge voltage due to clouds, etc. I have to fully charge the batteries via shore power from time to time to ensure the SOC comes back to a more exact number. This solar charge behaviour is documented.
The SmartShunt SOC going prematurely to 100% is well.known and can be sorted out to stop this happening, it is usually because the “charhed voltage” setting in the SmartShunt is too low. See