How to completely prevent the system from charging the battery from grid

Been having a similar head-scratch with my static caravan setup recently. Running a Victron Multiplus II with a Fogstar Drift 100Ah and I thought I'd locked out grid charging entirely through the ESS settings — turned off the "keep batteries charged" option, disabled the scheduled charging, the lot.

Still catching it pulling from the mains occasionally. 🙄

A few things I've tried that seem to help:

• Setting minimum SOC to 100% temporarily to see what's actually triggering it
• Checking the AC input current limit — even a tiny figure there can let it sneak charge through
• Disabling DVCC overrides in VRM if you're monitoring remotely

What I think is happening is that ESS has its own logic that overrides your manual settings under certain conditions — voltage dropping below a threshold, BMS comms glitch, that sort of thing. Victron's ESS is brilliant but it's got a lot of layers and it's easy to miss one toggle buried three menus deep.

Anyone else found a reliable way to force the system to run purely on solar/battery with zero grid input to the battery? I'm not grid-tied for export, just using the grid as a backup for loads — ideally I want the battery left entirely to the panels.

Would love to know what config others are running, especially if you've got a similar Multiplus II + lithium combo.

@Fiona1974 the Multiplus II will absolutely ignore your ESS "no grid charging" setting and top up the battery anyway if it decides the SOC has dipped below the sustain voltage threshold — sneaky little gremlin that one.

Check your ESS Assistant config specifically:

• Minimum SOC — set this, but also
• Disable "Keep batteries charged" mode if it's lurking in there
• Set Grid setpoint to something sensible

The Fogstar Drift's BMS will happily accept whatever Victron throws at it, so the lockout has to come from the Victron side entirely — your BMS won't save you here.

Remote Console → ESS → Optimised (without BatteryLife) is usually the cleanest mode for full manual control.

@BatteryAlan is right and it caught me out too with my van build when I was testing on hook-up. Worth checking your grid setpoint in VEConfigure as well — if that's set wrong the MP2 basically does what it wants regardless of ESS settings.

Also double-check the minimum SOC setting. Had mine at 20% and the unit kept sneaking in grid charge to maintain it even with "no grid charging" ticked. Dropped it to 0% and the behaviour changed completely.

@Fiona1974 what firmware are you running? Some older versions had a known bug where the ESS assistant just... ignored that preference entirely. Victron pushed a fix a while back.

@Fiona1974 the sneaky culprit is usually the Grid Setpoint in ESS — if it's set too low, the Multiplus just quietly decides your battery is its personal savings account and starts topping it up regardless of what you've told it to do.

@BrookLover nailed the Grid Setpoint angle, but there's another one that bit me badly last autumn — the Scheduled Charging feature hiding in the Venus OS dashboard. I'd completely forgotten I'd enabled it months earlier during a winter test, and it was silently pulling from the grid every night between 2–4am to top up the Fogstar. Took me ages to trace why my overnight grid import was creeping up.

Go into the CCGX or Cerbo interface, find ESS settings, and scroll right down to Scheduled Charging — disable every slot entirely, not just the times. Even a "disabled" slot with odd time values can sometimes misbehave on older firmware.

Also worth double-checking your minimum SOC setting isn't fighting against your intentions.