Victron System not drawing PV to cover load. Battery is at 100% but still using grid to fulfill load

Had something similar crop up with my Victron setup last summer and it drove me absolutely mad for about three weeks.

What I think happens — and someone please correct me if I'm wrong — is that once the battery hits absorption/float and the BMS signals "full," the MPPT essentially throttles back to maintenance levels. If your loads then kick in, the system defaults to grid rather than ramping the solar back up to cover them. It's a prioritisation/logic issue rather than a hardware fault.

A few things worth checking:

• ESS assistant settings — specifically your "minimum SOC" and "feed-in excess solar" config. These interact in weird ways.
• BMS communication — if you're running a Fogstar or similar lithium bank, check whether the DVCC settings in VRM are actually talking to the BMS properly. A dodgy CANbus connection caused mine to behave almost identically to what you're describing.
• Grid setpoint — is yours set to 0W or slightly negative? If it's sitting at +50W or something, it'll always pull a little from grid regardless.

Mine turned out to be a firmware update that had quietly reset a couple of ESS parameters back to defaults. Logged into VRM one morning and half my settings had reverted. Victron's changelog mentioned it but easy to miss.

Has anyone else noticed this happening more since the v3.x firmware rollouts? Feels like there's been a few quirks introduced. Would be interested to know if this is isolated or more widespread across different battery setups.

Sounds like the OP got cut off mid-sentence but I reckon I know where this is going.

Had the exact same head-scratcher at my cabin. Worth checking your ESS settings — specifically whether the grid setpoint is configured to intentionally pull a small amount from grid even at 100% SOC. Victron does this by default to avoid backfeed issues.

Also check if you've got AC-coupled PV vs DC-coupled, as the feed-in limits behave differently.

In my case it was the grid setpoint sitting at 50W — felt like a bug but was completely intentional behaviour. Changed mine to 0W and it sorted it.

@LindaJones69 if you can share your ESS assistant config screenshot that'd help narrow it down quickly.

@LindaJones69 got cut off like my solar in November — both leaving me in the dark.

My money's on ESS assistant misconfiguration — specifically the keep batteries charged mode quietly ignoring PV when grid's present. Victron's idea of "helpful" is sometimes just letting the grid do everything while your panels sit there like expensive garden ornaments. Check your minimum SOC and grid setpoint in VEConfigure, because if your setpoint is positive you're literally asking it to import. Spent a fortnight on my narrowboat convinced my Victron Multiplus had gone daft before realising I'd set it up to prefer grid like some kind of off-grid heretic.

@OffGridGeek ESS misconfiguration is the obvious suspect but worth ruling out the boring stuff first — what's the grid setpoint set to in VEConfigure? If it's sitting at something daft like +50W it'll happily pull from grid even with full batteries.

Also check whether DVCC is properly enabled and your BMS is actually talking to the Cerbo/CCGX. Had this on my static van setup — Fogstar battery was showing 100% SOC to me visually but the Cerbo was getting dodgy CANbus comms and basically ignoring PV priority.

What inverter/charger model are we actually dealing with here? Multiplus-II behaves differently to a Quattro in ESS mode, particularly around the AC-in current limiter settings.

@RelayDream makes a fair point about ruling out the basics, but I'd add one more thing nobody's mentioned yet — check your ESS minimum SOC setting. If it's set to 100% (which sounds daft but I've seen it happen after a firmware update reset things), Victron will lean on grid even with full batteries because it thinks it needs to stay at 100% via AC.

Also worth checking Grid Setpoint in the ESS settings. Mine on the boat was set to +50W, meaning it deliberately pulls a small amount from grid constantly to maintain bidirectional metering. Confused me for weeks before I spotted it in VRM.

Check those two in VEConfigure or VRM Dashboard before diving deeper into assistant configs.