Anyone else running Victron Cerbo GX with multiple MPPT controllers — how are you managing priority charging?

I've got a bit of a head-scratcher in my garden office build. Running two Victron SmartSolar 100/30s in parallel (one on the south-facing roof array, one on a small east-facing panel for morning gain), both talking to a Cerbo GX via VE.Direct. Total array is about 600W feeding a 200Ah Fogstar Drift lithium bank.

The problem is the Cerbo seems to treat both MPPTs as completely independent, and I'm seeing them occasionally "fight" each other during the absorption phase — one drops out while the other pushes ahead, then they swap. Bulk charge times are longer than they should be on a decent sunny morning. I've got ESS running but I'm starting to wonder if that's actually making things worse rather than better for a standalone off-grid setup with no grid connection.

Has anyone actually dialled this in properly, or is the answer just to ditch ESS config entirely and run both MPPTs in standalone mode with shared battery sense? I've seen conflicting advice on the Victron community forum and honestly some of it reads like it was written for a completely different use case (grid-tied yacht with a Quattro, not exactly my situation).

@SmartSolar_Geek mate, the Cerbo GX will just let both MPPTs do their own thing via VE.Direct — they're not actually "priority" charging so much as "whoever's got the most sun wins" charging, which is basically nature's load balancing and honestly works a treat.

If you want actual control, stick them both on VE.Smart Networking so they share battery voltage sense and temperature data, otherwise your east array is effectively flying blind by lunchtime when your south panels are doing the heavy lifting.

My setup with a 100/30 and a 150/35 on separate roof pitches ran chaotically until I sorted the shared sensing — absolute night and day difference on the Cerbo graphs.

@SmartSolar_Geek Running almost identical setup on the boat — two SmartSolars into a Cerbo. What @SaltyMechanic is getting at is essentially correct, but there's more to it.

The bit that actually matters: make sure both controllers are on the same VE.Smart network (Bluetooth mesh), not just VE.Direct into the Cerbo. That way they share voltage sense and temperature data and genuinely coordinate absorption/float transitions rather than fighting each other.

Without that, your east panel controller can drag the south array into float prematurely on a bright morning. Caught me out for weeks before I realised.

Also worth checking your DVCC settings in the Cerbo — enable it, set a system voltage limit, and let the Cerbo arbitrate. It's under Settings > DVCC. Makes a noticeable difference to how the batteries actually finish charging.