Orion xs and mppt

Noticed something similar with my setup recently and wondering if others have experienced this.

Running a Victron SmartSolar MPPT alongside an Orion-Tr Smart (non-isolated, for charging from my van's alternator into a 200Ah Fogstar Drift lithium). When the Orion kicks in, the MPPT seems to back right off — solar contribution drops to almost nothing even on a decent day.

From what I can gather, this is actually the BMS and battery chemistry doing their job rather than a fault. The Orion tends to push at a fixed absorption voltage, and once the battery sees that voltage being met, the MPPT simply has nothing left to contribute. Victron's own kit is designed to play nicely together through VE.Smart networking, so in theory they should share the load more intelligently — but in practice I've seen the MPPT yield drop off sharply.

A few things worth checking:

• Are both devices in the same VE.Smart network via Bluetooth?
• What are your charge voltage settings on each? If the Orion is set slightly higher, it'll effectively crowd out the MPPT
• Is your battery actually absorbing or already near full when this happens?

For my garden office setup I mostly rely on solar and only use the vehicle-side charging as a backup, so it's not a disaster — but it did confuse me for a while watching the MPPT flatline on a sunny afternoon.

Would be curious whether tweaking the Orion's voltage ceiling a touch lower helps balance things out. Anyone else fine-tuned this successfully?

@Tina1971 classic DVCC interaction — when both devices are on the same VE.Smart network, the MPPT and Orion can end up fighting over charge state authority, particularly around absorption/float transitions.

Worth checking a few things:

• DVCC enabled or disabled in VictronConnect? If you're running without a Cerbo/GX device, disabling it often resolves priority conflicts
• Are both devices on the same VE.Smart network sharing voltage/temperature sense? If not, they're operating on separate references
• What's your absorption voltage set to on each independently? Mismatched settings cause one to pull the other out of phase

On my narrowboat I run a Cerbo GX which lets DVCC properly coordinate everything — the MPPT defers correctly and the Orion behaves. Without a GX device coordinating things, you sometimes need to offset the Orion's absorption voltage slightly lower than the MPPT so it doesn't "win" the argument.

What firmware versions are both devices running?

@ExSquaddie49 makes a fair point re DVCC but worth checking your absorption voltage settings too — if the Orion's set higher than the MPPT it'll basically be fighting itself.

Had exactly this mess in my static when I first added a second charging source. Ended up with weird voltage spikes confusing the BMS.

Quick things to check:

• Both devices on same VE.Smart network?
• Absorption/float voltages matched across both?
• BMS comms set up properly if you're running lithium?

Honestly Victron's own documentation on multi-charger setups is actually decent for once. The DVCC page on their wiki covers it.

If you're on AGM though, half this probably doesn't apply and it's likely just a settings mismatch.

@Tina1971 what firmware are you running on both units? This caught me out last winter on my shepherd's hut setup — Orion was on an older firmware that had a known bug where it'd ignore the DVCC charge current limit from the network and just do whatever it fancied.

Also, are you using a SmartShunt as the network master? Without a proper BMS or shunt acting as the synchronisation point, the DVCC coordination between the MPPT and Orion is essentially guesswork. Both devices think they're in charge (no pun intended).

Update everything through VictronConnect first, then reconfigure DVCC from scratch — don't just assume your existing settings carried over correctly post-update. They often don't, and Victron's changelog for these firmware versions is characteristically useless for actually explaining what changed.

Good shout from @SolarJunkie on the firmware front — definitely worth checking that first before going down rabbit holes.

One thing nobody's mentioned yet: if you're using a BMS with a shared voltage sense on the VE.Smart network, it can sometimes cause the Orion to receive conflicting charge state information from the MPPT. Effectively the Orion thinks the battery is further into absorption than it actually is and backs off prematurely.

Worth jumping into the VictronConnect app and checking the "history" tab on both devices — you're looking for whether the Orion is cutting out at the same voltage each time or if it's variable. That'll tell you whether it's a settings issue or something more dynamic going on with the network communication. What does your current absorption voltage look like on each device, @Tina1971?

Good points from everyone above. One thing I'd add — have you checked whether your Orion-Tr Smart is actually connected to the same VE.Smart network as the MPPT? If they're sharing battery voltage and temperature data via Bluetooth networking, the Orion should be deferring properly to whatever the MPPT is doing. If that link isn't configured, they're essentially working blind to each other and you can get all sorts of odd charging behaviour. Worth opening the VictronConnect app and confirming both devices appear under the same network. Also, what's your battery chemistry set to on each unit — are they identical? A mismatch there can cause one device to push harder than the other expects. @Tina1971 any chance you could share a screenshot of the VE.Smart network status page?