Victron Orion 30A not reaching full charge on my leisure battery – settings issue?

Had something similar with my Victron Orion-Tr Smart 30A in the motorhome last year. Took ages to figure out what was going on.

Worth checking a few things:

• Are you running it in isolated or non-isolated mode? I had mine configured wrong initially which caused all sorts of weird charging behaviour
• What are your absorption and float voltages set to? The defaults don't always match what your leisure battery actually needs — my Fogstar Drift LiFePO4 needed the profile tweaking significantly from stock settings
• How long are your typical journeys? The Orion won't necessarily reach full charge on shorter runs, it needs time to cycle through bulk → absorption properly

One thing that caught me out was the input voltage threshold. If your alternator voltage drops under load (especially older vehicles), the Orion can keep cutting in and out rather than maintaining a steady charge. You can adjust the input lockout voltage in the VictronConnect app — dropping mine down a couple of volts sorted it.

Also, are you monitoring via VictronConnect? The history tab shows exactly how far into the charge cycle it's getting, which is really useful for diagnosing where it's falling short.

What battery chemistry are you running? Makes a difference to what settings people might suggest. And have you got a BMV or SmartShunt on there so you can see actual state of charge rather than relying on voltage readings alone?

Curious whether anyone else has noticed the default profiles being a bit conservative out of the box — seems like a recurring theme.

@SaltyGrafter — ooh this rings a bell! I had something suspiciously similar on my narrowboat with my Orion-Tr Smart. Turned out mine was cutting out early because the engine battery voltage was dropping under load and the Orion was interpreting that as "starter battery getting nicked, abort mission."

Worth checking your input voltage threshold in the Victron Connect app — mine was set aggressively and would disconnect if the alternator couldn't keep the voltage up properly.

Also, daft question but — have you got a BMS on the leisure side that's occasionally tripping and confusing the Orion into thinking absorption is done when it isn't? Mine had me absolutely baffled for weeks before I realised the Fogstar lithium was throwing a wobble. 🤦

What chemistry is your leisure battery? That changes everything with the absorption settings.

Great points already covered above. One thing neither of you have mentioned yet — check your absorption voltage setting in the Victron Connect app. By default the Orion-Tr Smart ships with fairly conservative presets, and if you're running a LiFePO4 (Fogstar Drift or similar) rather than AGM, those defaults will absolutely undersell the battery.

Also worth verifying: is your starter battery voltage sagging under load while the engine's running? If the input voltage drops below the Orion's threshold mid-cycle, it'll reset the charge algorithm entirely — looks exactly like it's "not reaching full charge" but it's actually restarting repeatedly.

On my narrowboat setup I fixed this by adjusting the start/stop input thresholds in VictronConnect — bumped the start threshold up slightly so it only kicks in when the alternator is genuinely sustaining voltage.

Really good shout from @DevonDweller on the absorption voltage — that's often the culprit. I'd also add: check your tail current setting if you're on a newer firmware. If it's set too high, the charger thinks the battery is full and exits absorption early before it actually is. Victron's default can be a bit aggressive depending on your battery chemistry. AGM and lithium especially need this dialled in properly.

Also worth a quick look at your cable sizing and connections between the units — even a small voltage drop on the input side can cause the Orion to underperform without throwing any obvious errors. Stick a multimeter on both ends while it's running and compare the readings. More than about 0.3V drop and you've likely found your problem.

Good thread. One thing worth adding from my garden office setup — keep an eye on engine running detection. The Orion-Tr Smart uses alternator voltage to detect whether the engine's running, and if your detection threshold is set too high, it'll cut out prematurely before the battery's properly topped up.

You can adjust this in the VictronConnect app under engine detection settings. I had mine set to the default and it kept dropping out on longer float sessions because my van's alternator voltage dipped slightly under load.

Also worth checking — if you've got BMS integration on a lithium battery, make sure the charge enable signal isn't prematurely telling the Orion to back off. Caught me out for weeks before I spotted it in the app's history data.

Really useful thread this — glad I found it.

Quick question that nobody's touched on yet: have you verified what your leisure battery's actual chemistry is rated for? I ask because I've got a Fogstar Drift LiFePO4 in my shepherd's hut build, and I initially had the Orion programmed with AGM voltages — obvious in hindsight, but easy to miss if you've swapped battery types at some point.

Also worth checking: are you monitoring actual battery voltage at the terminal rather than relying solely on the Victron Connect app readings? Voltage drop across connections can make the charger think it's done when it hasn't.

@AlexPalmer60 — good shout on engine detection, that one's caught me out too.

What battery chemistry are you running, and which firmware version is your Orion on? That'd help narrow it down considerably.