Bluetooth Connect/mppt 75/10 - not talking

Had a similar headache getting my Victron MPPT 75/15 to show up in the VictronConnect app when I first wired up the shepherd's hut build last spring. Took me longer than I'd like to admit to sort it.

A few things worth checking if you're in the same boat:

Bluetooth pairing basics first:

• The MPPT needs to be powered — either from the battery or from the PV input. If neither is connected and live, there's nothing to broadcast.
• VictronConnect won't find the device unless your phone's location permissions are enabled (yes, really — it's a Bluetooth LE quirk on Android particularly).

LiFePO4-specific gotcha:
With an Epoch or any lithium battery, if your BMS has disconnected the battery due to a protection event (low voltage, over-temp, etc.), the MPPT loses its power source and simply disappears from Bluetooth. Worth checking the battery voltage directly with a multimeter before assuming the controller is faulty.

What actually fixed mine:
I had the PV and battery terminals the wrong way round in terms of connection order. Always connect battery first, then PV — the 75/10 manual is pretty clear on this but it's easy to rush. Once I corrected that and did a firmware update through VictronConnect (when it finally appeared), everything settled down.

Also worth noting — the Victron SmartSolar range shows up as "SmartSolar HQ..." in the device list, not always by the model number, which confused me initially.

Anyone else running a Victron MPPT with a third-party LiFePO4 like the Epoch? Curious whether others have needed to tweak the charge profile manually or

@WillReid worth checking whether the Bluetooth is actually paired to another device somewhere — phone, tablet, old laptop. The MPPT 75/15 can only hold one active Bluetooth connection at a time, and if something else has grabbed it the app just sits there searching like a muppet.

Had exactly this with my garden office setup. My old phone had paired to the Victron months earlier during testing and was sitting in a drawer still connected. Took me ages to figure out why my new phone couldn't see it.

Force-close VictronConnect, forget the device in your phone's Bluetooth settings entirely, then reconnect fresh. Sometimes you need to do a full PIN reset (000000) to clear it properly if the pairing is really stuck.

@NeilJackson already nabbed the obvious one, so I'll add — my 75/10 refused to show up until I realised the VictronConnect app itself needed updating, not the dongle firmware... spent three days blaming the cable like a complete muppet 🔧

Has anyone tried power-cycling the MPPT itself? I had mine disappear from VictronConnect completely when setting up my garden office system — turned out the charger needed a full disconnect (both PV and battery) for about 30 seconds before Bluetooth would advertise properly again.

Also worth double-checking which version of VictronConnect you're running. There was a period where the app on older Android versions was notoriously flaky with the 75/10 specifically — I had to manually force-update through the Play Store rather than waiting for it to auto-update.

@WillReid did yours eventually pair reliably, or is it still intermittent? Wondering whether intermittent suggests a deeper firmware issue on the unit itself rather than a connectivity/pairing problem.

@Bomber power-cycling is the classic IT crowd solution, isn't it — "have you tried turning it off and on again?" Works on teenagers too, in my experience.

Worth mentioning though: on my narrowboat setup I found the 75/10 has a surprisingly short Bluetooth range, especially through a steel hull. I was standing two feet from the thing