Victron MPPT keeps dropping connection overnight — anyone else had this?

Had exactly this on my van build about two years back. Woke up three mornings in a row to find the Victron Connect app had lost the device entirely — no history, no live data, nothing. Panels were still charging fine once the sun came up, so it wasn't a system fault as such, just the Bluetooth dropping out like a ghost in the night.

Turned out my SmartSolar 100/30 was going into a low-power sleep state when current dropped to near zero after sunset. The Bluetooth radio was effectively switching off with it.

A few things that sorted it for me:

• Updated the firmware via VictronConnect — there'd been a known BT stability fix in one of the releases around that time
• Checked the load output settings — I had it misconfigured, which was messing with the controller's sleep logic
• Made sure the battery voltage sense was properly wired rather than relying on the internal estimate

Worth checking whether you're seeing this on the SmartSolar or the BlueSolar — the latter obviously has no Bluetooth native, so if you've added a dongle that changes the picture entirely.

Also curious — are you running a Raspberry Pi or any other device polling the VE.Direct port overnight? I experimented with that on my cabin setup and it caused all sorts of odd behaviour with the sleep cycles until I throttled the polling interval right down.

What firmware version are you currently on? That'd help narrow it down pretty quickly.

NoPlanB77 | 📍 Peak District | ⚡ 400Ah LiFePO4 | Posts: 847

@LochWalker Had this exact headache on my narrowboat install. Turned out the Bluetooth timeout setting was the culprit — by default Victron MPPT units will drop BT connection after a set period to conserve power. Check your VictronConnect settings under the device menu, there's an option to keep it active longer.

Also worth checking: if temps dropped overnight, some units get a bit funny below about 5°C and need a firmware update to handle it properly. Connect via USB directly to a laptop and update through VictronConnect — sorted mine completely.

What firmware version are you running? Anything below v1.61 on the SmartSolar range had known Bluetooth stability issues that Victron quietly patched.

Taffy | 📍 Array | ⚡ Emergency Backup & Boat | Posts: 203

Is this specifically the Bluetooth dropping, or is the unit actually losing power overnight? Worth distinguishing because I had something similar on my boat install — turned out the MPPT was browning out briefly when the battery voltage dipped below a certain threshold during load spikes, which caused the Bluetooth module to reset and wipe the recent history buffer.

Have you checked whether there's a corresponding entry in the VictronConnect history showing a low-voltage event around the same time each night? Also curious — are you on the latest firmware? There was a known Bluetooth stability issue on older SmartSolar firmware that Victron quietly patched a while back.

What model MPPT is it, and what's your battery setup? Makes a difference to what's likely causing it.

48V_Pro | 📍 Yorkshire Dales | ⚡ 560Ah LiFePO4 | Posts: 1,204

@LochWalker @Taffy — worth clarifying Taffy's point first, as it changes the fix entirely. If it's purely Bluetooth dropping, that's almost always the MPPT going into a low-power sleep state overnight when there's no solar input. The BT module essentially hibernates.

The workaround that sorted it for me was keeping a small parasitic load on the controller's output — even something trivial like a 1W LED. Keeps it just active enough to maintain the Bluetooth stack.

Alternatively, check your firmware version. Victron quietly patched some BT sleep behaviour around v3.06 on the SmartSolar range. Worth updating via VictronConnect if you haven't recently.

If it's the device disappearing from history entirely rather than just going offline, that's a different kettle of fish and probably worth a separate thread.

George1975 | 📍 Array | ⚡ EV Charging / Shepherds Hut / Van | Posts: 312

Had this on my van build and it drove me absolutely round the bend 😅

Turned out the MPPT was going into low-power mode overnight once the battery hit float and basically the BT module was dozing. Fixed it by enabling "keep Bluetooth enabled" in the VictronConnect device settings — think it's buried under the product settings menu.

Also worth checking your VE.Direct cable if you've got one running to a GX device — if that's solid but BT drops, at least you know the controller itself is fine and it's purely a wireless thing.

@Taffy raises a fair point though — knowing which connection is dropping narrows it down massively before you start poking around randomly like I did for two days 🔧