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

Had exactly this with my SmartSolar 100/30 about eight months ago. Woke up to find the Bluetooth had dropped sometime around 2am and wouldn't reconnect until I physically cycled the unit.

Turned out to be a firmware issue — I was running an older version and the VE.Direct + Bluetooth stack was getting itself into a knot when the panels dropped to zero input overnight. Updating via VictronConnect sorted it almost immediately. Worth checking what version you're on before tearing your hair out.

The other thing worth ruling out is phone Bluetooth interference. I had my phone on charge in the garden office right next to the controller, and occasionally the two would just... fall out with each other. Moving the phone sorted about 30% of my phantom disconnects.

A few questions that might help diagnose yours:

• Is it only overnight, or does it happen during low-light periods too?
• Are you connecting via VE.Direct USB, direct Bluetooth, or through a Cerbo/Venus GX?
• What firmware are you on? (Settings > Product Info in VictronConnect)

If you've got a Cerbo in the mix, there's a known quirk where the Cerbo can basically "claim" the MPPT and boot your phone off. That one needs a priority setting tweak rather than a firmware fix.

Mine's been rock solid since the update — running a 400W array into a Fogstar Drift 200Ah and haven't had a dropout in months. Would be curious whether yours follows the same pattern.

@48VGal what did it turn out to be? Your post seems to have cut off mid-sentence — really frustrating timing given I'm having almost the exact same issue with my SmartSolar 75/15 on my garden office setup!

Mine drops connection somewhere between midnight and 4am, always reconnects fine by morning on its own, but I'm losing that overnight logging data which is annoying when I'm trying to track winter performance.

A few things I'm wondering:

• Could it be temperature-related? My controller is in an uninsulated space
• Is this a firmware issue?
• Does the VictronConnect app version matter here?

Running firmware v1.61 currently — not sure if that's the latest. Anyone know if there's a known bug with the Bluetooth dropping during low/no-load periods overnight?

@48VGal looks like your post got cut off — curious what the fix was.

Had something similar with my SmartSolar 75/15 on the garden office setup. Bluetooth would drop overnight when temps dipped. Turned out to be a firmware issue — updating via VictronConnect sorted it.

Few things worth checking:

• Firmware — make sure it's current, Victron push fixes fairly regularly
• Phone Bluetooth — sometimes it's the app losing connection, not the unit itself
• Interference — any new devices nearby running 2.4GHz?

Also worth trying the VRM portal if you've got a Cerbo or dongle — at least you can still monitor remotely when BT plays up.

@TransitConvert if you're seeing the same, try the firmware route first before pulling your hair out over it.

@48VGal your post cutting off mid-sentence is giving me Victron Bluetooth dropout energy and I'm here for the irony.

@HiluxBuild the irony is chef's kiss, genuinely.

Right, while we wait for @48VGal to finish their sentence (presumably also dropped connection mid-thought), here's what I've seen cause overnight BT dropouts on SmartSolars:

Most likely culprits:

• Firmware — VictronConnect will nag you, but the MPPT itself needs updating separately via the app. Loads of BT stability fixes crept into recent releases
• Keep-alive voltage threshold — if your battery dips below ~11.5V overnight, the unit can enter a low-power state and BT stack goes with it
• Phone doing background app refresh — iOS especially will kill the BT session aggressively

The 2am timing is interesting though — that's typically when a poorly-sized system hits its overnight low. Worth checking your battery voltage logs in VictronConnect history to see if there's a correlation before assuming it's purely a firmware gremlin.

@48VGal @Wez1961 whilst we wait for the Great Reveal — this is a known issue with older firmware on the SmartSolar range. The Bluetooth stack can essentially time out when there's been no active connection for several hours and the unit goes into a low-power idle state.

Worth checking a few things:

• Firmware — VictronConnect should flag if you're not on the latest build
• Keep-alive setting — some people have had success leaving VictronConnect open overnight on a cheap Android device
• VE.Direct to Cerbo — if you're running anything that justifies it, wired comms sidesteps the Bluetooth nonsense entirely

On my garden office setup I had intermittent dropout with a 100/20 until I updated to v3.14 firmware, after which it's been solid for about fourteen months. The Bluetooth hardware itself is rarely the culprit.