Anyone else had grief with a Victron SmartSolar 100/30 dropping connection to the VictronConnect app mid-charge?

Been having a frustrating one this week. My SmartSolar 100/30 keeps losing Bluetooth connection to VictronConnect on my Android phone (Samsung S21, latest app version) usually around midday when it's pushing out peak amps. I'll be watching the dashboard, everything looks fine — 28-30A coming in from my 400W panel array — and then it just drops. Reconnecting is hit or miss, sometimes takes 5 minutes of toggling Bluetooth on and off.

It's not the end of the world because the controller obviously carries on doing its job, but I like keeping an eye on the yield data and it's a bit annoying losing chunks of the history log. I'm running a 12V 200Ah lithium (Fogstar Drift) and the MPPT itself is only about 8 months old, firmware is up to date (v3.14).

Has anyone seen this with the 100/30 specifically, or is it more of a general Victron BT issue? I've seen a few mentions of interference from inverters causing problems — I've got a Giandel 2000W pure sine running off the same bank, wonder if that's relevant. Any fixes that actually worked would be brilliant.

@PeteDixon89 had this exact issue with mine last summer. Turns out it was the MPPT working flat out at peak solar — the BT radio seems to get flaky when the unit's thermally loaded. Mine's mounted in my garden office and was getting direct sun on the casing, which didn't help.

Few things worth trying:

• Shade the unit if it's in direct sunlight
• Check you're within about 10m with no obstacles
• Try the "forget device" option in VictronConnect and re-pair

Also worth updating the firmware via the app when you do manage to connect — there were some BT stability fixes pushed out a while back.

Mine's been solid since I moved it out of direct sun and updated firmware. Probably thermal throttling causing the dropout rather than anything seriously wrong.

Hey @PeteDixon89 — worth checking whether it's actually a thermal thing causing the BT module to play up rather than just the MPPT being busy. Mine did something similar and I found that even a bit of extra ventilation around the unit made a difference. Also, have you tried switching off battery optimisation for VictronConnect in your Android settings? Samsung in particular is quite aggressive about throttling background connections, and it can absolutely cause mid-session dropouts. Go to Settings > Apps > VictronConnect > Battery > set to "Unrestricted." Made a noticeable difference for me. If neither of those helps, it might be worth doing a full firmware update via VE.Direct if you haven't recently — there were some BT stability fixes in recent releases. What firmware version are you currently running? 🔧

Mine did the same on the narrowboat — turns out my phone was auto-connecting to the engine panel's Bluetooth at peak solar hours like some kind of nautical saboteur, nothing wrong with the Victron at all.

Really interesting one this. @PeteDixon89 — worth double-checking your VictronConnect app's "Stay connected" setting if you haven't already, as Android can be aggressive about dropping background Bluetooth to save battery, especially when the screen's been off a while. Also, if you've got a GX device or anything else Victron on the network, the MPPT will prioritise that VE.Direct connection over Bluetooth when it's busy processing. Might explain the midday timing specifically when charge current is peaking. Try going into your phone's battery optimisation settings and excluding VictronConnect entirely — made a noticeable difference on my old OnePlus. What firmware version is the MPPT running? There were some BT stability improvements in recent updates worth checking.

Good shout from @JennyParker on the thermal angle — worth adding that the 100/30's BT antenna is right inside the main housing, so if it's mounted in an enclosed space or getting direct sun, the module can throttle/drop out before the thermal cutoff does anything obvious.

Also seen this pattern with Android specifically — Samsung's battery optimisation is brutal and will kill background BT processes exactly when the phone's screen dims. Go to:

Settings > Battery > App optimisation > VictronConnect > Unrestricted

Done this on my own setup and it basically eliminated the mid-session dropouts I was getting while monitoring my EV charging sessions.

If neither fixes it, grab the VRM portal dongle — takes BT out of the equation entirely and you get proper logging too.

Just chiming in from my own experience with something similar — have you checked whether your phone's battery optimisation settings are killing the Bluetooth connection? On Android (especially Samsung), the aggressive battery management will often throttle background apps around midday when your phone's been on for a while. Go into Settings > Apps > VictronConnect and make sure it's excluded from battery optimisation entirely. Made a noticeable difference for me. Also worth checking if your phone is dropping to 4G/5G data at peak times and somehow interrupting things — sounds daft but I've seen it cause odd behaviour. @Slim13's point about the Stay Connected setting is a good one too, make sure that's definitely toggled on. Hope you get it sorted! 🙂