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

Been running a 100/30 MPPT on my van build for about four months now — two 175W panels in series feeding a 200Ah lithium (a Fogstar Drift, since you're asking). Generally brilliant kit, no complaints about the charging performance itself.

The issue is the Bluetooth. Every few days the controller just vanishes from VictronConnect on my phone (Android 13, Samsung A54). It'll show up briefly when I first open the app, sometimes let me poke around the settings for a minute or two, then drop off entirely. I have to either kill the app, toggle Bluetooth off and on, or in the worst cases restart the phone before it'll reconnect. Bit annoying when you're trying to check your state of charge on a cold morning.

Firmware is current — I updated to v1.61 about six weeks ago and it didn't seem to make any difference either way. I've also tried forgetting the device and re-pairing from scratch. Signal strength shouldn't be the problem; the controller is literally bolted to the wall about 30cm from where I usually sit.

Has anyone cracked this, or is it just a known quirk I need to live with? Wondering if it's an Android compatibility thing or something specific to the 100/30. Keen to hear if iPhone users have the same bother.

@PikeRuss had exactly this on my static caravan setup with a 100/20. Nine times out of ten it was Bluetooth going to sleep after the default idle timeout — Victron's firmware does this aggressively to save power on the MPPT's internal MCU.

Worth checking a couple of things:

• VictronConnect → Device settings → Bluetooth sleep timer — bump this up or disable it entirely
• Make sure you're running the latest firmware on the 100/30 itself; there were some known BLE stability fixes in the v3.1x releases
• If you're on Android, background app battery optimisation will absolutely kill the connection mid-session — whitelist VictronConnect explicitly

Also worth noting: if you've got a GX device (Cerbo, CCGX etc.) on the network, connecting via VRM rather than direct Bluetooth is far more stable for longer monitoring sessions.

DonnaGibson67 | 847 posts | ⭐ Trusted Member

@PikeRuss yes, had exactly this with mine! Turned out my phone's Bluetooth was the culprit rather than the SmartSolar itself — Android has a habit of aggressively killing background Bluetooth connections to save battery. Check your phone's battery optimisation settings and exclude the VictronConnect app from any power saving. Also worth making sure you're running the latest firmware on the MPPT itself (do it through VictronConnect when you do manage to stay connected long enough!).

Mine dropped constantly until I sorted those two things and it's been rock solid since. Similar setup to yours as it happens — van build with a Fogstar battery, though I'm running a 100/20. Cracking bits of kit when they behave themselves! 😄

Yeah had this on my motorhome setup with a 75/15. Worth checking if you've got any other Bluetooth devices nearby competing for the connection — my issue turned out to be my Fogstar BMS and the MPPT both trying to pair at the same time through VictronConnect. App kept dropping mid-session.

Fix that worked for me: disconnect from the BMS first, then connect solely to the MPPT. Also make sure your VictronConnect app is fully up to date — there was a dodgy version a while back that made dropouts way worse.

If none of that helps, try forgetting the device in the app and re-pairing from scratch. Bit annoying but sorted it for me permanently.

GeorgeSmith97 | 203 posts

@PikeRuss worth checking your firmware version on the MPPT itself — I had persistent disconnection issues on my 100/20 until I updated via VictronConnect. There was a known bug in older firmware causing exactly this behaviour. Also, are you on Android or iOS? I found Android particularly temperamental with Victron's Bluetooth implementation. Switching from a budget Android to an iPhone sorted it entirely for me, though I appreciate that's not a cheap fix! One other thing — try toggling the "Stay connected" option within the VictronConnect app settings if you haven't already. It's not obvious but it's there. Good luck with it, cracking little unit once it behaves itself.

PennineVanLifer | 1,204 posts | ⭐ Trusted Member

Something nobody's mentioned yet — check whether your phone is aggressively killing background apps. On Android (particularly Xiaomi/Samsung with their custom battery optimisation layers), VictronConnect gets its Bluetooth thread throttled the moment the screen dims. Go into your battery settings and whitelist VictronConnect explicitly, then disable adaptive battery for it.

Also worth noting: the 100/30 specifically seems to drop connection during bulk-to-absorption transitions when the MPPT is doing rapid internal recalculations. I've seen this on my garden office setup — 400W of panels into a 100/30, feeding a Fogstar 200Ah — and it's almost clockwork at around 80% SOC on a sunny morning. Reconnects within 30 seconds if you just leave it.

If you're on firmware below v1.61, update via VRM or a GX device if you have one — there were documented BLE stability fixes in that release.

Had this exact issue on my cabin setup with a 100/20. Turned out to be the MPPT going into a low-power sleep state during float — Bluetooth basically hibernates. Walk up, panel output near zero on a dull day, and the connection just dies mid-session.

Fix for me was enabling the "keep Bluetooth enabled" option under the device settings in VictronConnect. Drains a tiny bit more from the unit but the connection stays solid.

Also worth noting — if you're using a phone case with magnetic bits (wallet cases etc.) it can mess with the signal more than you'd expect at anything over a couple of metres. Sounds daft but it was part of my problem too.