Had this exact issue on my van build last winter. Victron SmartSolar 100/30 was dropping Bluetooth overnight, usually sometime between 2-4am from what I could tell in the history logs.
Turned out to be a combination of two things for me:
- Firmware - hadn't updated in ages. The VictronConnect app kept nagging me and I kept ignoring it like an idiot. Updated to the latest and it helped massively.
- Temperature - my controller is mounted inside the van near the rear doors and it was getting properly cold overnight. Not cold enough to cause damage, but apparently enough to cause some instability with the Bluetooth chip specifically.
Added a small piece of closed-cell foam insulation behind the unit and the dropouts reduced significantly after that.
Still get the occasional blip if it drops below about -5°C but that's pretty rare even parked up on Dartmoor in January.
Worth checking a few things:
- What firmware version are you running?
- Is your phone/tablet going into aggressive battery saving mode and killing the BT connection from that end rather than the MPPT?
- Any other BT devices nearby causing interference? My old Fogstar battery monitor was chattering away constantly and I think it was causing grief
The VRM portal is also worth setting up if you haven't already - gives you much better visibility of exactly when the drops are happening rather than relying on the onboard history which is fairly limited.
What controller model is it and how old is the unit? Might be relevant if others have had similar.
