Anyone using Mopeka Pro 200B?

Been trying to sort out gas monitoring on the boat and picked up a Mopeka Pro 200B recently — the battery-powered variant rather than the wired version. Seemed like the sensible choice given I didn't want to run cables to the gas locker.

The thing is, I already have a couple of Mopeka sensors running fine (including a standard Pro 200), plus a few Ruuvi tags dotted around for temperature/humidity. All of those show up reliably in Home Assistant via Bluetooth. The 200B though? Barely getting a reading — it's either not appearing at all or dropping out constantly, even though it's physically closer to my ESP32 Bluetooth proxy than some of the others.

From what I can tell the "B" suffix just means battery-powered, so I'd assumed it would behave identically on the software side. But something seems off.

A few specific questions:

• Has anyone actually got the Pro 200B working in HA or similar setups?
• Is there a different BLE advertisement format compared to the wired version, or does it need a different integration/device config?
• Could it be a firmware issue on a newly shipped unit?

Worth mentioning my setup is a 12V narrowboat system — Victron Cerbo GX as the main hub but I'm handling the tank/sensor stuff separately through HA running on a Pi. The other Mopeka just feeds straight in without fuss.

Not sure if this is a known quirk with the "B" variant or if I've just got a dodgy unit. Would appreciate hearing from anyone who's actually deployed one before I go down the returns route.

Hey @RobBennett93, good shout going battery-powered on a boat — the last thing you want is running signal wires anywhere near a gas locker. The 200B pairs nicely with the Mopeka app over Bluetooth, but worth noting the range can be a bit temperamental through steel hulls. If you're finding connectivity patchy, try positioning your phone or tablet closer to the locker when checking levels rather than relying on it passively updating from the cabin. Also make sure you've got the sensor calibrated correctly for your specific cylinder type — propane versus butane affects the ultrasonic readings. What cylinders are you running? That'll help narrow down whether the default settings will work out of the box for you.

Ran one of these on my tiny house build for about eight months now — rock solid. One thing worth knowing: the Bluetooth range can be a bit flaky through steel/aluminium if your LPG locker is tucked away. I ended up using the Mopeka Tank Check app alongside it and found pairing worked better once I updated the firmware via the app first before mounting it permanently.

Also worth checking your tank is actually compatible — the 200B is calibrated for specific cylinder profiles. UK Calor butane and propane cylinders generally work fine but the readings can drift slightly on older dented tanks. Give the sensor a clean mount on the base with no air gaps, that sorted my intermittent readings.

@RobBennett93 got one zip-tied to my propane tank in the van and the Mopeka app is genuinely the only reason I haven't been caught out mid-brew on a cold motorway layby — calibration tip though: make sure you set the fluid type correctly in the app or it'll read like your tank is perpetually half-full, which sounds great until it isn't. 🥶

Also worth noting the CR2032 battery life is decent but swap it before winter if you're living aboard — cold kills coin cells faster than a British summer kills optimism.

Got one on my shepherds hut — been running it through winter which is the real test. Cold nights do seem to affect the ultrasonic readings slightly, Mopeka compensate for temperature but I'd still treat the lower end of the gauge as approximate rather than gospel.

Worth noting the CR2032 batteries don't last as long as advertised in my experience, particularly if you're polling frequently. Keep a few spares handy.

One thing nobody's mentioned: make sure the magnet contact on the base is actually clean before fitting. Mine gave erratic readings for a week before I realised there was a thin layer of surface rust on the tank bottom throwing it off. Gave it a light sand and it's been solid since.

Good timing on this thread — running a Mopeka Pro 200B on my tiny house setup for backup heating monitoring and it integrates beautifully with Victron Cerbo GX via the Bluetooth scanner if anyone's gone down that route. You get tank level sitting right there in VRM alongside your battery state, which is genuinely useful for remote monitoring.

One thing nobody's mentioned: magnet placement matters more than you'd think on curved tanks. Worth spending five minutes with the calibration wizard rather than just slapping it on and hoping. Got wildly inaccurate readings initially until I re-ran the setup properly with the tank at a known level.

@ExPostie the cold affecting ultrasound readings is a known thing — the sensor compensates to a degree but LPG density shifts with temperature so some variance is expected, not necessarily a fault.

Had one on the narrowboat for a couple of seasons now. Magnet mount is brilliant when you're swapping cylinders at a marina — no faff, just slap it on the new one.

Only gripe: signal can get a bit wobbly if the tank's tucked right in the back of a gas locker with steel sides. Worth checking your Bluetooth range before you rely on it properly.

@ExPostie — yeah the cold readings thing is real. Propane especially, because the pressure drops off a cliff when it's freezing and the sensor can get confused. I've learned to just physically check the weight of the cylinder in January rather than trust the percentage blindly.

Overall though, decent bit of kit for the money. Pairs nicely with a tablet running in the wheelhouse so I can glance at levels without crawling into the locker every five minutes.