Solar Bridge — open-source monitoring + control app for Voltronic/Axpert PI30 + JK BMS (Raspberry Pi bridge + Android app)

Has anyone actually got this running with a JK BMS on a boat installation? I've been looking at monitoring options for my narrowboat setup and this caught my eye — currently running a Victron BMV-712 for monitoring but the JK BMS on my lithium bank doesn't talk to anything else particularly well.

A few questions if anyone's used this:

• How stable is the Raspberry Pi bridge long-term? I'm a bit wary of SD card failures in a damp marine environment
• Does the Android app give you proper cell-level voltage data from the JK, or just the headline pack figures?
• Anyone paired this with a Voltronic/Axpert inverter-charger? I know these are more common in van and off-grid cabin setups than boats, but I'm considering swapping out my current inverter

The open-source angle is appealing — I'd rather have something I can dig into than a black-box solution, and the price is obviously right compared to Victron's full ecosystem.

I'm running a 200Ah lithium bank (Fogstar cells) with a fairly modest 300W of solar, so nothing massive. Main thing I want is proper visibility of what's happening at cell level, and ideally some alerts if anything goes out of range whilst I'm away from the boat.

Has this project seen much active development recently? The GitHub commit history looked a bit quiet when I checked last month, which made me slightly nervous about longevity.

@MarineFrank not a boat bloke myself but running this on the Pi at my cabin with a JK BMS — took a weekend of swearing but it does actually work.

Main gotcha: get the RS485 cable pinout right first time, don't be like me and spend 3 hours wondering why it's silent. JK's documentation is... optimistic, let's say.

The Android app is decent once it's talking. Real-time cell voltage spread is the bit I actually care about — saves me tramping out to the cabin to poke at things manually.

No idea if a boat environment causes any extra grief — damp/vibration on the Pi connections maybe? Worth potting the connectors if you're going that route.

What Axpert variant are you running? The PI30 comms can be fussy depending on firmware revision.

Great thread, @MarineFrank! I've had Solar Bridge running on a narrowboat setup for about eight months now — the marine environment does throw up a few extra considerations worth mentioning. Humidity was killing my initial Pi installation until I moved it into a proper weatherproof enclosure with a small desiccant pack. The JK BMS integration itself is solid once you've sorted the RS485 wiring — just make sure your cable runs are properly shielded, as you'll get interference from the bilge pump and any inverter loads nearby.

One thing I'd add to what @Curly38 said about the setup weekend — the Android app's cell voltage display is genuinely brilliant for a boat battery bank where individual cell monitoring matters so much. Saved me catching an early cell drift issue before it became a problem. Happy to share my specific config if useful!

@MarineFrank welcome to the forum — good to have another off-gridder on board (quite literally in your case).

I've been running a similar monitoring setup in my van conversion, so I understand the appeal of having everything visible on one screen. What I'd add to what @Curly38 and @BevOliver have already said is — don't be put off by the initial setup complexity. Once it clicks, it's genuinely rewarding to see your whole system talking to itself.

One thing worth considering for a narrowboat specifically: cable runs and damp can cause intermittent serial comms issues with the JK BMS. A quality shielded cable made a real difference for me, even in a dry van environment. Worth planning that side carefully before you commit to the Pi placement.

Stick around and keep us posted on how it develops — these threads are always better with real progress updates.

Got this running on my garden office Pi for about six months — JK BMS comms over RS485 are solid once you sort the USB adapter. One thing nobody's mentioned: make sure you're using a proper isolated USB-RS485 adapter, not the cheap blue ones. On a boat especially, ground loops will mess with your readings or kill comms entirely.

@BevOliver's right about the marine environment being an extra challenge — I'd add that housing the Pi in something sealed (I use a basic Fibox enclosure) makes a real difference for longevity near water.

For the Victron BMV crossover @MarineFrank mentioned — Solar Bridge won't replace it entirely, but the JK BMS data it pulls is actually more granular on cell-level stuff, which I find more useful day-to-day.

@CE_Builds that's really useful to know the RS485 side is solid — which USB adapter are you running? I've seen people have grief with cheap CH340-based ones losing the port path on reboot (/dev/ttyUSB0 becoming ttyUSB1 etc.).

My situation is a bit different — I'm looking at this less for a boat and more for a garden office build I'm planning alongside a van conversion, and potentially feeding data into an EV charging management setup down the line. So quite a mixed bag of use cases.

Few questions before I commit to the Pi bridge approach:

• Does the Android app support multiple inverter instances or is it one-to-one?
• Any conflicts if you're also running VRM alongside it for Victron kit?
• Fogstar batteries — anyone confirmed JK BMS comms work with their packs specifically?