Feat: Battery BMS and Solar Charger Widget

[godind]

Both widgets should work on the same framework where you can select individual instances and group them to display banks total and individual component values.

Data

Battery (BMS) should use all individual items values under /vessels/<RegExp>/electrical/batteries/<RegExp> and offer a grouping/bank view:

• Bank amp capacity
• Bank amps total consumption (-45amps)
• Bank remaining capacity (amps %)
• Bank remaining time
• Bank current( Amps and Watts flow in/out) *add visual cue for flow direction

Solar Charger/Controller should display everything under /vessels/<RegExp>/electrical/solar/<RegExp> and group values:

• Chargers current (Amps flow out)
• Panels current (cumulative Amps flow in)
• Load port name
• Load port current (Amps out)

Visual cues

• Have a visual indicator that only acts on charging/discharging., such as a lightning for charging and a lightbulb for discharging.

[godind]

To anyone reading this, I would love to have a Signal K stream file containing a good lithium and solar setup (cells, BMS, chargers, solar, etc.) that is visible in Signal K paths, so I can visualize while I design the widget. Get in touch if you don't know how to generate one but have the setup.

[svlibertine]

I'm happy to provide lithium data from my Victron system (Lynx BMS, Lithium Battery Smart batteries, Multiplus II inverter chargers / Cerbo GX). Unfortunately my solar system is offline for another couple of months. I'll need some pointers how to generate the file.

[godind]

First you need to enable Data Logging on each Data Connections feeding the server. Seconds you need to set the Data Logging Directory.

Make sure to either turn off the Keep only the most recent data log file, or set the retention period long enough for you to grad the file.

Let it run so we get some data (create hourly log files), ideally within a period where there is activity like discharging and charging.

Send the log file over.

[svlibertine]

Got it. I'll capture some activity and send the log file over.

[svlibertine]

Here we go.

Filename ends in '16.log'. This is local time. 14:00 - 15:00 UTC should be in the file.

Some simple notes what was happening during the hour if it is of any assistance:

14:00 UTC - Start of log. Genset running, 5KW AC draw and 3KW battery charging
14:15 UTC - Turning off AC draws and charging. Stop genset
14:20 UTC - 3KW AC inverter draw, no charge source
14:30 UTC - Start engine
14:40 UTC - House bank alternator on (WakeSpeed charge controller connected to VE.Can/N2K bus) - 3.5KW
14.50 UTC - Engine off
14.55 UTC - Shore power charging

Times are approximate.

skserver-raw_2026-02-06T16.log.zip

[godind]

Fantastic. I'm finishing a AIS widget (big job!) and If I don't get pressure to do historical data for the Data Chart, I'll work on it.

[svlibertine]

Awesome! Looking forward to test when the time comes :)

[godind]

@svlibertine Hi. Trying your stream file. I see 3 batteries only:

I don't know if it's intentional but you have two batteries (sources really) sending to the same paths. See bat_solar.225 and bat_solar.41. Id 225 is sending only voltage and current. Both are fighting over current but luckily, they send the same voltage.

In any case, I don't think this is right. Check your setup. If you have multiple sources sending to the same path, you will have erratic data.