Overengineering power monitoring on yacht

I'm living on my yacht and I wish I could just leave things alone or just buy an off the shelf device and let it monitor the battery and be done. But, where's the fun in that? In a nerdy way I enjoy tinkering with this.

My question is what devices are available?

The project:

It started with wanting to know how much power the wind turbine was generating. The solar controllers have ports where data can be accessed but inconvenient to look in the cupboard at the basic display.

I thought I could add a current meter to the wind gen circuit (30A acs712) and get the data from the solar controllers with an esp32. Current isn't enough to measure power so I used a 3 channel INA3221 current and voltage monitor. It has some inaccuracies but 1% error may not really matter.

Counting power turned into relearning riemann sums to estimate power at time interval readings. Then somehow storing that information so I could get data like readings over the last hour, last 24 hours and total power generated. It feels like I'm reinventing the wheel though.

Because I wanted to overengineer things, I'd like to add monitoring to the distribution panel to see where power is going such as fridge, laptop, lights and alternator power. Plus an overall battery monitor to estimate state of charge.

The house bank is 12V 270Ah lithium and engine lead acid. There may be up to 100 amps from lithium and whatever spike engine starters generate.

At the moment there's just a very inaccurate analog meter showing current and volts through the distribution panel only. Charging, alternator, engine battery circuits are unmonitored.

I started looking at various battery fuel gauge ICs and seeing what projects are on github but perhaps people can shortcut my research with their knowledge.

I have had a similar project. My project does monitor the current charge status of several batteries were distributed over the sailing yacht. Each batterie has their own slave computer doing the sensor data collection and related calculation tasks, I like Rieman. A master is polling for the current charge status via a radio link and a tablet is showing these values.

That seems like a lot of power usage. It depends on your solar generation. I'm trying to keep it low as practical.

Multiple INA3221 current/voltage monitors can be fed back to a central location via I2C bus. Works fine with my ethernet cable test. That saves power rather than multiple computers with radio signals.

But doing the calculations then any SoC for the battery seems like reinventing things that I'm sure there would be devices for already. With maths that starts to be a bit time consuming to implement personally.

the radio link was a costumer request to avoid additional cables.

There is a power monitor for up to 100a one can get on Ebay etc. for a few dollars.
Used to monitor dc motors in r/c gear.

I understand there are basic watt meters and cheap battery monitors available but multiple circuit monitoring isn't available. Or it's at a very high cost. Then there's an ugly black box lcd device that has no specs. I mean the INA3221 boards are very inexpensive and can get voltage/current readings on 3 channels.

So, the ones I pointed to are cheap enough so buy however many you need for your multiple monitor.


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Yes, I've seen exactly that. Cheap enough. The problem is that they are inline and end up under the bed and hard to access. It would be amazing to have a blynk style dashboard app up on the distribution panel with a touch screen to view things.

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