Notes on BatteryWatchdog - access to your boat via 4G or Wi-Fi


What BatteryWatchdog can show and How to Use/Interpret It

This demo is running live from our boat (SNAFU II). The boat is on a swinging mooring in the UK - systems powered by solar panels - access via 4G and the VPN. If you are interested in viewing your own boat systems via a VPN, all the software is free and Open Source. We charge a small subscription to enable users to use the VPN. Note that this is a VPN which allows you private access your boat systems, not a VPN to use from the boat for privacy whilst browsing.

Current System
We are running a Raspberry Pi (using a 3B, 4 or 400) which not only supports this BatteryWatchdog but also allows us access to SignalK feeds and Live graphs using Grafana. We utilise Skippers Mate which provides us with other features. Skipper's Mate software is free Open Source and still available for download. We no longer sell hardware because of issues around Brexit but you can source your own hardware - details are available in the extensive documentation.

The software currently supports the more recent Epever MPPT controllers which use Modbus (e.g. Tracer-AN Series) and, from the NASA range, the BM1 battery monitor with Bluetooth connectivity. (See below for more on shunt size.)

Our BatteryWatchdog Setup

This demo shows the current amps and volts via the Epever using our own Open Source BatteryWatchdog gauges.

BM1, BM2 and Shunt
We are using a 200A shunt, not the one provided with the BM1 because of the size of our inverter. So we are running a BM2 head at the chart table so we can glance at the figures when we're in the saloon, and the software has been modified so that the BM1 works with the larger shunt. This is a simple modification which you could make yourself. Just ask if you need to know more.

Epever Triron
This is connected to our 320A of solar panels on deck and to our Raspberry Pi via a RS485 cable.

Our house battery bank is currently 440Ah of lead-acid batteries which are a bit of an unknown quantity since 2 came with the boat when we purchased her in 2020. We also have 2 engine batteries of about 85Ah each which are also charged by the panels. One of the reasons for developing the BatteryWatchdog software is to provide us with more information on the state of the batteries and the performance of the charging systems (solar and alternators). The issue of when we replace batteries and what type of batteries we would choose is a constant topic of conversation, assisted by the gauges and graphs.

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