You will have received 6 modules and some cables. Let’s locate the modules and see what they do. First, the programmer:

The programmer module

The programmer, or PG as we’ll call it from here on in, is used to upgrade the other modules. The PG is in a small enclosure, has a display and a cable coming out with a 5 pin connector on the end (actually a 6 pin header with 1 pin missing to prevent it from being inserted the wrong way around). It does not require batteries or other external power because it is powered from the module you plug it in to.

When we produce bug fixes or functionality updates for modules you’ll use the PG to upgrade those modules.

The environmentals module

The environmentals module, which we call TPH, short for “Temperature Pressure and Humidity”,  monitors exactly that, air temperature, pressure and humidity. This can be powered either from your 12VDC bus or from 2 AA batteries.

The TPH has another important function, which is acting as a network relay. All SharksHead modules communicate via radio (in the 2.4GHz band, same as WIFI or 802.11b) at a very low power level. Hence bulkheads or other structures on a boat can block signals from getting to their intended destination. We’ll discuss this in more detail later but put simply, if your modules have trouble communicating, you may be able to get things working more reliably by placing the TPH module where both sides can “see” the TPH and hence they can resume full communication.

As an example, on our steel test vessel, one battery controller is located in the forward chain locker (behind a steel bulkhead) to monitor the dedicated windlass battery. To improve connectivity,  we have hence installed the TPH module in the salon, which is half-way to the wheel house where the headquarters are located. The TPH module can then act as an intermediate router for all the modules that are forward of it while at the same time reporting its own sensor data back.

The consumer controller

The consumer controller, or CC for short, is designed to monitor the current (and power and energy) used by things like your radio, GPS and other navigation equipment but also cabin lights, bilge pumps, etc. Any 12VDC device that uses up to 8A. Draw more than 8A and it will trip its (virtual) circuit breaker.

The CC can also be used to remotely turn said devices on and off via the web interface. In other words, given enough CCs you can replace (or extend) your existing DC breaker panel.

The battery controller

BC front view

The battery controller, or BC, sits between your battery positive and your bus positive, in-line or in series. It contains a latching relay so you can connect or disconnect the battery from the bus without drawing any power to keep the relay energised.

It measures voltage on each side of the relay and it measures the current (and hence power and energy) flowing in to or out of the battery. It also measures the temperature of the battery and its own internal temperature and reports everything back to the headquarters.

As these values can be shown as a graph days or even weeks later, it allows you to compare and verify the charge profile that was actually applied to your battery with the recommended charge profile and thresholds suggested by the manufacturer of your batteries. If there is a discrepancy, you can subsequently adust the settings on your battery charger(s), if they allow that, or get a more versatile charger.

Case at hand is our own test vessel which was fitted with six 70 Ah Marathon AGM batteries but only had a simple 2 phase solar charge controller that dropped from bulk charging straight into absorbtion mode as soon as the bus voltage reached the fixed threshold. At that point, the batteries were only 80% full. This effectively killed the batteries within less than two years.

The Watt-hour (Wh) and Ampere-hour (Ah) bars can provide the following information:

  • overall battery health by comparing the bars with other batteries
  • charge efficiency, by comparing Ah in vs Ah out
  • battery capacity by disconnecting all other batteries and let this one discharge to 0% (which might equate to 10.5V on some LA batts). Make sure to charge it back up immediately, which will start happening as soon as the other batts are coming online again
  • State-of-charge (SOC): once you know the real capacity the graph will show you how

Being able to disconnect each battery from the bus individually is one of the most intriguing features of SharksHead as:

  • it allows the mix of different battery chemistries, like some classic lead-acid batteries, AGM batteries and even LiFePo4 (LFP) batteries on the same bus
  • it allows to direct the charge current to individual batteries
  • it allows discharging of individual batteries for capacity or health testing
  • it allows separating a battery from the bus for maintenance or replacement
  • it allows separating a battery from the bus for extended periods in order to check the self-discharge rate of a battery
  • it allows the detection of weak or shorted batteries

and many more things we haven’t even thought about. Well, that’s where you come in: our users.

The Headquarters

The HQ is where it all comes together. It is the central hub of the entire system. All modules communicate exclusively with the HQ, you communicate exclusively with the HQ, all data is stored on the HQ, the HQ analyses and acts on the received data to provide services such as alarms, and the HQ sends a real-time stream of data back to you and every other user accessing the HQ. Yes, you can have as many users (or browsers) as you want logged in at the same time.

On the next page we’ll describe how to set it all up.