Thursday, 23 June 2022

Port Louis Week 3

Hi everyone,

We've now been in Port Louis Marina in Grenada for about three weeks.  The time has flown.  Lots of boat jobs completed, some fun with cruiser pals and some local exploring.

Grenadian sunset

Our first few days were consumed with fitting our new Lifeline Lithium batteries as previously posted.  We also explored the marina and the local area.  High on the agenda in the marina were the showers and the pool.  Both are very nice indeed!  The Victory Bar in the marina is a nice restaurant with friendly staff.  There's a very nice bakery on the access road into the marina.  And the nearest supermarket, only a 5 minute walk away, is pretty good.

Marina office

The pool

The Merry Bakery

We walked into St George's for a look around the national capital.  It's a 20 minute walk around the bay.  Some of the architecture in St George's is early Victorian and quite impressive.  The local boats moored around the edge of the bay are very colourful.

View across the bay while walking to St George's

Colourful local boats

From the town we walked up the hill to Fort George.  Nice views.  The fort houses the Police Headquarters and the Police training academy, but tourists are welcome to look around.  A tour guide certainly helped finding some of the better hidden parts of the fort.

View from Fort George

Exterior of Fort George

View of Port Louis Marina from Fort George

Canons at Fort George

The US invasion of Grenada followed the shooting of the previous Prime Minister Maurice Bishop and others.  Their imprisonment and execution took place in the fort and the bullet marks can still be seen in the wall near a plaque.

Plaque commemorating those shot in 1983 at Fort George

Fort George tunnels

A group of OCC yachts were in Port Louis Marina together, with some also anchored in Prickly Bay.  We all met at the West Indies Brewing Company for dinner.  Twas a great night with the crews of Ari, Cerulean, Favourita, Walkabout, and Zelda. 

West Indies Brewing Company bar

West Indies Brewing Company loos - with repurposed kegs

More recently we walked to the top of a nearby hill with Chris of Aussie sv Ari.  Good exercise and great views from the top.

Relaxing after the hill climb

View north over the marina

View to the south

In amongst all the above we've completed a number of maintenance tasks:
  • Replaced old AGM batteries with new Lithium (described here)
  • Replaced old battery chargers with Lithium compatible chargers
  • Rearranged circuit breakers on the instrument panel
  • Cleaned, inspected and remarked the anchor chain, removing several rusting links
  • Applied patches to wear spots on the mainsail
  • Stitched canvas patch onto the goalpost canvas rain catcher to improve its efficiency
  • Oiled the on-deck woodwork
  • Cleaned and stowed the SailingGen hydro generator and Torqeedo electric outboard
We also got help from local company Triple Services to repair our fridge.  Over the previous few months it had become unreliable - turning into a freezer for a few days then not working at all for a similar period.  Tevin of Triple Services came down with his crew and fixed it in a couple of hours.  The moisture filter was replaced and the system regassed.

Tevin of Triple Services fixing the fridge

We're carefully monitoring and testing our new battery system.  It is connected into our SignalK system which records all the data.  The graph below shows a week of testing starting with 3 days running on solar only, then charging with the mains charger, then 3 days of the mains charger 'topping up' the batteries occasionally.  A brief engine run is in there too - shown by the orange Start Battery Voltage trace 'spiking' in the top graph.  So far so good!

A week of battery trials

Trust all's well where you are.

Friday, 17 June 2022

Reducing Single-use Plastic Usage To Help Our Oceans

 As sailors, we are all too aware of the need to reduce our usage of plastics, having seen first-hand the terrible impact on our marine life. Plastic has touched practically every corner of the planet - even in the Cocos-Keeling Islands, we found the windward coast littered with trash. We often saw floating plastic debris when we crossed the Indian and Atlantic oceans, so the problem is real and pressing.

Today, there is an increasing awareness of the urgent need to reduce our dependence on single-use plastics. A recent ban on single-use plastic bags and plastic drinking straws in some countries illustrates this trend. We have made small but important steps on our way to eliminating plastic waste, but we still have a long way to go. 

Furthermore, in many of the less developed countries we have visited, reducing plastic usage is particularly important. Although some great work is being done by various organisations, many countries lack the resources and infrastructure for recycling. Because of this, it is even more important to not add to the growing piles of plastic waste in landfills.

This post describes some of the strategies we have used but this is in no way exhaustive and I would welcome any further comments or ideas!

Essentially our strategy boils down into 3 parts:

  • Minimise usage

  • Recycle and re-use

  • Substitution

I’ll go into each step in turn……

Minimise Usage

If I can’t avoid purchasing an item without plastic packaging, I’ll buy the largest container that fits in our lockers , and repack the contents into smaller containers for immediate use. I do this for bulk pasta, rice, pulses, cooking oil, and even toiletries such as moisturisers and lotions.

Repacking dry goods for short and long term use

In this way, I’m only buying one large container rather than several smaller ones, and where possible, I will re-use these containers when empty.  Which leads to my next step….

Recycle and reuse

If I can find a way or re-using a container or a bag, I will! Many foodstuffs come in sturdy re-sealable bags and I will re-use these again and again to store anything from sandwiches for a passage to flour and powdered milk. Strong plastic bottles work well for storing cleaning fluids (for some ideas on environmentally-friendly cleaning tips, please see my last post!).

Old sauce bottles work well for kitchen use
I'm storing tortillas in this reusable bag

Some countries offer recycling facilities, so where they are available, we make sure we recycle whatever we can.

Finally, we’ve found that some vendors are happy for us to return their packaging to them so they can use it again.

Not only does Mandingo sell wonderful tropical fruits, but he accepts empty bags to re-use. What a legend!


The third step is to find an appropriate alternative to plastic, which is the best option as we avoid using plastic at all. Some examples include:

Using multi-use bags when shopping: many people now do this as a matter of course, and we are no exception. Many Caribbean fresh food markets sell their produce in plastic bags, so I bring my own bags to use instead. I’ve had them for many years but they’re starting to look a little worn, so I’m also going to make some more bags out of scraps from my huge fabric stash!

It goes without saying that if we can buy items loose or in a more environmentally friendly package, we will do this. The wonderful medina in Monastir sold all dry goods completely loose, so we could buy oats, beautiful dried fruits and almonds to make our muesli.

No packaging here!

Making your own: by making our own yogurt, muesli etc., we don’t need to purchase them at the store in their plastic packaging.

Making muesli in bulk

Plastic free alternatives: it’s possible to source all sorts of biodegradable personal care accessories, such as bamboo toothbrushes, biodegradable dental floss, laundry detergents and kitchen sponges. We’ve made use of all of these, along with re-usable and washable sanitary products. Even in countries where it isn’t as easy to find such products, there may be local alternatives. For example, we learned from our wonderful OCC Port Captain Martin that coconut coir can be used as a pot scourer and lasts for several months!

Our bamboo toothbrushes - but check carefully if the bristles are also biodegradable

Despite our best efforts, we’ve found that we still can’t completely avoid single-use plastic. There are times when I open a packet of teabags or crackers and discover that every single one comes individually wrapped in plastic (why???!!!)! But by following these steps, we’ve tried to minimise our plastic ‘footprint’ as best we can and I hope that you find these tips useful.

I’d also be really interested to hear any other thoughts or ideas about how others reduce their plastics use - feel free to comment below!

My next article will explain a few ways of minimising fuel and water consumption when I cook so stay tuned.... 

Monday, 13 June 2022

Victron VE.Direct to SignalK

Hi everyone,

Another technical post today, following on from our recent Lifeline/Victron Lithium Power Upgrade post.  Our plan was to feed selected data from the Victron gear into our SignalK system.  We've started with the 712smart battery monitor which provides the most useful summary data.  The overall goal was to integrate live battery state with other boat data on our Macs, iPads and iPhones, record the data in our SignalK system and graph historic data.

WilhelmSK app with battery data in blue oval

All of the Victron gear we purchased for the Lithium upgrade is 'smart', meaning each provides a Bluetooth connection for setup and monitoring.  This is great but historical data is limited.  In contrast our SignalK system accepts live data and stores it in a database which we can interrogate and graph at any time.  Apart from occasional maintenance outages every second of all our NMEA 2000 data is already stored in the database and can be graphed.  The record goes back to September 2020.  We're now recording the 712smart's data in the same database.

In addition to Bluetooth each of our Victron gear has a VE.Direct port.  Victron provides useful information on this interface here.  Here's one helpful picture from the VE.Direct Protocol document...

VE.Direct Socket Pinout

The VE.Direct physical plug is a JST PH 2mm 4-pin.  The electrical interface is 3.3V RS232 serial with pins 1 o 4 being ground (black), TxD (green), TxD (white) and power (red).  The interface runs at 19200 baud.  Victron sells VE.Direct to VE.Direct cables of various lengths and also a VE.Direct to USB Interface cable.  Very importantly the latter is isolated so differential ground voltages don't matter.  Local grounds at each charger and at the house distribution panel could differ due to the large currents the chargers inject.  We sourced Victron cables at Island Water World and Turbulence here in Grenada.

JST PH 2mm 4-pin plug (not VE.Direct wiring pinout!)

Our 712smart is mounted on the rear face of the pedestal in the saloon.  The cable run from there to the BeagleBone Black SignalK computer in the navstation is about 8m.  The VE.Direct to USB Interface cable is only about 1.5m so we used a 10m VE.Direct to VE.Direct cable for most of the run.  With no known local source of JST sockets we instead decided to cut the two cables and solder the wires.  Should be simple.

After cutting the VE.Direct to VE.Direct cable then exposing and stripping the four wires I plugged the other end into the 712smart.  The wires were black, green, white and red as expected.  I measured the voltage from red to black and got -3.3V.  Not what I expected.  I then disconnected from the 712smart and buzzed out the cable.  Pins 1 to 4 were connected to the cable wires in reverse order!  Not impressed!  Only TxD (white) and RxD (green) should be reversed.

With the wire reversal understood I could then reconnect to the 712smart and look for output data on the white and green wires.  It was on the green (measured with respect to the red!).  I then knew which wires to connect to the 'matching' exposed and stripped wires on the VE.Direct to USB Interface cable.  I only needed ground and the TxD wires from the 712smart.  It's really not nice soldering red to black, but that's what was required.  And green went to green, when normally you'd go white to green.

Before heat shrinking the connections and the cable overall I connected the 712smart and plugged the USB plug into our Macbook.  Displaying serial data on MacOS is tricky since it really likes 9600 baud.  The following command worked for me...

stty -f /dev/ttyUSB0 19200 | cat /dev/ttyUSB0

Sadly I failed to take a screenshot of the data.  There is a burst of text lines each second.  Each line contains a paramater name and value.  

With the cable assembly now tidied up and known good I connected the USB plug into the SignalK computer.  I then listed /dev and found a new ttyUSB device.  With the SignalK Server running I could also check the identity of serial devices by listing /dev/by-id.

SignalK Server's helpful Serial Port aliases

Earlier I had installed the SignalK Server vedirect-signalk plugin.  With it installed and data available the next step was plugin configuration.  Here's ours..

SignalK Server vedirect-signalk plugin configuration

With the configuration saved I checked connection activity on the SignalK Server's home page.  Data was flowing...

vedirect-signalk interface up and running

And on the Data Monitor page I could see the data...

vedirect-signalk data set

So we now had 712smart VE.Direct data flowing into the SignalK Server and onward into the InfluxDB database.  The final steps were to create a new Grafana page to display the data, and to modify other Grafana pages and the WilhelmSK app's pages to show key new data.  I'm not going to try to describe how to make Grafana pages - consult youtube!

The new Grafana "Electrical" page below shows our house battery bank state on the dials in the middle, and historical graphs of each parameter for a selectable time period.  The engine battery voltage is also shown on the voltage graph.  Here we're showing about 30 hours of data...

Grafana graph page of Victron data

The graphs above start with the battery bank 50Ah below full.  We had just turned on the mains charger which was injecting 30A in Bulk charge mode.  The solar charger was adding a little.  Voltage gradually increased then sharply increased - a characteristic of LiFePo4 batteries.  The chargers then backed off the current in Absorb then Float modes.  For the rest of the day the mains and solar chargers kept the battery full.

In the evening the mains charger was turned off and overnight the battery gradually lost charge, mainly running the fridge.  This consumed about 25Ah.  The following morning the solar charger filled the battery bank by midday, under a very cloudy and rainy sky.

Our solar panels are two parallel SunForce 130W panels.  They guarantee 80% power after 20 years and ours are 10 years old, so should yield 234W.  A few days ago when the batteries were fairly low and we had sunlight I measured 220W which I'm happy with.

Here are our new batteries' charge and discharge curves from the Lifeline manual...

Charge Curve (note voltage step)

Discharge Curves

It's great to be recording battery data only a few days after installation.  We're already learning more about our power consumption as well as the new batteries and chargers.

Trust all's well where you are!