Hera Recommissioned in Grenada

Each year we make a number of upgrades to Hera and keep on top of any minor repairs in addition to the annual maintenance routine. I have found that only by doing this can you keep a boat in good condition and maintain its value.  This year i decided to document the process of recommissioning Hera after six months in the boat yard. Spoiler alert: its long and quite technical and will probably only appeal to about three people - you know who you are. 

The first week we go through the work that was done (or not done) over the summer, getting unfinished projects completed and overseeing the final work before launch. A number of tasks have been entirely neglected so we delay the launch by a day to get everything complete. After much negotiating over the invoice, we pay our bill on the basis of ‘no cash, no splash’ and tie up to the dock. The heat at this time of year is intense with day-time temperatures around 35 degrees and very high humidity so we work on commissioning Hera during the day, but spend the nights at our hotel as we acclimatise. 

Finally, it’s time to leave the dock and anchor in the bay. Our friends Chris and Heather are working on their boat in the yard and they spend the night on Hera the day before their launch. We have had two new turbo chargers fitted over the summer and one was smoking a little when it was run up on the hard so we motor out of the bay to test it. At low revs a little smoke comes from the exhaust, which we put down to some remaining oil in the cooler but when I put the engine under load, huge clouds of dense white smoke pour out of the exhaust and a sheen of oil forms on the water all around our boat. We tie up to a mooring buoy and report the problem to Stefan, the head engineer in the yard. Stefan thinks the new turbo has a fault in the seals so he rebuilds one working turbo from our two old ones and installs it. The old turbo runs without issue, confirming that the new unit is a dud. I contact the retailer in the uk who tells that in order to look at replacing it under warranty we have to send it back so that they can inspect it. We take a bus to the Fedex office in St George’s, the capital of Grenada, and send it back to England. 

While we wait for a response, I have become concerned about our house batteries. Last season we were planning to replace them and now this has become more urgent. Our batteries barely hold enough charge to keep our systems up overnight at anchor and when I test them, I calculate that they now have only about 15% of their useable capacity. So, while we wait for the turbo, we decide to bite the bullet and order new batteries. Initially I was planning to buy replacement AGM batteries, the same as the type that we have, only bigger, heavier and much more expensive. This is in some ways an easy decision as nothing else has to change; we just buy the new batteries, install them and off we go. However, AGM technology is now being superseded by Lithium Ion, the type of batteries that we have in our electric car, and there are many reasons to make this upgrade, but also some issues. In summary, Lithium batteries are smaller, lighter, they hold greater capacity, charge much faster and discharge faster allowing a wider range of uses. But they are notoriously more complicated to install and if not done properly can be a major fire hazard. 

We cost out the AGMs which we can buy in Grenada, and then research a supplier of Lithiums. Caroline makes a few calls and tracks down the supplier in Grenada who gives us a price for the batteries that he recommends, made by Epoch in the US. Not happy with the price he offers, Caroline gets the American head of sales at Epoch on the line and I talk to him about our requirement. For some reason he suggests making us a dealer, so we are offered wholesale pricing, which is about half the cost that the supplier in Grenada offers us. Having spent the past two years thinking about this upgrade and discussing it with my good friend Jan, I know that our charging systems will support these high-tech batteries so I run it past the electrician who looks at my diagram, thinks quietly for a few minutes and says ‘no problem’. He talks me through the install process and how he has the software to configure each of our charge regulators with his PC and I am convinced. We calculate that by ordering them from Atlanta, then shipping from Miami to Grenada on a freighter and paying for the installation, they will still cost us less than the old tech AGMs, so we make the decision and place the order. It will take two weeks for the batteries to arrive so we settle down and wait. 

Meanwhile the UK distributor of our turbos tests our faulty unit and declares it free of any faults. I contact the CEO of the distributor and tell him that by simply installing our old turbo without issue, it completely isolates the problem to their new unit and therefore whatever the technician thinks, the turbo is faulty. I also speak to the owner of the retailer and remind him of his obligations under the consumer right act and that our contract is with him, not the distributor. To his credit, he agrees with the distributor to provide us with a replacement unit as a gesture of goodwill, but they are all clearly expecting the problem to continue as they believe the fault is with our engine. While waiting for the replacement unit I do an online training course on turbos provided by the supplier and over the course of a few evenings in the cockpit I become a qualified platinum installer of turbos (with certificates) while Caroline watches Netflix. By the end of the course, I am equally convinced that it is unlikely that the fault is in the turbo seals, as the construction method makes this highly unlikely. 

While we wait for batteries and turbos we work through our list of overdue boat jobs during the day and go out to some of Grenada’s  beach restaurants in the evenings. Three weeks has passed since we launched Hera and we are becoming a little frustrated not being able to set sail, but we do get a lot of work done and Hera is looking sparkling after her summer polish of the topsides and the superstructure. As our batteries are so poor we have to run the generator frequently to recharge them and when we put the generator under load to run the water maker and charge the batteries, it overheats and shuts down. I check the cooling system and replace the impellor but the fault continues, always recurring after running for about 20 minutes. In discussion with my friend Chris from R5, we decide that the heat exchanger is probably at fault. The heat exchanger's function is to cool the engine without allowing the cooling but corrosive sea water into the working parts of the engine. It achieves this by pumping the hot coolant from the engine through a nest of narrow pipes which sit in a bath of cooler sea water. By pumping these fluids through the exchanger, the coolant temperature is reduced by transferring its heat into the sea water which gets ejected through the exhaust. The problem arises because these narrow pipes can get blocked, reducing the flow of coolant and causing the engine to overheat. I drain down the cooling system and remove the heat exchanger from the generator, a task that takes three hours and several litres of perspiration. I am pleased to see that the pipes are all congested so I soak the exchanger in a bath of Muriatic acid which clears the pipes beautifully, but also removes all the paint. I happen to have a can of Onan white paint in my spares box so I repaint it in the shade of some palm trees, then refit it with new hoses. This process takes an entire day but the generator now rumbles away happily under full load, so it’s well worth the effort. 

At last the replacement turbo arrives. I also decided to order new exhaust elbows, water elbows and exhaust hoses for both engines as the hot damp conditions around the exhaust are highly corrosive. The turbo is pristine out of the box but shiny aluminium and steel, not green like our engine and without a layer of paint it is much more prone to corrosion, so I spray paint the new shiny unit in enamel Volvo green, applying several coats in between downpours of rain. On one of the days at anchor we had the equivalent of one month’s rain in three hours which was astonishing to witness. Small streams became torrents of water washing tree trunks and debris into the sea, bursting water pipes and drains all over the island. When the rain eventually eases Stefan arrives and we set about installing all the various new parts. Stefan on the turbo and exhaust elbows and me on the water hoses and connectors. Caroline is the only person who actually reads the installation notes and points out that we have to manually oil the unit and rotate the turbines by hand so that they don’t seize before the oil pressure from the engine lubricates these delicate components. We sheepishly take the unit apart and follow her instructions. The moment comes for us to test the turbo, running the engine at very lows revs to allow the oil to circulate before putting it in gear and under load and pushing the revs up high. No smoke, no oil, just the sound of the turbine and compressor spinning smoothly and delivering that extra power. I am relieved and slightly surprised but Stefan was always confident in his diagnosis and just smiles. 

The next day our batteries arrive on a truck from the port and Meshach the electrician arrives with his assistant to start work. They begin by removing the old batteries and we construct the new battery box which I have made in advance from timber batons, painted with grey bilge paint. By the afternoon the new batteries are in and when we leave the dock for another night in the hotel, Meshach is configuring the regulators. The next day he is on the dock when we arrive and tells me that everything is done so we pay our bills and motor around to one of our favourite bays to test everything. Immediately I notice a problem. Because the batteries have now been on charge all night on the dock, they are now full and as soon as we run the engines at cruising revs, the alternators start charging in bulk mode, putting too much current into the batteries and they shut down to protect themselves from being overcharged. Each battery has a battery management system (BMS) integrated into it. This is a piece of electronics that protects and regulates the flow of current in and out of the battery. The charge regulators are supposed to detect the battery voltage and reduce the charge current as the batteries fill up, transitioning through the three modes of Bulk, Absorption and Float. Each battery has its own charge parameters and these are the configuration settings that Meshach has programmed into the regulators. I call him and he agrees to come to the boat in the morning to look at the issue. 

We motor into the anchorage and drop the anchor, but when I put the engine into reverse to dig us in, the boat starts to steer sharply to the right. We are anchored quite near a reef so its slightly alarming that we start motoring in a clockwise direction around our anchor. I quickly realise that the port engine is stuck in forward gear so I dive into the engine room and manually push the transmission lever into neutral. I can immediately see that the control cable has broken where it connects to the gear box just beneath the exhaust hose and I’m certain that it got damaged when Stefan was changing the hoses as they are a tight fit and pass only centimetres above the cables. Sitting at anchor that evening, we are a little despondent as we have now been in Grenada for over a month and we are still less than a mile from the boat yard, unable to run our engines and unable to go anywhere until the battery charging issue is resolved. As I remove the old cable the Morse bracket snaps in my hand but fortunately i have a spare, so i treat the corrosion, repaint the brackets in Volvo green and leave everything to dry. 

The next morning Meshach comes to the boat and checks all the configurations. They all appear to be correct and in accordance with the manual. The issue that concerns Meshach is that one of the batteries has a lower charge than the others. His theory is that one battery is asking for charge while the others are full, causing the BMS on the full batteries to shut down, which in turn switches off the charger, the current drops and the voltage shoots up to 32volts, well above the safe limit for the batteries. He plans to come back the following day with a charger to get all the batteries up to 100% charge and then test again. 

As soon as he leaves the boat, I go by RIB and taxi to the chandlery where I pick up two new 6 foot engine control cables. However, when I get back to the boat and remove the old cable, I discover that it is 2 metres long, not 6 feet, and the new cables won’t fit. However, I have two spare cables for my outboard motor and one of them just happens to be the right length and I set about fitting it. Hera has quite complicated engine controls. Because she is so wide in the beam there is a set of engine controls on both sides of the boat, and for these to be switchable, the control levers send electronic signal to a control box in each engine room which mechanically operates the push-pull cables using electrical actuators. This makes the cable job a little more complicated as I have to connect one end to the actuator and then recalibrate but it doesn’t take long and I refit it and it appears to work fine. 

The next morning I wake early to charge the batteries using the generator, leaving less for the electricians to do - only the generator won’t start. It normally produces an error code on the digital display but today nothing. I check all the battery connections and the start battery voltage and decide to try connecting it up to one of the new engine start batteries. Thankfully it starts immediately so I leave it charging the batteries while I take my RIB to the nearby boat yard where I buy a replacement start battery. Meshach turns up with his charger and charges each battery individually using AC power from the generator. It is during this process that he discovers that none of the batteries are reaching their absorption voltage and he calls the manufacturer to check the settings. Epoch give him the correct parameters (which differ from those in the manual) which he then uses to reconfigure all the regulators and everything works like a charm. 

Finally, everything seems to be in order. The change in the batteries is quite extraordinary. Caroline can now run her air fryer, hairdryer, toaster and coffee machine off the batteries and they barely notice. The alternators push in 120 amps in bulk mode when we are motoring, the AC charger 70 amps, and the solar panels 30 amps at peak sun hours. The key difference to the speed of charge is the batteries’ ability to take a bulk charge right up to 98% of charge, whereas on AGM batteries they switch to absorption at a much lower state, reducing the current and therefore prolonging the charge process significantly. 

I hope this lengthy description wasn’t too dull and boring. After a whole month in Grenada we are now sailing north through the islands. Happy Christmas.