Friday, March 14, 2014

Oh It Feels So Good to Be All Charged Up Again!

Leaving Jolly Harbor was difficult since we had such a great time there, and more importantly, got used to staying on a dock just a short walk from a good restaurant, pool, grocery store, etc. One thing we won’t miss is the Tuesday Night Karaoke Competition where very drunk tourists sing very off-key and very loudly.

We left Jolly Harbor on March 14th and anchored just offshore so we could clean the boat bottom after the long stay in the harbor. That would have been fine except I’d forgot that I’d already used the SCUBA tank to clean the prop and it was only ½ full of air.  I decided to focus on the deeper and dirtier parts of the hull and prop, doing the easier stuff with our snorkeling gear.  I really enjoy working under the boat, it’s the one place it’s quiet and peaceful, as long as the barracuda’s keep their distance.

After flying 20,000 miles, a medical scare, and having guests on board for a week, Walter takes some much needed sleep on the passage to St. Barths.

We got an early start the next morning for a great sail over to St. Barths. We had thought of trying to make it all the way to Sint Maarten but it would have meant an all-night sail, and given that we hadn’t sailed in more than a month, we decided to ease into it.  We enjoyed wonderful beam winds of 15 - 20 knots and 3 to 4 ft. waves. As we approached Gustavia we were amazed at the sheer number of boats anchored, then remembered that last time we were there it was during the off season.

Large cruise ships and mega yachts anchored off St. Barths made for some interesting sailing between the behemoths.
We continued sailing around the corner, dodging mega yachts the whole way, to the beautiful harbor of Anse Colombier.  It was also gunnel to gunnel with boats, but we found a place toward the outside to drop our anchor for the night.  The weather had been perfect and we enjoyed just sitting in the cockpit and watching the sunset with a drink in hand.

The next morning we calculated our departure to arrive at Sint Maarten in time for the 11:30 am bridge opening, but unfortunately we were sailing too fast and had to keep reducing sail to slow down. We still got there early and spent an hour just sailing back and forth through all the boats anchored near the bridge.  At 11:30 am the bridge opened and we all hustled to get through the narrow opening to the inner harbor, called Simpson Bay Lagoon, before the recalcitrant bridge tender dropped the bridge back down.  We had decided to stay on the Dutch side since we were having a lot of work done to the boat, and the Dutch side is where all the marine stores, vendors, etc. are located.

The purpose of our visit was to replace the house battery bank, add two additional batteries, and install solar panels on the boat (since our much despised generator had recently died [or was it murdered?]). David, the electrician, came over and we took off in his workboat to pick up the 700 lbs. of batteries from Budget Marine, which is located right on the lagoon. Great plan, bad timing. I had called ahead to make sure the batteries would be ready, but got there to learn the elevator to the 3rd floor of their warehouse had just broke, but would hopefully be fixed later that day. David gave me a sly grin and said “That means later in the week if we’re lucky.” Sure enough, David was right.

So after all this careful planning and coordination, here I was to pick up my batteries and they were snug as a bug in a rug on the third floor. Not wanting to carry the 130 lb. apiece batteries down three narrow flights of wooden stairs, we acquiesced to fate and the elevator repair man.

We spend the next week doing various boat projects, with me spending the majority of my time learning why I could never be an electrical or structural engineer.  Since the genset had died, we had made the decision to add more solar panels to the boat. That’s easy if you are a catamaran with acres of space, but difficult on a sailboat.

My job was to figure how out the 1) boat’s power consumption, 2) the amount of electricity needed to replace that consumption, and 3) the size of the battery bank to store the electricity produced. In addition, I had to determine the number of solar panels needed, the size and weight of those cells, and what type of structure was needed to support all that weight and windage.

I remembered P=I*E from my hame radio class, but since our boat is a mix of 12 and 24 volt it made a somewhat simple project very complicated.  I built a spreadsheet and reviewed the data sheets of all our electrical devices to determine the number of amps they drew. I also tried to use the amp meter to determine usage, but found there was no “normal” on the boat. Somedays it’s sunny all day and the solar produces lots of power, and somedays its cloudy. Some days we run the stereo all day (it’s got a big power amp) and somedays we don’t. A pump whose data sheet shows it draws 8 amps draws only 2 when I read it with my amp meter. Go figure.

My best guess was that we used about 70 to 120 amp/hrs at 24 v, (140 - 240 amp/hrs at 12 v) on average in a 24-hour period. This means two things, we need a battery bank large enough to use only 45% of its capacity on any given day (it’s detrimental to draw a battery bank below 50% of its capacity), and we needed enough solar cells to generate at least 140 amp hours over the 5 hour solar day (hours of the day when the sun is high enough to produce good solar power). Everyone I talked to said “error on the high side of everything,” so I added in a fudge factor to the calculations.  On the battery bank side we added two additional batteries (two 12 v batteries wired in series with our current bank) to give a total of 550 amp hours of storage. That should give us more than enough storage to never run the batteries below a 50% discharge rate.
Island Water World on Simpson Bay Lagoon had the exact-sized solar panels we needed in stock.
 On the supply side, we already had two Kyocera 135-watt panels wired in series for the 24 v system. These were mounted on top of the bimini. We decided to add four more Kyocera 140 panels, with each pair-of-two wired in series. We had wanted to go with two 215 watt panels (which were available locally, but it turns out they do not produce enough voltage for a 24 v battery bank). The new panels will go through their own Blue Sky MPPT controller (similar to the the existing two panels), but the two controllers will be networked so we can monitor amperage from each bank. I have to admit this is all above my head, but I think we’ll be OK on the supply side with approximately 160 amp hours produced each day.

I will spare you all the phone calls, emails, in-person visits I made with the so-called “experts,” none of whom seemed to agree on anything consistent for me. I also had to decide whether to buy the panels locally, with limited selection and higher prices, versus having them shipped from the States. I worked with Eco Direct out of California and they were great at helping me make decisions, but by the time I’d ship their very reasonably priced panels to Sint Maarten the cost was exorbitant. I ended up buying a Blue Sky control and iPn monitor from them since a friend was flying down the next week from the States and could fit it in her suitcase.

On the home front, Meryl found a local German lady would could repair the rotted zippers in our dodger and install new vinyl windows so we could actually see out.  Turned our her husband was a shipwright, so I hired him to help me design a rack that would fit over our davits to hold the 130 lbs. of solar cells. We had two choices for mounting the roughly 4 x 8 ft of panels: 1) built a very expensive stainless steel tower that would rise up about seven feet and contribute a lot of weight in the wrong places, high up in the air and aft on the boat, or 2) build a simpler rack that would fit on top of the davits. We selected the second choice, realizing that we’re pushing the limits of our davits. We will need to make sure we take the engine off the dingy during passages to reduce the overall weight on the davits, but we think it will work. How it will look is anyone’s guess, I hate sailboats that look like spaceships or junkyards, but we do need electricity.

David preparing to remove the old batteries. The Lifeline batteries we used were an oddball size to fit into a very specific space under the saloon seat.
About a week later we got the call from Budget Marine that their lift was fixed and our batteries were now on the ground floor. David the electrician (who has a bad back from Vietnam) and I went over and carefully loaded them into his workboat, all 700 lbs. of them, and slowly motored back to Flying Cloud.  Luckily we could use our outboard motor lift to get them up on the deck, and then carefully walked them down the crowded side decks stepping over cleats, fitting, and lines.  Getting them down the companionway steps was a challenge for two guys in their mid 60’s, but it worked. We were both sweating like pigs the whole time.

Oh, I forgot, we had to reverse the whole process and remove the dead batteries from the boat, walk them down the side decks, lower them to the dingy, and take them back to Budget Marine for proper disposal.  No need to go to the gym today.

Once David got everything wired together (running the new battery cable was also quite the project) we saw 28.6 on the voltmeter, a number we haven’t seen for over a year. With the extra capacity we now never come close to running the batteries down like before. Eureka. We still have to run the engine two hours a day to recharge, but having the extra capacity has been wonderful. Now we just have to get the new solar panels mounted and connected and see how we do on the supply side.

Another spectacular sunset on Simpson Bay Lagoon, Sint Maarten.


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