Replacing the Starter Battery

Time seems to pass by in a quick sort of way these days. Here is a story from a little while ago…

Sunday, September 13 We had been procrastinating on putting in a new main engine starter battery largely because we were undecided about whether to replace it with the same size or a smaller one. On our last bay cruise, we noticed that the secondary alternator that charges the battery seemed to have inconsistent voltage drops. Hmmm”¦ was it the battery or the alternator causing the issue? We realized we couldn’t put off replacing the battery anymore. It was time to make a decision.

Our starter battery is a size 4D of type Acid Glass Mat (AGM) by Lifeline. Nordhavn is now using a smaller size 31 battery on 43’s. There were only two real pros for going with the same size battery. One, the installation would be a perfect fit. Eric would have to fabricate some pieces to make the smaller battery fit securely. Two, it is comforting to have a larger battery; you never know when you might need it. The pros of a lighter weight battery were certainly appealing. The 4D battery weighs 135 pounds, and smaller size 31 Lifeline battery weighs 69 pounds, which is a more manageable weight to work with for transporting and installing. And, the size 31 one costs $600 less.

We decided to go with the size 31 battery. Last weekend, Eric went to the store and picked it up. Then he got to work. Our lazarette is jam packed with assorted stuff, so clearing everything out of the way was a project in and of itself. We had installed a shelf over the batteries, which serves two purposes. One, it helps protect the batteries and two, it provides extra storage room. Getting the shelf off required unscrewing a bunch of screws, and it was a pain. The batteries are on the floor of the lazarette behind the rudder post and steering gear. Each battery is recessed into the floor by about 2 inches. Also there is a bracket that goes over the each battery that further keeps them from moving around. The boat could actually roll over and the batteries would be in place. There is not much vertical space, so it is difficult to get enough leverage to lift the battery out. Eric was able to tip the battery and get a bar under the battery which allowed him to shift it out of its recessed space. Then he could slide it over to the laz hatch. And, despite Christi’s big hulking muscles, she wasn’t much help to get the battery out.

To finish the project Eric constructed pieces made to make the battery fit snuggly. Also the battery posts were in a different spot, but thankfully the wires were long enough. But he did have to change the position of the bracket mounting points to make the top part fit over the new battery.

Before he put the shelf back in and repacked the lazarette, he started the engine with the new battery to make sure it was working. As he turned on everything, he noticed the stabilizers were working. What? The stabilizers have been dead for weeks! How come they are suddenly magically working? Today we found out something new about our boat: the active fin stabilizers are wired to the starter battery and secondary alternator, not the house bank of batteries. We can’t even begin to tell you how thrilled we are to know the stabilizers are working fine and do not need to be repaired.

Once the lazarette was cleaned up and the battery project officially complete, Eric went through Kosmos’ normal weekly exercise routine. He runs the engine, wing engine, bow thrusters, water maker, and everything else that needs to be regularly exercised. After running the engine for a while, it was clear that our secondary alternator is not working. He also changed the carbon filter on the water makers’ fresh water flush system and noticed the filter seal has a small leak. He turned the value for it off. That will be a project for another day. But, being that we were still elated over the stabilizers, these two issues didn’t bother us in the least. Neither was a big deal when compared to the stabilizers.

And, a blog question:

Q: What website(s) do you copy your history posts from?
A: Christi writes them all herself. She is a history buff and would read several history sources about each country. She would write a compilation of the things she thinks are most interesting. One of the beauties of having the blog behind real time was that we could gather info while in each country and then she could compile it after the fact, tailoring the histories to flow with the rest of the information in the posts.

More stories on the way…

4 thoughts on “Replacing the Starter Battery”

  1. Keep up these post Christi! This is exactly the kind of post I like. A good look into real cost & time involved in maintaining a Nordhavn.

    How the book coming?

  2. I see that you have redundant systems for stabilization. I am very curious if you actually use your paravane stabilizer at all? Or do you or can you ever use both? How dependable and effective is each system and if you were to buy a new 43 Nordhavn, would you equip it with both? Is the active fin system a fragile system needing constant repair? I am obviously ignorant on this subject, but very curious.

  3. Yes we do. Both systems together are great, and add comfort in bigger seas. The paravanes kick in right when the active fins start to let go on big rollers especially in following seas. Also with all the leverage the paravane poles are the best flopper stoppers at anchor you can get.

    The cons to the paravanes: The are a bit of pain to deploy and get back in. Christi cannot quite lift them. The drag is about 0.3 knots. And they can catch some pretty big pieces of kelp.

  4. I’d like to add to what Eric said. The stabilizers could be the hardest working component on the boat, so “fragile” may not be the right word since they do get beaten up pretty good. But yes, they have a lot of issues, and the issues are often very, very expensive to have repaired (Kosmos is now 9 years old and has 35,000 miles. At this point, we’ve probably spent about $1 per mile on the stabilizers). Would we get them again on a new boat knowing how many expensive headaches they cause? The answer is a resounding yes, because they make life at sea that much better.

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