When Batteries Go Bad

When it rains, it pours.  And when marine batteries go bad, they go bad pretty quick.

When we were in St. Maarten, Scott noticed that our battery voltage was low.  Like, really low.  For the record:  we have had two 12 volt 8D AGM batteries as our house bank.  They were reading 11.4 in after a night at anchor when they should have been reading in the high 12 range.  Much to his annoyance, I had been telling Scott each morning for days that our refrigerator didn't seem cold (I am ever fearful of wasting cheese!) and now, it seemed, we knew why.  Our batteries were dying a slow and steady death, and taking our cheese down with it.

Since we have a generator on board, this was by no means an urgent matter - or so we thought.  We continued on our normal course south, figuring this was nothing more than a minor annoyance, and that we'd replace our battery bank once in Grenada.  Our batteries, of course, had other ideas.

Each day our battery voltage dropped lower and lower, quicker and quicker.  We started going into energy conservation mode, turning off all systems at the breakers, and finally shutting the refrigerator off at night.  This attempt to tourniquet the outpouring of energy from our AGM's did next to nothing for the health of our batteries.  They continued on their downward slope, slowly draining a little more life, each and every day.  I was getting worried.  We ran our generator more to keep up with our energy needs.  While this charged our batteries for a spell, they just couldn't hold on to it.  Almost immediately after the generator stopped running, the voltage would drop.  I watched our Victron battery monitor religiously, hoping to see something positive.  It never came. Our fridge began to smell.  Food began to rot.  The mood on the boat drained along with the battery acid.

Then we couldn't start the engine, and this is when I began to cry.

I know we are a sailboat, I know that sails don't require power - but to me, an engine represents safety and when, after running our generator for thirty minutes, we still couldn't start our engine, I got very nervous.  We had a problem. (Note: our engine starter is tied to our house bank.  I know that this is not ideal, and it's not the way we would have set up this boat - but it's the way it was - we are learning there are LOTS of things the previous owner did that we would not have done).

After more generator running and some desperate pleas to the Universe to "please let our engine start one more time" our trusty old Perkins laboriously coughed to life.   And then I smelled sulfur which, unless you are near Old Faithful, is not a normal smell.  New smells on boats are bad and require investigation.  I did some quick Googling and after reading words like "over charged batteries" and "explosion", it was an easy decision to limp into a marina.  Which is exactly what we did.

Within an hour we located an electrician.  He went in the engine room and told us our batteries were "hot"...after which he smiled and shook his head "too hot".  They needed more ventilation.  We took note.  And he continued to poke around.  After a spirited "discussion" with Scott about what the problem might be and what, exactly, this "electrician" was doing (he never told us anything we didn't already know) - I decided to take a walk with Isla to give the men some room to work.  When I came back our 12V 8D AGM batteries had been replaced with 12V 4D wet cell batteries.  Not ideal, but they should get us through.  Thanks to the advice given to us on our Facebook Page, we changed the settings on our charger from 'AGM' to 'wet cell' and have added "check battery water" to our list of weekly chores.  We are also going to be much more cognizant of voltage and battery monitoring moving forward.

Neither of us feel entirely confident that our problem is solved - we're not entirely certain that we don't have some other electrical snafu that might have caused this in the first place.  But for the meantime, we have put a band-aide on the problem.  Hopefully, this band-aide sticks until we get to Grenada.  In the meantime, I'm going to eat me some cheese.