The Doldrums

                                                                        The Doldrums

Wed Jan 31st, 2024- It's been a quiet couple of days hanging out on the boat without any WIFI.  I've been watching some of my old favorites on DVD when I'm not writing, or plugging away on the boat.  I managed to finish the installation of the SSB, now I've just got to read the rest of the instructions on how to actually use it!  When we're without WIFI the SSB will still allow us to keep up to date on the weather, at the very least.  Had Starlink not been so expensive ,we would have been much better going with it.  Every other boat down here is using Starlink without fail, the Bahamas is considered close to shore so they don't even need to switch to priority in order to get service.  Oh well, we'll have to live with Island Wifi for the duration of our trip and make the best of our disconnection.

  The water maker still isn't working, I'd like to get it sorted out before heading south again, but I'll need to get connected to some reliable internet first before I make the call.  I don't want to drop the call in the middle of a  tutorial on how to fix it.

  Now for some technical talk about batteries and charging for those interested.  My biggest mistake re-fitting Island Eclipse was in leaving the A/C refrigeration compressor.  Most boats use D/C compressors that utilize power directly from the battery, on demand.

When the fridge thermostat reaches it's high temperature threshold it triggers the compressor to start cycling, it only consumes power when the compressor is running.  The trouble with running an A/C fridge through an invertor is the continual power consumption of the inverter as it idles in wait for the compressor cycles.  

Between the inverter and the battery monitors there is a continual 6-amp draw.  Which means we're consuming an additional 120 amps a day waiting for the compressor.  That is a  huge amount of wasted power, and the primary reason we have a power deficit at the end of every day.  

For those new to cruising and overwhelmed by the talk of amps, amp hours, and volts I'll try and put it in a nut shell.  Batteries are rated in volts and amp hours.  Volts indicate the type of power being supplied and amp hours are the amount of power stored in the batteries.  If a battery has 225 amp/hours of stored power that means you can run a 1 amp light for 225 hours or a 2 amp light for 112.5 hours.  A house bank is rated in amp/hours based on the number of batteries in the bank and their combined total.  

  Solar panels are rated in watts, amps, and volts similar to the ratings of a battery.  Solar panels produce a D/C current that is used to replenish the batteries throughout the day.  A solar panel array should be able to produce an equivalent of 10% of the battery bank's power, per day.  In the case of Island Eclipse we have 12 x 6 volt batteries in series-parallels to produce 12v and a storage capacity of 1175amp/hrs.  Meaning I can run a 1 amp light bulb for 1175 hours.

  In a perfect world a battery bank as big as we have should be more than enough to get us by, however different batteries have different charging, depletion and re-charging characteristics.  Our lead acid golf cart batteries don't like to slip below 50% of their capacity or their life expectancy is dramatically shortened and charging times extended.  Newer Lithium batteries accept a much greater depletion of 85-90% as well as an increased acceptance of power when charging.  Although the characteristics of a Lithium battery sound great they are considerably more expensive and without fail-safes and by fail- safe I mean reserve emergency power.  

We've all had the batteries on a standard flashlight or toy go dead.  they slowly dim over time, or the motion of the toy slows as the stored energy depletes.  With a lithium battery there is no dimming, it simply stays fully illuminated until it doesn't.  A small control computer in each battery controls output and discharge threshold, so once it reaches the bottom floor that's it.  There's no squeezing out those last amps to keep a light lit, a solenoid open or crank an engine with the decompression lever up.  Once they're done, they're done.

  As a boater I find that a little scary, and so do others.  That's why a lot of boats are running a highbred system of lead acid, or AGM batteries for starting and Lithium for the house bank.  I imagine the lead acid batteries connected to the Lithium through some sort of controller that uses the lithium to charge the start batteries. 

  So, with 575amp/hrs of stored power and 1100 watts in solar potential we still find ourselves looking at a deficit at the end of every day.  As the days get longer the deficit shrinks but we still need to run the generator once or twice a week depending on cloud cover and prevailing winds.  With 400 watts of solar on the hard top and 700 watts on the arch a north wind is best, it keeps all of the panels out of the shadows of the boom and the mast.  The only rub is the prevailing winds in Bahamas are east so we very rarely get full production out of all the panels at the same time.  At best we're getting 350-400 watts of exposure for most of the day, and with 120 amps out the window before we even turn on a light, it's been a challenge for sure, and a learning experience worth sharing.

  It's around 830pm and the wind has turned from a whistle through the rigging to a howl, and the terrible creaking stretch of the anchor bridal echoes through the boat.  The short stiff chop laps at the hull, as the wind whips past the mast.  The salon table vibrates, as the gusts reverberate down the mast rattling the utensils on my dinner plate.  The boat continues to sail at anchor, one moment the wind is to port, the next it's to starboard. The sudden changes in motion make it feel like you're cornering in a race car when in fact you're just swinging around a hook in the sand.  I'd be more concerned about the conditions if I could do anything about them, but I can't.  I dropped some 90 or so feet of chain and we've held fast for the last five days, that will have to be reassurance enough to let me sleep. 

  The internet was back up nd running today, so I was able to have a video chat with Deb, it was so nice to see her smiling face even if she is thousands of miles away.  We finally got a chance to get caught up on each others lives and days events; while also planning her upcoming visit.  I eagerly await both Deb and Henry's arrival so we can get back down to the business of exploring and adventuring!  And with that, I will bid you all adieu for the evening, I'm off to walk the deck and check the anchor and the dinghy before calling it a night.

.  Thanks for reading.