The Great Wander

Let’s talk a little about managing power on a sailboat.

When we lived in our house(s), I walked in, turned on a light and left it on.  I would stand in front of the fridge with the doors open wondering what in the world I wanted  (even though I wasn’t that hungry).  Run the AC with windows open…ok maybe not that far, but  you get the idea.  In your home, you don’t really have to worry about power too much.

On the boat, power is much more of an issue.  All of our house systems (e.g., fridges, lights, navigation equipment, fans, etc.) run off of two 12 volt batteries.  These batteries are much bigger than the batteries in your car!  They have a total of 510 amp hours, which means that for 1 hour, we could draw 510 amps.  That’s the simple way of looking at it.  It’s not quite that straight forward, but close enough.

12 volt batteries, when they are fully charged, are actually at about 13 to 14 volts.  Unless you are using lithium batteries, you can’t let the batteries drop much below about 11.9 volts.  It’s important then that you have a solid method of charging.  We have three methods of charging.  First is solar power.  Second is a generator.  And third is running the engines.

Our ideal method of battery charging is solar.  The sun hits our solar panels, then charges the batteries.  If there isn’t enough sun to charge the batteries, we will run the engines or the generator.  When you are at the dock, it doesn’t matter.  Our battery charger is always plugged into the shore power.  At anchor, however, we have to watch the power usage much more, making adjustments as needed.

 Making adjustments means a couple of things.  First, determining if we  need to get the batteries charged, then either starting the engines or getting out the generator then  getting the battery charger going. If the batteries aren’t that low, but I’m concerned about power consumption, I look at what’s running and what needs to be running. Then I turn those things off that we don’t need.  On a lot of boats, people turn off fridges and freezers at night to conserve power.  We don’t do that. What I will do, even during the day, is use my portable power bank (that is also solar charged) and try to run things off of that.  There’s no reason my phone has to be charging from the house battery banks, when it charges from a portable bank, same with the router.

There are other little things that we do too.  Lights aren’t on if they aren’t needed.  The fridge door isn’t open unless it’s absolutely necessary.  While we love running our fans, we  only run the ones that we need.  Nothing gets left on if it’s not necessary.

When we are underway, we do have all of our navigation instruments running, except the radar.  For the little jaunts we’ve done, we don’t need the radar, so I don’t turn it on so I can conserve power.  Although our radar doesn’t draw that much power anyway.  Plus if it’s sunny…well, everything can be left on!