Please visit our home site at

Anke and I live aboard WAYWARD, and wrote about it's design and construction at

Access to the net comes and goes, so I'll be writing in fits and spurts.Please feel free to browse the archives, leave comments where you will and write... I'll respond as I can.

Fair winds!

Dave and Anke
triloboats swirly gmail daughter com

Monday, February 27, 2012

Electricity in a NutShell

Nikola Tesla, Boat Electrician Extraordinaire

There are few areas, in boating, that attract more gew-gaws, gizmos and gimcrackery than the electrical system.

Time was, nobody had one. Oil lamps for cabin, anchor and running lights. Lead lines for sounding. Paper charts and a handful of tools for navigation. A fiddle, squeeze-box and lungs for music. Hailed passing ships with a bellows voice. Sailed with eyes and ears open by night.

We sailed our first ten years this way, and loved the simplicity. But lamp oil's getting rare and expensive. It's messy and doesn't burn quite clean... even a well trimmed wick irritates, these days; we became slightly sensitized, over the years. So electricity it is.

Now, I'm no technophobe. But I notice that I've stepped onto a slippery slope!

Here's a simple, modern Wish List:

Radar, GPS, Computer with Nav Software, Auto Pilot, Windlass
VHF (Base Station w/ Antenna and Coax Cable)
Depth Sounder, Knot Meter, Anemometer
Fridge/Freezer, Freshwater Pressure System
Running, Anchor, Spreader, Spot, Cabin Lights
Bilge Pumps, Sniffers, Blowers, Fans, Engine Starter and Wiring
Music System (Player, Speakers)
Solar Panels (1KW?), Controller, Battery Bank, Pulse Desulphator
Wiring, Switches, Fuses, Distribution Panel
120V Shore Power Parallel system, Inverter
Dry Cell Battery Charger, HeadLamps, FlashLights

That ain't asking much... no electric furling, winches, ham radio, single-sideband, TV... and the computer doubles as a DVD player (my aren't we the thrifty ones!).

And that only comes to... hmm... carry the two... decimal point here... YOW!!!

Here's the problem. If you, like us, have a shoe-string operation, a wish list like this one is going to come out near the price of whole rest of the boat. The less expensive the boat, the worse the relative bite of the electrical system.

Okay. New approach. In this one, we try to think like a Jeep, rather than a Cadillac.

Goals are few components, reduced complexity, low draw.

New, leaner, meaner Final List:

Radar, GPS (Hand-held), Computer (12V) with Nav Software, Auto Pilot, Windlass
VHF (Handheld)
Depth Sounder (Leadline), Knot Meter, Anemometer
Fridge/Freezer, Freshwater Pressure System
Running, Anchor, Spreader, Spot, Cabin Lights
Bilge Pumps (Bucket and Sponge), Sniffers, Blowers, Fans, Engine Starter and Wiring
Music System (iPod and iHome)
Solar Panel (130W), Controller, Battery Bank, Pulse Desulfator
Wiring, Switches, Fuses, Distribution Panel
120V Shore Power Parallel system, Inverter 
Dry Cell Battery Charger, HeadLamps, FlashLights

Wiring et al is held to a minimum by using rechargeable (NiMH) drycells, and charger for hand-helds, anchor and stern lights. An outlet circuit powers computer, charger and music. Few circuits (cabin lights, nav lights and outlets) allow bargain distribution panel. Battery's a Group 27 lead-acid (car) battery, rated 107Ah.

[NOTE: Check around harbor dumpsters for abandoned batteries. Can trade them in for discount on new one, and/or try reconditioning with a Pulse Desulfator. These pulse a charge through the plates, knocking sulphates free, thereby upping battery capacity. They are believed to extend battery life, and can moderately restore lost performance. Cheap, relative to batteries, so pay for themselves over time.]

I can't stand cigarette lighter plugs. Bulky and designed to break the connection. We're looking into PowerPole Connectors as an alternate.

For an anchor light, we use a little Brunton LED tent lantern. It's waterproof, and a single charge of its 4xAA batteries lasts about a week of nights. We've got a bigger, 30 LED lantern that we use if anchored near town (city lights). It doubles as an area light if we have to work outside at night. Inside, the main light is a 'natural tone' florescent, supplemented by candles.

[NOTE: Check with local churches... there's almost always a little storage room full of half-burnt candles they're happy to dispose of!]

The computer is a luxury... it pays its way by allowing me to write and finalize designs on board. It's an ASUS 901 EEE... 12V and solid state drive means low power consumption.

Our Solar Panel (Kyocera KC130TM), is the biggest that will fit on deck. These employ a technology that's more output on a smaller footprint, and is more efficient in cloudy or low light conditions. We oversized it (spendier option) to reduce having to orient for optimal performance (sometimes, in winter), and to cover occasional, creative fits on the computer.

The Solar Panel is by far and away the most expensive component. One option is to go bargain basement (many 2nd hand deals). We've gone, instead, for higher performance, small footprint and long, guaranteed life to prorate cash investment, and reap performance dividend.

This all still costs a galling 10% of SLACKTIDE's total (including the electrical system and copper plate).

The VHF base station is the one thing I hanker after. We get a good five miles, line of sight, with the hand-held, but Alaska eats that up pretty quick. I've spent enough time in EMS circles to appreciate long distance communication. We seem to have a general surplus of power, though we'll look for a radio with low stand-by power draw.

One odd-ball item we're looking into is an ionizer. These help clear the air of particles (dust and woodstove). They make a li'l, 12V guy for cars that should handle our space. [See SHEMAYA's comment, following post].


Also on the cost list are tools and materials. I won't detail it, but it's a fairly spendy kit when all the dust settles. We like a butane soldering torch, though are considering a 12V iron. Don't forget a multi-tester!

A good reference book is a fine idea. We found the The 12-Volt Bible for Boats by Miner K. Brotherton to be very easy to understand... something to be valued over brevity, at least to get going!

The electrical system is one of the main causes of fire on board. Bone up on safety standards, and follow 'em for trouble free function. Don't forget type ABC (C=electric) Fire Extinguishers.

The best systems, once installed, go forever after unnoticed.

PS. So far, we've only ocassionally run low on power (50% of battery charge) in the dark o' winter. It's a portent that I'm spending too much time on the computer and need to take a break. Our 7W florescent cabin light and LEDs are just sipping power, so the next daylight hours will start catching us back up. Most of the time, there's power to spare.

This post also appears at


  1. Hi Dave,

    What a great list, and such a thorough way of trimming down to necessities. Which model of Kyocera 140 W was the one that you settled on? What a process that is, to sift through the capabilities of everything that's out there lately!

    On the car ionizer, have you gotten to try one? Depending on what works for you, they can be good or not so good -- not necessarily individually, but as a category of air treatment. Well, probably individually it does make a difference... but the big issue is that while they are doing the good thing of producing negative ions, my understanding is that there is always a certain amount of production of positive ions. Positive ions are good for clearing a space if nobody is in it -- say as a short-term strategy after a fire. But they are quite hard on people's lungs (as well as, interestingly, wiring insulation). What I finally came across somewhere is that the same way they grab tiny particles from the air, they grab tiny particles from lung tissue. Ouch! Personally, I've experienced significant lung irritation from equipment designed as negative ion generators.

    On the bright side, negative ions are generated specifically by wind moving across water -- and you have such a good supply of that handy! Maybe some specific rounds of ventilation would achieve the same goal as the ionizer? And cheaper!

    -- Shemaya

    1. Hi Shemaya,

      Whoa! I had no clue that there was ANY downside to ionizers... thanks for clueing us in!

      We haven't used one, but have been looking at one we saw in GAIAM... a little fella who sticks into a cigarette socket.

      Interesting note about natural negative ions... I'd always thought we've had less problems with dust than I'd expect. That could well be the reason. AND I love the price!

      Got change for a penny?

    2. Hmm...

      Looking it up, I see we have a Kyocera KC130TM.


  2. I love my little smartphone, hardly any power draw, GPS and compass built in, and $22 nav software (navionics)... It can also send internet to my computer wirelessly so doubles as a modem, and also an Ipod and FM radio. Simplicity itself and cheap if you can find a gadet freak to get an older model from. I can also read all em kindle books on it for free or nearly free.

    1. Hi Ben,

      Coverage can be a problem, up here, but it's here and there.

      We got a KINDLE (guess I should'a added that to the list). It's been great for carrying books I love to read but can't afford the weight (Stevenson, London, Doyle, for example... all free!).

      But another big advantage is that they're Whispernet access (available with all cell coverage) is covered by the initial purchase price (no monthly payments). They have a primitive web browser, but it allows us to check mail (sending is possible, but painful).

      Must say I'm looking forward to decent connectivity!


    2. I am really enjoying your writings and ideas.

      Someday I will get a proper kindle, better battery life and easier reading. With my Smartphone I usually just disable the phone part when I am away (airplane mode), saves batteries and annoyance, but I still have the handheld chartplotter, music and books, camera and video... Technology! I think with the right setup (bluetooth keyboard?) a smartphone could almost replace a computer, Ideal for real small boats

      I remember having an old pocketmail device and getting emails through it from public phone boxes, now that was painful.

      I guess on a tight budget the whispernet makes a lot of sense.



    3. Yeah, they had me at TIGHT BUDGET.

      Last I checked SMARTPHONE ISP basic package was running $90+/month, aka $1200+/year. Almost 20% of our yearly average.

      We used to have POCKETMAIL, too, which I still think was a brilliant, transitional technology. I'm hoping the same for keyboards... maybe SIRI and EVI are the beginning of the end.

      And I SPIT on QWERTY layout! I still haven't taken the time to learn DVORAK, but I resent every reach for the E.

  3. I've been cherry picking through your posts relying on the title to pique my interest. This one did. Re batteries, get to know the cable guy they use sealed gel cell 12v batteries to boost the cable signal and then throw them away about once a year, they're still good batteries' I have five of them. Good ballast too they weigh about 70 lbs apiece.

    1. Hi Kevin,

      Great tip!

      Do you happen to know how many nominal amp-hours these batteries have?

      Dave Z

  4. It sure would be nice to see an expansive upgrade to this article: details of shore power, battery locations (and types), integrating solar and wind, details of wiring in a minimalist design… oh, there are so many questions!

    1. Hi,

      I've got an article in the works... one of the things that has changed since this post is that USB charged, 5VDC systems now have components for most of the items a small (jeepy) vessel needs. They're mostly cheaper and a lot easier to power.

      We've eliminated most wiring by going to rechargable batteries, either AAA or device-specific.

      Haven't tried wind generation, but solar through inexpensive controllers seems to do great.

      More coming this winter.

      Dave Z