low-amp system for small sailboat

Hi, gang....total newbie here. i might not have some of the lingo completely down yet! I've been corresponding with the folks from Northern Arizona Wind and Sun and I finally noticed the link to this forum. So I'm going to quit squeezing free information out of them and come here with some questions.

The Project: July sailing race from San Francisco to Hawaii. Estimated amps burned per day is 50. That's low for a sailboat, but I have I have it that low becasue I'm using LED navigation lights, my GPS's are all battery-powered, I only run the radios for 15-20 minutes a day, I don't have radar, etc. The main draw on the electrical system will be 18 hours a day use of the autopilot @ 1.5 amps (27 amps out of those 50, right there!). I have two 90 amp-hour wet cell, deep cycle marine batteries.

I know that it's adviseable to keep the batteries from falling below 50% charge whenever possible. I will be carrying along a small gasoline powered DC generator that puts out 15 amps DC, and I can stomach running that for about 6 hours, maybe twice or God Forbid three times times during the trip. However, If I didn't have to run it AT ALL I'd be happier.

OK...the current plan is to install two kyocera 65 watt panels onto a Morningstar Dual Battery charger/regulator, which is hooked up to the two wet cells. I have a line on two used 30 watt panels that are small and can easily be moved around the boat to catch maximum sun.

SO....questions.

1. As I calculate things, it LOOKS like I'm in the ballpark in terms of generating power, here. Whatcha' all think?

2. With the Morningstar Unit in place, do I still need to install diodes to keep the batteries from discharging at night?

3. I'd LIKE to run the 30 amp panels into the Morningstar unit, too, but how do I do that? If I can only run the Kyocera panels into the Morningstar, and just alligator-clamp the 30 watt panels directly on the batteries, that works for me, too.
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Comments

  • BB.BB. Super Moderators, Administrators Posts: 29,218 admin
    Re: low-amp system for small sailboat

    One good Solar powered Sailboat thread here...

    Another sailboat thread...

    -Bill

    PS: You might want to look at a Honda eu1000i or eu2000i and a good battery charger--Both are pretty fuel efficient and will charge your batteries much faster than the 15 amp DC generator (what is the estimated fuel flow for that?).

    The first link is to somebody that actually raced the same race that you are probably entering--and his system, in the end, did not provide near enough solar only power for their boat (lots of cloudy weather at times).

    It is this race (Singlehanded Sailing Society)?
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • mike95490mike95490 Solar Expert Posts: 8,288 ✭✭✭✭✭
    Re: low-amp system for small sailboat

    You are WAY low on solar power. 130W - de-rate to 100W for 5 hours/day = 500Whours @ 14V (charge voltage) = 35AH per day, in PERFECT conditions (no shade lines on panels)
    [someone tell me if I screwed up my math]

    If it was I, I'd have 3x the panels you have (8 panels total)
    Price of panels, I'd get the generator and lug fuel. Do you need 2 generators for redundancy? How far is help if you need it?

    Do your radios run from dry cells ?

    The little Honda generator, driving a good 3 stage charger, a couple of hours in AM, & PM will be your best bet. You will still be decifict charging the batteries, and count on them being fried at the end of the race. Your existing solar panels will help very little.
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • icarusicarus Solar Expert Posts: 5,129 ✭✭✭✭
    Re: low-amp system for small sailboat

    I agree with Mike and Bill.

    I use a Honda eu1000 coupled to a xantrex tc 20. It burns ~1 litre per 4 hours. A Xantrex tx 40 would burn just a bit more.

    I run 220 watts of panel for ~ 20 amp/hrs/day used. (12vdc)

    Icarus
  • nigtomdawnigtomdaw Solar Expert Posts: 705 ✭✭
    Re: low-amp system for small sailboat

    Whilst I agree with everthing said.... your in a sail boat in the open sea, hopefully lots of wind pushing you along why dont you fit a small marine wind turbine. Whilst not recommending the infamous AirX ...there are other companies like Ampair and Rutland who produce sensibly rated machines which are popular with sailors. They work 24/7 track the wind unlike solar......maybe one case where wind wins over solar :blush:
  • nielniel Solar Expert Posts: 10,311 ✭✭✭✭
    Re: low-amp system for small sailboat

    bill,
    wow i almost forgot about that big race and believe it or not i still have much info on the updates as they were sent out.
    here's a link that i was sent with the pics of the boat (foolishmuse):
    http://community.webshots.com/album/553262832dhkqhJ
    i seem to recall some pics of the pvs that hung off the back of the boat, but i'm not seeing them at this point.
  • System2System2 Posts: 6,290 admin
    Re: low-amp system for small sailboat
    niel wrote: »
    bill,
    wow i almost forgot about that big race and believe it or not i still have much info on the updates as they were sent out.
    here's a link that i was sent with the pics of the boat (foolishmuse):
    http://community.webshots.com/album/553262832dhkqhJ
    i seem to recall some pics of the pvs that hung off the back of the boat, but i'm not seeing them at this point.

    Yes, that's Andy on Foolish Muse. Here's a pic of his solar array;

    FMuse.jpg
    ...you've got it right, this is the Singlehanded TransPac, put on by the Singlehanded Sailing Society of San Francisco Bay.

    http://www.sfbaysss.org

    Our forum

    http://www.sfbaysss.net

    Andy did have quite a bit of generating capacity on the back end of the boat, I don't remember him having issues with running out, and I know the people who delivered his boat back to Seattle. They bought a Honda generator for the trip back and never used it, but then there were two people on the boat so they probably hand-steered 12 hours a day or more.

    I know of a Moore 24 that did the race with about 200 amps of solar generating power and had no issues and he had a beefy autopilot. Another Moore 24 has done it with about 160 amps of generating ooomph. I know of a J-92 (30-footer) that did the race two two 40 watt panels and had to run his engine 3x for about 4 hours a pop.

    I'm gonna look up all your recommendations for generators, though. I'd sure like to see more than 15 amps coming out of the generator. Thats' what my current mini-gen-set pushes out, though.
  • System2System2 Posts: 6,290 admin
    Re: low-amp system for small sailboat
    BB. wrote: »
    One good Solar powered Sailboat thread here...

    Another sailboat thread...

    -Bill

    PS: You might want to look at a Honda eu1000i or eu2000i and a good battery charger--Both are pretty fuel efficient and will charge your batteries much faster than the 15 amp DC generator (what is the estimated fuel flow for that?).

    The first link is to somebody that actually raced the same race that you are probably entering--and his system, in the end, did not provide near enough solar only power for their boat (lots of cloudy weather at times).

    It is this race (Singlehanded Sailing Society)?

    Oh, that's funny..... I know born2sail very well, he and his girlfriend were the ones who doublehanded the boat back from Hawaii. It's good to know they were looking for information here, as well.

    That year (2006) was the slowest race on record..

    Honda eu1000i, huh? **going to hit google, now**
  • System2System2 Posts: 6,290 admin
    Re: low-amp system for small sailboat
    BB. wrote: »
    One good Solar powered Sailboat thread here...

    Another sailboat thread...

    -Bill

    PS: You might want to look at a Honda eu1000i or eu2000i and a good battery charger--Both are pretty fuel efficient and will charge your batteries much faster than the 15 amp DC generator (what is the estimated fuel flow for that?).

    The first link is to somebody that actually raced the same race that you are probably entering--and his system, in the end, did not provide near enough solar only power for their boat (lots of cloudy weather at times).

    It is this race (Singlehanded Sailing Society)?

    Oh, that's funny..... I know born2sail very well, he and his girlfriend were the ones who doublehanded the boat back from Hawaii. It's good to know they were looking for information here, as well.

    That year (2006) was the slowest race on record..

    Honda eu1000i, huh? It's DC output is only 8.3 amps, but I suppose it would drive a 20 amp portable charger, eh?
  • mike95490mike95490 Solar Expert Posts: 8,288 ✭✭✭✭✭
    Re: low-amp system for small sailboat
    Alan H wrote: »
    Honda eu1000i, huh? It's DC output is only 8.3 amps, but I suppose it would drive a 20 amp portable charger, eh?

    Right - use it's AC output, and a Deep Cycle battery charger. The deep cycle charger should be able to charge your batts @ 20 amp rate. An hour or 3 of that, and they should be close to full. Run gennie a couple hours in AM, and couple hours before retireing. As the charge tapers off, the generator will throttle itself back, the wonders of inverter generators !

    Maybe add a 3rd battery if you can fit it in ? Wont reduce your charge time (amps used have to be replaced) but will lessen the depth of the discharge.

    And if you get a really sunny day, run the gennie in the AM, you may have full batteries late afternoon. That will make the batteries happy.
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • mike95490mike95490 Solar Expert Posts: 8,288 ✭✭✭✭✭
    Re: low-amp system for small sailboat
    Andy did have quite a bit of generating capacity on the back end of the boat, I

    Can't be more than 200 Watts, and see his shadow over the panel behind him - the shadow of even a small line/stay will cut your charge current to nearly 0
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • icarusicarus Solar Expert Posts: 5,129 ✭✭✭✭
    Re: low-amp system for small sailboat

    Honda eu 1000 drives a Xantrex TC 20 almost at idle.

    Make almost no noise too. Bobbing on a boat might be a trick keeping it level etc. but I'm sure it has been done. Also, it only weighs ~30lbs so it is easy to pack about, (and store!)

    PS I've never used the DC side. I think the AC side and a Xantrex would give you more bang for your petro buck.

    Icarus
  • nigtomdawnigtomdaw Solar Expert Posts: 705 ✭✭
    Re: low-amp system for small sailboat

    Looking at this picture, stormy not very sunny a wind gen would be ideal:roll:
  • BB.BB. Super Moderators, Administrators Posts: 29,218 admin
    Re: low-amp system for small sailboat

    A couple of good mail order sites for Honda Generators:

    Wise Sales
    Mayberry

    Both require you to call for pricing--but they are very friendly and deliver quickly (and no CA sales taxes).

    The eu2000i (1,600 watt continuous) was around $900 (including shipping) a couple years ago. As I remember, the eu1000i (800 watt continuous) was around $700.

    The eu2000i is rated for ~4 hours at 1,600 watts on 1.1 gallons of fuel (internal tank). At 400 watts and eco throttle, 15 hours on 1.1 gallons.

    Honda EU (electronic inverter type) family description... The DC output from these is not really too useful for your application (unregulated output designed to charge a single car sized battery).

    14 volts at 15 amps is only 210 watts--quite a bit smaller (and longer runtime to charge).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • System2System2 Posts: 6,290 admin
    Re: low-amp system for small sailboat

    About the wind generators... The race is usually about 16 days or so. It took me 16, almost 17 days in 1996. The 2006 race was deadly, lots of boats didn't get in until days 19 and 20!

    My understanding is that most wind generators don't kick up much juice until the windspeed hits about 12 mph, or so. Over 25 mph, they howl and generate scads of electrons.

    Along the California Coast (the first three-four days) we're usually broad reaching (meaning sailing partway between perpendicular to the wind direction, and dead downwind). So during those days when it's often pretty windy, a wind generator will push out some significant amps. However after that, the prevailing wind direction goes more and more aft. This means that the boat is sailing in the same direction that the wind is blowing. If my boat is doing 10 knots downwind, and with a spinnaker up it certainly can maintain that speed for a long time, then it would have to blow over 22 knots to get those required 12 knots of breeze to get the wind generator to get going. To really pay off, it's going to have to blow more like 27 knots or more, but at that point my boat is going at 14 knots...so...uh... you see the dminshing returns, here? Gentlemen and ladies, I really hope it doesn't blow 30-35 knots all the way to Hawaii. I *really* don't want to work that hard! past results from guys who've used wind generators on this race haven't been all that great, though whoooiiieee do they crank out amps during the squalls that breeze in over Hanalei Bay.

    Wind generators work great going upwind, and in the anchorage. They're not so good on fast boats going primarily downwind, that's one reason (among others) why you don't see them on the Open 60's and so on.
  • System2System2 Posts: 6,290 admin
    Re: low-amp system for small sailboat
    icarus wrote: »
    Honda eu 1000 drives a Xantrex TC 20 almost at idle.

    I think the AC side and a Xantrex would give you more bang for your petro buck.

    Icarus

    OK, gonna go hunt down the Xantrex charger.
  • nigtomdawnigtomdaw Solar Expert Posts: 705 ✭✭
    Re: low-amp system for small sailboat

    See I learnt something else today wind not so good when your running with it:blush:
  • System2System2 Posts: 6,290 admin
    Re: low-amp system for small sailboat
    nigtomdaw wrote: »
    See I learnt something else today wind not so good when your running with it:blush:

    That picture of Andy on Foolish Muse was probably taken as he was working his way out the Golden Gate after the start of the race. See the Golden Gate Bridge in the background? From the start line to the bridge is an 6 mile sail to windward.....however, fortunately, there's 2120 miles to go after that point!

    It can blow like stink in the Bay, but be whisper quiet, 2 miles offshore, and that's exactly what happened that year. However, the low cloud cover persisted for *days* in 2006. In 2004 we sailed out the Gate into a 35 knot Gale, and in fact the one guy who had a wind generator reported that the generator more than kept up with the autopilot during those days. After they sailed out of the gale, though, the wind generator basically did nuttin' until he put the anchor down in Hanalei.

    you guys are gonna know more about this race than anybody but the folks who sail it, here pretty soon.
  • TelcoTelco Solar Expert Posts: 201 ✭✭✭✭✭
    Re: low-amp system for small sailboat

    Ya know, I think I'd be suggesting a water driven generator instead of a wind driven. As you say, the wind has to be blowing quite a bit faster than you are moving to get any good generation for you. But, as long as you are moving, you'd be able to run a hydro setup, just by bolting it to the side of the boat. No matter what direction you are moving, the water is going to be moving under you. This would work along the same principal as an emergency generator on an airplane, in which a prop driven generator will be dropped out of a hatch to provide emergency electrical power to the plane when the engines are dead to maintain controls, ect. In some cases these gens are powerful enough to restart the plane's engines. A small generator over the side, properly designed and installed in the right location, would not put much drag on the boat and would provide a 24x7 charge to you. Since it would be a 24x7 charge, it wouldn't need to be that big, either. Might even be able to just put a small paddle off the rear of the boat with an alternator built to operate at the low RPM levels you'd be getting.

    Course, I make this suggestion without knowing what the rules of the race are, this sort of thing may not be allowed.
  • nigtomdawnigtomdaw Solar Expert Posts: 705 ✭✭
    Re: low-amp system for small sailboat

    The need for speed may make it unpopular, but I agree Captain Kirk it seems logical:-)
  • BB.BB. Super Moderators, Administrators Posts: 29,218 admin
    Re: low-amp system for small sailboat

    One place I found in the last thread said that there is around a 50 lb drag from a towed water turbine. Probably not the best for a racing boat...

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • System2System2 Posts: 6,290 admin
    Re: low-amp system for small sailboat
    Telco wrote: »
    Ya know, I think I'd be suggesting a water driven generator instead of a wind driven. ..................................
    Course, I make this suggestion without knowing what the rules of the race are, this sort of thing may not be allowed.

    The race rules would allow this, but think about it this way... Good engineers have calculated that a cruising boat with a fixed (not folding or feathering) propeller lose 4-6 hours in transit time during the trip just from the drag of the propeller. That can easily be 2-3 places in the standings. OUCH. Double ouch when the prop is actually turning! (don't ask me why the drag is worse when the prop is turning, it makes no sense to me)

    There are commercial water-towed generators marketed for cruising boats who don't really care about a minor loss in speed, though and by all reports they work very well, though they've lessened in popularity in the past decade or so. ;)
  • BB.BB. Super Moderators, Administrators Posts: 29,218 admin
    Re: low-amp system for small sailboat

    A stopped prop going through air (or water) is in a "stalled" condition. Turbulence across/around the surface--more like just holding a flat shape against the flow.

    A turning prop (water or air) is actually creating lift and turning lift/rotation into rotational energy (either from the motor to move vessel forward, or driving the motor as drag). Much more drag (or thrust) than a stopped prop. Also think of the "swept" area of the blades vs the lesser area of stopped blades.

    Lastly, a "feathered" prop folds (ship) or turns edgewise (aircraft) to the air flow to reduce drag.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • nielniel Solar Expert Posts: 10,311 ✭✭✭✭
    Re: low-amp system for small sailboat
    nigtomdaw wrote: »
    Looking at this picture, stormy not very sunny a wind gen would be ideal:roll:

    i guess i have to remind people that they aren't just cruising the ocean as this is a race and such things as wind generators or gennies in the water would bog it down and there may not be room for it as he needs his sails. the only possibility would be for somebody to design a very small savonius type on top of the mast that could kick a few hundred milliamps normally from a generator that may be designed for a few amps. the buckets would have to be small enough not to be a detriment. more power would be reliably obtainable from solar and keeping pvs scattered on both sides and maybe the back too like andy did would insure a charge from some pvs. his pvs were small and more manageable for customizing to the area he needed them in and i believe each was 10w if memory serves. i don't remember offhand how much he had, but 200w seems close.
  • TelcoTelco Solar Expert Posts: 201 ✭✭✭✭✭
    Re: low-amp system for small sailboat
    niel wrote: »
    i guess i have to remind people that they aren't just cruising the ocean as this is a race

    Ya know, that's 100 percent correct. Race conditions, race equipment. Unfortunately I saw this more as a conservation issue than a race issue.

    New suggestions: I think I'd do away with any kind of renewable energy setup on a race-only boat. The weight/drag vs energy production might be worthwhile on a pleasure craft, but not worth it on a racer.

    Instead of solar panels, put the weight towards building a sound proof enclosure for a high efficiency generator that can carry your entire load while charging the batteries. A high quality small car muffler in place of the tiny factory muffler will also cut the sound by quite a bit, just so the pipe diameter is close to the same. Also, installing the generator so the exhaust can point upward, to the side and off the rear of the boat will keep sound from being reflected back off the water and prevent exhaust fumes from wrapping back into the boat. Deep cycle batteries will also let you discharge far deeper than regular batteries without killing them, so when the generator is running it can put more juice into the recharge. Might even take your load off the batteries altogether by hand steering during the charge process.
  • nielniel Solar Expert Posts: 10,311 ✭✭✭✭
    Re: low-amp system for small sailboat

    the weights of pvs are somewhat irrelevant as they could save even more by throwing their hf radios overboard too in both power consumption and weight.(sarcasm) the pvs won't create drag in the water or air and is why their weight isn't as important. no carbon monoxide worries either. thin films can do this with lighter weights if it is important as many gennies and the fuel needed for them will weigh very heavilly too. when being in the pacific ocean that long i'd rather have pvs as that genny becomes dead weight when there's no heavy fuel left to run it, but pvs will still kick out power. this jaunt doesn't happen over just a day or 2 and i'd certainly be leary with that much flamable liquid on board in the middle of the pacific ocean. some common sense here please.
  • TelcoTelco Solar Expert Posts: 201 ✭✭✭✭✭
    Re: low-amp system for small sailboat
    niel wrote: »
    the weights of pvs are somewhat irrelevant as they could save even more by throwing their hf radios overboard too in both power consumption and weight.(sarcasm) the pvs won't create drag in the water or air and is why their weight isn't as important. no carbon monoxide worries either. thin films can do this with lighter weights if it is important as many gennies and the fuel needed for them will weigh very heavilly too. when being in the pacific ocean that long i'd rather have pvs as that genny becomes dead weight when there's no heavy fuel left to run it, but pvs will still kick out power. this jaunt doesn't happen over just a day or 2 and i'd certainly be leary with that much flamable liquid on board in the middle of the pacific ocean. some common sense here please.

    Yes, some common sense. This is an organized race, not an exploration cruise. The path is more or less charted and race officials should be in the area making sure nobody gets into trouble and making sure nobody's cheating. He knows how much juice he needs, what he needs is the most compact, lightweight, efficient way of getting it. And that way would be a single diesel generator. What I'd want for emergency gear is a satellite telephone, a GPS coordinate scanner, a few extra batteries and a few days provisions so I could call for help and tell them where I was. If something goes wrong he loses the race, calls for help and tries again next year. And weight is never irrelevant, all else being equal a lighter vessel is a faster vessel. Mind the ounces and the pounds will follow, and PVs that only work when the sun is at the rear of the boat due to shading are next to useless, and therefore are unnecessary weight in a racing sailboat.

    If we were talking about a pleasure cruise or an exploration cruise, where you'd be out on your own without anyone knowing where you are going, then some PVs and some sort of wind generator would be a good idea, but not for a race.
  • nielniel Solar Expert Posts: 10,311 ✭✭✭✭
    Re: low-amp system for small sailboat

    that will be up to each individual racer as to what he will go with i suppose as no matter what, weight to produce power will be present. how much power and weight from whatever method they wish will be up to them. i agree that the foolishmuse should've spread out the pvs elsewhere, but it still worked for him well. the satellite phone i think is an excellent idea, but many of them will not part with a good marine radio. i don't think the judges are there to hold everybody's hand like you think as by the time the judges run across them dissaster may have already occured. it is not risk free by no means and if alan could shed more light on what he really wants then we can kick more advice to him and he'll decide how he'll go about it.
  • System2System2 Posts: 6,290 admin
    Re: low-amp system for small sailboat

    Hi, Long time, no see gang, but I thought I'd check in and let you know how it went.

    OK, my solar set up: Panels: two new Kyocera 40 watt panels mounted on the stern rail, with fittings so I could tilt them. Truth is, I left them flat most of the time. ..and two used solarex 30 watt panels. One solarex was mounted over the companionway where it got sun about half as much of the time as the 40-watters, and was shaded by the boom more than I'd wished. The four panel wasn't mounted at all. I had it on a long cord and just put it in the cockpit during the day, in the sun and tied it to a cleat with a small cord so it wouldn't crash around.

    Regulator: Morningstar Dual Battery Charge Controller 25 Amp (though my array only put out, at most about 9 amps).

    Batteries: two, 90 amp-hour wet cell, deep cycle marine batteries.

    Weather conditions: Gray, gray, gray to the point where I actually commented in disgust one night on the radio..."This is the sailing vessel, Ankle Biter, checking in with the Singlehanded Sailing Society's singlehanded race to NORWAY..."

    Honestly, it was depressing during the first half of the race, it was much more overcast than the normal year. We didn't see regular sun until about day ten, and it was only really sunny all day long from days 13 - 17 (for me). When we did get sun, at least both of the 40-watt panels and one 30-watt were in full sun for 5-6 hours a day and partial sun or sun with always moving shadows on the panel...or sun at an oblique angle, for 2-3 hours more than that..

    Draw:

    autopilot: about 1 amp draw. I didn't use the autopilot for the first six days, but rather relied on my windvane steering system. When the windvane exploded, I then used the autopilot from 18-24 hours a day.

    running lights: I have replaced the usual incandescent lights with LED's. This is a MASSIVE savings, as each incandescent bulb burns up about an amp, and there's two on the boat (at least 20 amp draw per day) whereas the LED's burn up about 0.1 amp.

    GPS: I had handhelds that used AA batteries, but i ran the hard-wired GPS all the time, often 18 hours a day. It draws 4 watts max at 13.8 v, so I figure roughly 0.3 amps

    AIS: this is a vessel identification system. Basically it's a VHF radio receiver...it doesn't broadcast at all. Draw is about 0.1 amp.

    VHF radio...I barely used it at all.

    SSB (HF) radio: I checked in regularly twice a day, which took about 2 minutes of broadcast time and as much as an hour of listening time. If I was stressing over low batteries I'd listen to the whole check in and write down everybody's position, but not talk at all besides relaying my position. If everything was juiced up pretty good and the batteries were over 12.6 or 12.7 volts I might broadcast and chat for 5-8 minutes of transmit time.

    Laptop and satellite phone: I don't know the draw on the phone but I had to recharge it several times during the trip. I used the phone to send/get e-mail and weather files. I'd hook up a portable 400watt inverter to one of the batteries and charge for about an hour. This would drop that battery from 1.6 -12.7 volts down to below 12. The same went for the laptop. I never ran the laptop directly from the inverter, I would always run it from the battery, and then plug it in to charge it.
  • System2System2 Posts: 6,290 admin
    Re: low-amp system for small sailboat

    OK, now you know the equipment on board, now, how did it go?

    This is a race from San Francisco to Hawaii, so there's nobody out there but you and your fellow racers...a few fishing boats....the very occasional container ship...and this year, a few boats from the Pacific Cup.

    My plan has been to use the Windvane to steer the boat during the first few days and minimize electrical draw during the part of the race that was likely to be cloudy. I didn't know that the "cloudy" part would be the first HALF of the freaking race! Anyway, so that draw; the autopilot, was off during the worst of the overcast. The batteries slowly lost charge as the days went by, but I had no issues connecting to the rest of the fleet by SSB radio, and could broadcast 100-150+ miles, no problem.

    Eric on Polar Bear had the same type of Boat as Andy had (Foolish Muse) in 2006. His solar array was probably more like about 180 watts and he said that it was keeping up with his useage even during this period of the race, and Eric did not have a windvane. He ONLY had autopilots.

    On Day nine I discovered that my windvane had self-destructed, so I took the oar out of the water and ran the rest of the race on autopilots and hand-steering.

    On day eleven I was sufficiently worried about low batteries (both were below 12 volts) that I got out my little generator. It's a model that used to be made by Coleman, it's no longer marketed, but it CLAIMS to have a 50 amp charger in it. It puts out diddly 110 (100 watts?) but wowee does it charge the batteries. Anyway, despite having it serviced before the race, it ran for 40 minutes and died. It probably put about 30 amps back into the port house battery before ending its life. That left me dependent on solar.

    The next day we started getting a lot more sun, and by two days later my stress level decreased and we were totally fine for the rest of the race. I monitored charge on the batteries two-three times a day and they varied between 12.3 and 12.9 volts.

    In retrospect, I wish I'd had the two 65 watt Kyocera panels that I originally bought, but sent back because I thought they were too big. 65 + 65 + 30 + 30 = 190 watts, which should be plenty. On the other hand, as long as I had the windvane for steering, battery charge was much less of a panic issue.

    In addition to basic running lights (useless on the ocean) I also ran a small strobe light hoisted up the rigging, that was connected to a 6v lantern battery. That battery lasted the whole trip and I had two spares..

    With windvane steering, battery-operated, handheld GPS, paper charts (not electronic) and small battery-operated strobe lights to light up the boat at night (and lots of extra batteries) it's entirely possible to cross an ocean with NO electrical system. As it was, my solar array worked out OK. It might not have been so good if I'd lost the use of the windvane several days earlier.

    Note that I have a very bare-bones race boat. I do not have refrigeration, for example, and I do not use electronic charting. I am always conscious of electrical useage and while I don't obsess over it, I take care to not be wasteful with what I've got.

    I hope this is helpful to others that may come here for similar advice, in years to come!

    Alan H
  • BB.BB. Super Moderators, Administrators Posts: 29,218 admin
    Re: low-amp system for small sailboat

    Alan,

    Glad to hear you survived!

    Always very interesting to read how the "single" people are living their lives!

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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