My Scamp is now a solar charged creature of the sea.

[Doug SC]

I guess all sailboats are solar powered by the wind which is the sun's doing. I haven't yet gone electric with my motor but could run a trolling motor I have. I just finished adding a 100W solar powered electric system with a 100Wh lithium iron phosphate battery to my Scamp sailboat for charging phones, vhf, GPS. rechargeable batteries, laptop, running/anchor lights, USB fan, 300W inverter, and 200W heater, and lighted compass. It's now set up for extended all weather cruising within reason. This project was put into action when my camping, fishing, paddling, sailing, friend Frank gave me a used 100W solar panel. He replaced it with new ones on his RV. I also added a simple tiller restraint. Here are a few photos of the arrangement.

In this photo you can see where the solar panel is mounted. I have the end of an old wooden broom stick mounted under the transom deck holding the panel in the same arc as the deck. The panel corners at the stern are tucked under the deck and the cockpit side is tied to the docking cleats.
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Here you can see the end of the broom handle which comes about two thirds of the way out under the panel. You can also see the rope tiller tamer with eye strap and cleat to tighten down on the line
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This is a view of the lighted compass mount and the covered USB/voltmeter and DC car lighter outlets. I picked up the compass used for a good price, but it lacked a $30 mounting bracket. I used a left-over piece of plastic cutting board I used on another project to mount the compass. The battery and wiring are behind the forward bulkhead. The need help on the flotation cushion is a truism in my case. I bought it when we bought our first canoe about 1976 a couple of years after we married. It has seen a lot of water miles pass under boat hulls.
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This is a view of the battery and bus bar. I use the connector at the bottom right to disconnect the battery from the controller. I have a 30-amp DC lighter outlet directly connected to the battery so I can run a 200W heater. The controller is 20 amp limited so I disconnect it to run the heater. I have the battery sitting on two 2x4 joist under it and strapped with 3 nylon straps. It won't budge. I plan on buying a battery box as the two I have are group 24 and I need a group 27. Go figure! when I do I will then zip tie the wires together.
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Now I am just waiting on a break from the rain and below freezing weather to pass for a few days of sailing and camping on board.

[Charles Brennan]

Doug, Congrats on increasing the micro-cruising versatility of the SCAMP, through electrical conveniences.
I was interested to see the battery mounted in front of the mast trunk; I hadn't thought of that.  I was trying to keep the additional battery weight as close to the ballast area, as possible. My anticipated location is a lot more vulnerable, if I ever capsize, or turtle the hull.  Will have to give that some more thought, especially while things are more or less in flux, in my current build progress.

I was gratified to see someone with enough sense to keep the compass along the center line of the hull, so the boat could be used to more easily see a rhumb line. 
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I never understood all the guys I see in the various SCAMP blogs and forums, off-setting their compasses off-center, like this guy:
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I'm currently building a wooden housing, to place my Optima mini Contest in front of the mast trunk slot, just like your compass is.

One concern:
I noticed all the DC sockets encircling the compass and wondered about your wiring.
Especially with all the conductors in the pic being run parallel and not twisted.
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Whenever current travels through a conductor, a magnetic field is generated, like Hans Christian Ørsted first figured out in around 1820.

When I relocated the battery in Urchin to deal with weight and balance issues, I had to twist the battery wires (6 twists per foot) to prevent the compass from trying to "jump" off it's gimbal, every time the lights or autopilot were switched on.  To say nothing of observing sudden 30º course changes, when the tiller pilot was really cranking! 
It might become necessary to pull apart those parallel wires and then twist them around each other,  to break up any stray magnetic fields.

One mitigating factor is that magnetic force (the amount of Gauss) is an inverse-square function.  Which is to say, every time you double the distance away from the magnetic force, the Gaussian effect is the square root of the previous measurement.

Simple Test:
Plug everything in and switch stuff on and off in various combinations, (especially that 200W heater!) while watching the compass.
If any deflections are observed, first try relocating some of the wiring away from the compass.
Remember, a little distance has a strong deterrent effect on magnetic fields.
If none of that helps, you may have to go the twisted-wiring route.

Hope this helps,
Charles Brennan

[Krusen]

  Good catch, Charles.
The red black cables do not need to be pulled apart to twist them, just disconnect the end, and twist the cable as is.  6 turns per foot should work well.

As much as possible, run the wires as far as possible from the compass, and distance will decrease the disturbance, as Charles said.

For both of you, with the severity of Lithium battery fires, consider a metal strap arrangement to grab and pull the battery out, and an easy disconnect plug connecting the boat system to the battery.  Those fires seem to develop slowly, so you should have time to get it over the side before it causes serious damage.

Krusen

[pgandw]

For both of you, with the severity of Lithium battery fires, consider a metal strap arrangement to grab and pull the battery out, and an easy disconnect plug connecting the boat system to the battery.  Those fires seem to develop slowly, so you should have time to get it over the side before it causes serious damage.

This false information keeps showing up.  LiFePO (lithium phosphate) batteries - which are sold as lead acid replacements - are a different chemistry than the lithium ion batteries in your phone, portable tools, and so on, and DO NOT catch fire.  The wires outside the battery need to have proper size fuses/circuit breakers to protect the wiring, not the battery.  LiFePO batteries are widely used in boats, RVs, and similar situations to replace batteries because of their safety.  However, most LiFePO batteries are not suited for use for engine starting of more than a 10hp motor.

Lithium ion batteries are a whole different animal, and can catch fire.  Yet they are still used in cell phones because of the extra energy density.

Fred W
Stuart Mariner 19 #4133  Sweet P

[Norm L.]

Agree on these marine acceptable batteries. Also, higher power density and longer recycle life span.
I think they are heavier and more expensive.

Doug, where will you put the microwave?

[Doug SC]

Agree on these marine acceptable batteries. Also, higher power density and longer recycle life span.
I think they are heavier and more expensive.

Doug, where will you put the microwave?

Norm, they are half the weight of an equivalent lead acid which are heavy as "lead"! Yes, they are a different chemistry from lithium-ion batteries. I saw it stated that there have been no boat fires caused by lithium iron phosphate batteries. I don't know if that is so, but they are safer. However, a metal wire cage or strap with a ring and a bailing hook or hand gaff would be a good way to toss one if needed thanks for that advice Krusen. And I wondered why the small wires coming off the compass where twisted. Duh! Now I know. I learned something there. I did worry about the other wires That run to the solar panel.

Well, the twisted finger of fate turned in my direction for a change!   When we got home this afternoon, I decided to do what CB suggested and see what happened with the compass when I ran stuff like the heater and fan. I did a couple of measurements to see how far the compass was from things. The compass center hangs 5 1/2" back from the face of the front of the "veranda" and about 14" from the bulkhead behind it. The DC outlets are about 13" from the closest point to the compass. Best I can tell is the positive battery terminal is 30" from the compass and the buss bar 36". The metal tape measure near the compass made it dance the tango. I wanted to check the bearing of the boat compass against the compass on my phone. So, I lined up the compass on my phone with the center line of the boat and boat compass. The boat compass is marked in 5-degree increments and the phone was by 1-degree. The best I could tell was the boat read 321 or maybe 322 while the phone was 321. Yippee! Next, I ran the fan on all 3 speeds and even moving it around the compass. The compass reading didn't change. Then I plugged in the heater to the inverter and got the same result. The Compass was still on 321 or maybe 322. the battery was fully charged, and the sun was low, but the solar panel was connected. I don't know if in full sun and charging if that will mess with the compass.

I was relieved that I didn't have to try and disconnect, twist, and reconnect all the difficult to install wiring in an uncomfortable tight space. CB I strongly suggest if you want to avoid being inspired to come up with new combinations of the profane that you preinstall before closing in the area you plan to place your electronics.

The fan running on high mounted close to the compass.
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The fan turned off.
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The inverter and heater running where they most likely will be placed
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[Charles Brennan]

Doug, That is indeed, good news to hear.  Based on what you've posted to date, I wouldn't sweat the solar panel.  Your 200W heater draws roughly 16 Amps from your inverter conversion and your 100 watt solar panel is only capable of sending around 8 Amps maximum, at full sunlight at high noon.  So it's doubtful that it is going to influence the compass, if the inverter/heater hasn't.
Guess I'm just the Lucky One, that these kinds of things always happens to! 

One of the main reasons I have deviated from the SCAMP build manual is precisely because I intend to pre-wire the entire boat, before the sole goes down and before the deck goes down, etc.  I have no illusions about being limber enough to crawl around in there and using the Mangled Monkey Yoga Pose, a position well known to all sailors who've ever had to climb under bench seats into a lazarette to reach and tighten a teeny-tiny screw in the darkness down below.   

Now about these LiFePO4 batteries: 
Y'all remind me of the ancient fable about the 5 blind men in India encountering an elephant and each had a different impression based on what part of the elephant, they were experiencing. 
And just like those guys, ALL of you are partially RIGHT and ALL of you are partially WRONG! 

Starting off with incorrect definitions: 
Lithium ion metallic batteries, versus non-metallic Lithium ion batteries.
Metallic Lithium ion batteries have a flammable electrolyte and are prone to thermal runaway.
This can happen when the battery is damaged, punctured, overcharged, or exposed to high temperatures or direct sunlight.  And once they go up, it's Hell to put them out again.
I believe this is the technology, Kruse'n was referring to and his advice was spot on.  (For that technology.)

Non-metallic Lithium ion battery technologies like:
Lithium Iron Phosphate (LiFePO4)
Lithium Nickle Manganese Cobalt Oxide (NMC)
Lithium Manganese Oxide (LMO)
Lithium Cobalt Oxide (LCO)
Lithium Nickel Cobalt Aluminum Oxide (NCA and battery of choice, for Tesla.)
Lithium Titanate (LTO)
NONE of these 6 types of Lithium technology are particularly prone to the previously listed horrors. 

Now, unless Y'ALL SPECIFY EXACTLY WHICH Chemistry you're talking about; NO MORE PRONOUNCEMENTS FROM ON HIGH!! 
Whew! NOW I feel better! 

Since Kruse'n and I come from similar technical backgrounds, we have similar thinking about mitigating disasters.
So his advice: "consider a metal strap arrangement to grab and pull the battery out, and an easy disconnect plug connecting the boat system to the battery." is something I was already planning for.  I intend to use Anderson connectors in the 120 Amp (or so) range as quick disconnects to deal with the unforeseen.  I am not going to use a metal strap for fear of arcing, (more, later on) believing that a nylon strap will allow me to move the battery quickly (before the strap burns through) due to the Anderson connectors.
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Fred W's advice: "This false information keeps showing up.  LiFePO (lithium phosphate) batteries - which are sold as lead acid replacements - are a different chemistry than the lithium ion batteries in your phone, portable tools, and so on, and DO NOT catch fire.  The wires outside the battery need to have proper size fuses/circuit breakers to protect the wiring, not the battery.  LiFePO batteries are widely used in boats, RVs, and similar situations to replace batteries because of their safety.  However, most LiFePO batteries are not suited for use for engine starting of more than a 10hp motor."

Was completely correct, as far as his impression of the technology goes, but it doesn't go far enough.
LiFePo4 batteries are generally considered to be "fire safe" because they have a very stable chemistry and a very low rate of thermal runaway, which is a condition where the temperature of the battery increases rapidly, potentially leading to a fire.

BUT!!  If the "safe" LiFePO4 is punctured (for whatever reason) and starts leaking electrolyte, then is exposed to sparks, you CAN and you WILL ignite the electrolyte and you WILL have a Fire on your hands!! 
And NOW, you're trying to console yourself, that the LiFePO4 fire ONLY burned at 185ºC - 270ºC!!
Whew!    Good thing it wasn't a metallic Lithium ion fire, burning 4 times hotter, at 700ºC - 1000ºC!!
THAT woulda been BAD!!! 
Gimme a break. 
A lithium battery fire of ANY technology type, is going to "China Syndrome" my hull. 
Unless I can quickly manage to Deep Six it.

"But, Charles!" (You say.) "HOW can you puncture a LiFePO4 battery AND get sparks?"
Simple.
I'm going to have two 100 A/Hr LiFePO4 batteries on my SCAMP.
If one is punctured and the other is still providing sparks, there's my Disaster.
On those "safe" LiFePO4 batteries.

Something not discussed yet, is the (IMHO) general false sense of security of LiFePO4 batteries, due to the wizardry of their vaunted BMS (Battery Management System) circuitry.
These gadgets keep thermal runaway from happening in the first place, shutting down if the temps are too high, if there is a short circuit, if there is a polarity reversal, just all kinds of good reasons to shut down, if everything is not running 100%

Custodiet ipsos custodes?  (Who guards the guards?)
If the BMS circuitry fails catastrophically, all bets are off.
So what could cause that? 
An IP65 rating on a battery, that might end up in a flooded compartment, could do exactly that.
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See any conformal coating, or waterproofing, on this BMS module? 
Me either. 
This dinghy is capable of capsize and in bad enough circumstances, capable of turtling over, entirely.

On the Worst Day Ever, the hull capsizes, the batteries flood, the BMS circuitry fails, one battery gets punctured, while the other battery (no longer protected by its BMS) merrily spits sparks all over the place.
At which time, I figure I have between 20 and 40 seconds to:
1) Open the forward sole hatch.
2) Rip apart the Anderson connectors.
3) Disconnect my battery tie down straps.
4) Grab the batteries by their handle straps.
5) Jerk them clear of the sole.
6) Heave them over the side. 

I have a clear-eyed, hard-nosed, and skeptical, view of Reality and an unwavering faith that:
God Does Not Repeal The Laws Of Physics, For Anyone.
This is why I neither completely accept Kruse'n's dire warnings, nor completely accept Fred W's "it's all good" defense of LiFePO4 batteries.

Back in another life, I used to test electronic circuitry; in fact, I was quite good at it. I never failed to astound the engineers, in getting equipment to fail (sometimes, spectacularly!) in ways the engineers NEVER envisioned.
This is why I am distrustful of the Latest, Greatest, Newest, Super-Duper Technology and am (always!) hedging my bets and mitigating circumstances, as best I can, everywhere I can.

Hope this clarifies,
Charles Brennan

[Doug SC]

I spent a considerable amount of time perfecting the "Mangled Monkey Yoga Pose" and its many advanced variations during this project.

[Riley Smith]

The mast step and first bulkhead on the catboat needs painting but I can't get there anymore! LOL!

[Spot]

The mast step and first bulkhead on the catboat needs painting but I can't get there anymore! LOL!

I think you need a grandchild, some paint, a brush, and the promise of something they like as a reward for the task...

[pgandw]

This dinghy is capable of capsize and in bad enough circumstances, capable of turtling over, entirely.

On the Worst Day Ever, the hull capsizes, the batteries flood, the BMS circuitry fails, one battery gets punctured, while the other battery (no longer protected by its BMS) merrily spits sparks all over the place.
At which time, I figure I have between 20 and 40 seconds to:
1) Open the forward sole hatch.
2) Rip apart the Anderson connectors.
3) Disconnect my battery tie down straps.
4) Grab the batteries by their handle straps.
5) Jerk them clear of the sole.
6) Heave them over the side. 

I have a clear-eyed, hard-nosed, and skeptical, view of Reality and an unwavering faith that:
God Does Not Repeal The Laws Of Physics, For Anyone.
This is why I neither completely accept Kruse'n's dire warnings, nor completely accept Fred W's "it's all good" defense of LiFePO4 batteries.

Back in another life, I used to test electronic circuitry; in fact, I was quite good at it. I never failed to astound the engineers, in getting equipment to fail (sometimes, spectacularly!) in ways the engineers NEVER envisioned.
This is why I am distrustful of the Latest, Greatest, Newest, Super-Duper Technology and am (always!) hedging my bets and mitigating circumstances, as best I can, everywhere I can.

Hope this clarifies,
Charles Brennan

Charles

I don't disagree with you at all.  Having flown helicopters in non-desirable circumstances I simplify the world into 2 states:
- what can go wrong will go wrong, probably when you least expect it.
- what you never imagined could go wrong, will go wrong, and will scare the crap out of you.

In my Mariner, the most likely imaginable emergency situation is me going overboard unintentionally while sailing solo.  The 2 most likely causes are capsizing the boat and my old-age clumsiness.  The best chance of survival in the water can be enhanced by:

• WEARING my life jacket.  I have decided to gift myself with a water pressure activated inflatable PFD
• Having an SOS strobe and a PLB attached to the PFD (gonna gift myself again).
• Minimize use of the Tiller Clutch (so the boat will round up and wait for me).
• Checking that I can release and reboard using the boarding ladder on a Summer day.
  

My goal is to prevent DW from filing a claim against my life insurance.

The Mariner is supposed to have flotation - I have seen the foam blocks under the cockpit and under the V-berth.  There is also foam in the mast, but I have less confidence in the mast/boat not turtling.

I currently don't have an electrical system, but intend to install one this summer.  Which is why I read your thread with such interest.  I intend to use a single 150AH LiFePO battery because I really, really dislike batteries in parallel.  I have seen mismatched parallel lead acid batteries start a really pretty blue-flamed fire in the battery box on a camper that I was able to put out by cutting the parallel cables with linemen's pliers.  The large capacity of the battery is to enable slowly recharging the electric outboard.  I will be using a 50 or 100 watt solar panel, based on what will fit on the foredeck and/or across the cockpit seats in the rear.

Thanks for the inspiration and ideas.

Fred W
Stuart Mariner 19 #4133  Sweet P

[Grith]

Great discussion.
Our much larger Imexus 28 is now virtually a solar/lithium powered liveaboard whilst remaining fully trailerable and one person rig and launch/retrieve capable.
We have over 1000w of permanent solar panels with a further 320w of deployable foldable panels. These charge our just over 6000kwh of lithium batteries comprising of two EcoFlow Delta Max 2 powerbanks and a 100ah high charge/output capable computer monitored BMS with Bluetooth communications back up and anchor winch lithium battery and a lithium house 12v battery.
We still have our conventional high cranking amps outboard starter battery.
We cook via 240v induction, have 240v hotwater, a 12v/240v compressor fridge and separate freezer, charge our auxiliary torqeedo 1103 batteries (used on both the yacht and our dingy) and have a variety of occasional use 240v appliances including 24v 100-300wh airconditioning and 240v 300wh ceramic heater.
To make trailering and setup/pack up easier all the solar panels remain erected during trailering including for some very long distances.

[Norm L.]

Graeme.
That is set up like a houseboat! With sails.

Of joy is that Mardi Gras is March 4 and Footy starts March 6.

[Doug SC]

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[pgandw]

What a waste of beads, when they can be used to pay for the sights on Canal and Bourbon St.