another solar question, beating the dead horse

[aronhk_md]

skidgear - you are assuming a lot just because the batteries in a pack "bulge". All materials expand and contract with temperature changes including the concrete on a sidewalk, metal sections on a road surface and the list goes on...and it does not take huge temperature changes to do it.

You knock "internet experts", but many times some of those people know more than the organizations you seem fond of. Same thing happens in medicine. I have seen patients and parents of patients who have researched an illness or topic so extensively their knowledge surpasses that of most physicians who are "experts" in their field.

If you think this is the rare occurrence, think again.

Often times regulatory agencies have relatively inexperienced and poorly informed people making decisions. Even where experience and knowledge are adequate generally speaking, they aren't necessarily cutting edge. And then there is the FACT that many times regulations and guidelines are placed solely to benefit whomever had deep enough pockets to lobby and place them.

If your worry is the boater in your marina who managed to piece together a "cutting edge" solar array and battery bank, then nothing anyone can say here is going to make your nights less restless.

I personally am less worried about that sharp thinker than I am about the droves of beer drinking yahoos that know what a throttle is and have a wallet capable of paying for a boat. And those holes in the water come in all sizes, not just runabouts/jetskis.

I'll take the thinker/tinkerer any day as a neighbor in the slip next to me. Yes, without regulation forcing his hand. As for the beauty contest you are referring to...maybe you think there needs to be guidelines regarding aesthetics of a vessel too? Or perhaps regulations?

"buy used up packs and pick out the "good cells"...really? Does every yahoo understand how to do that safely? Are the cowboys going to carry around a sign on their boat that says they're stupid? Who defines what a minimum safe system should look like....the average of opinions from wild eyed enthusiasts on internet forums? It's not just about you. You bet I have a concern about the uninformed. Again, if they keep their kluge at anchor out in the middle of the harbor, please have at it."

I go back to some statements about other potential areas we should maybe regulate so you can sleep soundly at night. I think considering your concern for safety we should DEFINITELY regulate the usage and sale of used tires for the vehicles we drive. After all, they are 2 plus ton vehicles hurtling down our roads often times in opposite direction to the vehicle you are driving, separated by a little white or yellow line and at closing speeds often in excess of 130 mph.

Think of those millions of craigslist ads for used tires while you head down the road toward the marina, where deckofficer has his awfully dangerous boat berthed next to yours. Who checked those used tires and made sure they were safe to be put back on the road???!!! Just curious if you have a crusade for safety there too?

Just one of a zillion potential hazards we live with that someone with a crusade could point to logically as a serious threat to life, and limb. An area that could really use regulation, forget guidelines! Inspection lanes passing a car through every few years as we have in many states are not nearly sufficient to eliminate/reduce the danger. They weren't really designed to.

Dangers exist in your own home, before you ever decide to open the door and step outside. And yes, some of them should be regulated. But it is impossible to eliminate them all, and ridiculous to try.

Regulation in this country has gone way beyond anything sane. Its time to triage the "patient" and stop the hemorrhaging before it dies.

And once again the thread goes off course, and I am partly to blame.



Ebaugh - 2 things

1) The drain you are talking about running twin 16,000 BTU units, one at 100% during the day is far greater than what I need. I am quite happy to zone the A/C and live in one are of the boat primarily at a time. If I want to head into the stateroom I'll turn on the A/C for a few minutes ahead and use a fan till it cools. I know this boat was comfortable with a 12,500 and 8,000 unit from the prev owner.

I am surprised though to hear that your A/C unit runs at 100%, never cycling the compressor off. It sounds as if that unit isn't sized right for the area it is cooling or it isn't working correctly?

2) I factored in plenty of "cloud" time when figuring out the cost of running a gen set. But I also have to factor in the absolute need to use the generator to a degree even if using solar for most needs, and I really didn't do that. Lets say you get a week of cloudy weather, but its still hot and sticky as hell. Going to want to run the A/C.

But hopefully during those times the A/C isn't under the same heavy load too. Still its an expense I hadn't added into the solar side......and need to. lol

--------------------------------------------------

Another item I plan to have on the boat is a misting system on the upper deck. I wanted it just because I love them around the pool...why not have them here too? But it didn't occur to me until some of the posts here that they could potentially keep the cabin cooler when inside. Interesting thought.

Another 2 factors that may work in my favor, and not everyone has this advantage...A) my upper deck is completely shaded. The sun will still shine in once it begins dropping toward the horizon, but the worst hours of the day I'm well shielded. B) The boat is all aluminum. The white cabin sides will stay cooler than fiberglass, and much of the hull will act as a heatsink using the water it contacts. The opposite holds true in winter, but I have another plan for heat besides electric.

Solar as a dollar wise smart main power source is still a "what if" scenario until I know much more though. Enjoyable to discuss it certainly is. lol Meantime I am looking at equipment out there, what things do, and why.

 

[twistedtree]

If the FAA and aviation industry groups waited on a body of experience from do-it-yourself experimenters in the fleet to establish special criteria for new or emerging technology, there would be a lot smoking holes around the world. Most of the time they get it right because they approach new technology in a very conservative manner. Even so they got it wrong with the 787 (and for the umpteenth time I realize the chemistry is different). ABYC has actually been looking at this for quite some time (see the article in Boat U.S. magazine)...but I believe they're a bit behind the power curve.

I'm sure internet "experts" will be eager to mix it up some more.

All the innovation and engineering comes from the industry, and they need to demonstrate to and convince the FAA that their designs are sound. Usually it works. I think it's naive to even consider that the FAA figures out how to apply new technologies.

I totally agree that do-it-yourselfers result is a lot of serious hack jobs. Household and boat electrical systems are a prime example. But with new technology like LFP, you get some pretty smart people, often times trained professional engineers in their real life, leading the way to figure out how to apply new technology in a new way. We should encourage them.

Organizations like ABYC, whom, buy the way, I'm very much in support of, come in at a later time in the life cycle. At least that's how I see it. Their role is to be sure there are good guidelines for mass deployment where the people doing the work won't be as knowledgeable as the pioneers. Standards help ensure consistent application of best practices.

For most people, waiting for LFP to be considered and reflected in ABYC standards before using the technology is likely a good approach. But I also think it's great that TF and Cruisers Forum can bring together the pioneers for this application and help accelerate the overall adoption.

 

[FF]

I am surprised though to hear that your A/C unit runs at 100%, never cycling the compressor off. It sounds as if that unit isn't sized right for the area it is cooling or it isn't working correctly?

An air cond system that runs full time or almost full time is far better for comfort aboard than a huge thing that runs 15 to 50% of the time.

Air is recirculated by in the cooling process and it takes a bunch of times past the cold surfaces to knock the moisture out of the air , and lower the humidity.

Sounds like the folks that installed the system understood the unit doesn't just make colder air.

Locally at the River Forrest big buck storage facility the air cond consists of multiple units.

Redundancy , sure ,,but one smaller unit on ALL the time dehumidifies a hangar sized building , the others are used to play catch up for a few hours after the doors have been opened & closed.

To large an air cond unit may lead to zero comfort.

In refrigeration the new DC speed controlled cooling units would run 100% of the time if the engineers were alowed to set it properly.

Sadly owners think something is wrong if the unit is always on , so most are factory set to operate 85% of the time , as slightly higher speeds which costs more electric , but fewer service calls.

 

[aronhk_md]

FF, I do follow the logic behind what you are saying regarding humidity and temp maintenance. But I have to say I see systems all the time cycling off on a regular basis and doing a fine job in keeping humidity down and not fluctuating temps wildly. I do agree though that a system CAN be oversized and lead to quick cool downs that leave you feeling alternately warm, cold as well as not doing a perfect job on the humidity.

When you say, "Sadly owners think something is wrong if the unit is always on , so most are factory set to operate 85% of the time , as slightly higher speeds which costs more electric , but fewer service calls." I am thinking the engineers are sizing the units slightly bigger to account for things like a small reserve in cooling capability due to unknown factors in layout, use, etc. Sizing to run all the time using the smallest BTU unit possible does as mentioned lengthen the systems initial cool down time and recovery time after doors being opened or system off for a few minutes, not to mention potentially increasing greater temp variances between different rooms in the zone. It may even possibly allow temp variances in different parts of a large room.

Normally we have more than one unit on a larger boat, but each usually has its own zone, so we aren't sizing one for quick cool down and another for temp maintenance.

My guess without being an HVAC engineer is that there is a good "range" of operating cycling in a system that only has one unit that needs to do cool down AND temp maintenance, and planning a system that only runs at 85% probably allows some cooling reserve while doing a fine job of keeping temps stable and humidity down.

There is also the thought that while Ebaugh's system MAY be perfectly balanced in size to run 100% of the time as in your statement, it could also be slightly undersized. Or not working 100% too. All three would lead to the same end result with a unit that works 100% of the time.

 

[aronhk_md]

I totally agree that do-it-yourselfers result is a lot of serious hack jobs. Household and boat electrical systems are a prime example. But with new technology like LFP, you get some pretty smart people, often times trained professional engineers in their real life, leading the way to figure out how to apply new technology in a new way. We should encourage them.

Definitely true that there are a lot of amateur hack jobs in the boating world. Someone decides they want SOMETHING on their boat, and d*mn if they are going to go buy that expensive panel, switch, or whatever at a marine store and pay big $! "H*ll, I can do that myself!"

I really think less of that occurs as the $$$ amount of the projected add on increases. How many hack jobs occur on a $60,000 repower? skidgear is right in one respect. The lower the price tag the more likely someone will come along and do a half *ss job throwing it in.

But this upgrade is one that's not easy to engineer, and also not proven to save $ as of yet over other ways to power a boat, and still not cheap. Therefore the people trying it are what I refer to as "thinkers". They may not do things the ideal way on the 1st, 2nd or even 3rd try. But they are also not usually hackers. And I'm perfectly happy to have one as a neighbor in my marina even knowing there is the possibility something could go wrong.

I'll worry more when there is a whole cheapie solar array available at Harbor Freight capable of powering your entire boat for $1500 and it fits in one of their shopping carts. At that point you'll have guys in your marina who were looking at their Harbor Freight sales flyer last night and said...

"H*ll, I can do that myself!"

 

[Phil Fill]

I installed 4 dirt window units on the Eagle, 3 – 6000 BTU and one 8,000 BTU which takes between 40 to 50 amps, and some time blow the breaker. I do not want raw water circulating through the boat. The three 6000 are in the staterooms, and the 8,000 is in the salon. I made wood enclosure for the units to fit/slide into and butted up against a port hole and a salon window. Since there are 4 units we can adjust each unit. In the winter when the ports and window are closed we use them on fan to clean/circulate the air. So we use them year around.

When away from the dock we have either the main gen, 10 kw or the cruise gen 5 kw running of the main 671. I would not even attempt to run AC off the inverter and house batteries. My feeling is batteries and inverters are for small boat in the warmer climates.

 

[Underway]

skidgear - you are assuming a lot just because the batteries in a pack "bulge". All materials expand and contract with temperature changes including the concrete on a sidewalk, metal sections on a road surface and the list goes on...and it does not take huge temperature changes to do it.



You knock "internet experts", but many times some of those people know more than the organizations you seem fond of. Same thing happens in medicine. I have seen patients and parents of patients who have researched an illness or topic so extensively their knowledge surpasses that of most physicians who are "experts" in their field.

If you think this is the rare occurrence, think again.

Often times regulatory agencies have relatively inexperienced and poorly informed people making decisions. Even where experience and knowledge are adequate generally speaking, they aren't necessarily cutting edge. And then there is the FACT that many times regulations and guidelines are placed solely to benefit whomever had deep enough pockets to lobby and place them.

If your worry is the boater in your marina who managed to piece together a "cutting edge" solar array and battery bank, then nothing anyone can say here is going to make your nights less restless.

I personally am less worried about that sharp thinker than I am about the droves of beer drinking yahoos that know what a throttle is and have a wallet capable of paying for a boat. And those holes in the water come in all sizes, not just runabouts/jetskis.

I'll take the thinker/tinkerer any day as a neighbor in the slip next to me. Yes, without regulation forcing his hand. As for the beauty contest you are referring to...maybe you think there needs to be guidelines regarding aesthetics of a vessel too? Or perhaps regulations?

"buy used up packs and pick out the "good cells"...really? Does every yahoo understand how to do that safely? Are the cowboys going to carry around a sign on their boat that says they're stupid? Who defines what a minimum safe system should look like....the average of opinions from wild eyed enthusiasts on internet forums? It's not just about you. You bet I have a concern about the uninformed. Again, if they keep their kluge at anchor out in the middle of the harbor, please have at it."

I go back to some statements about other potential areas we should maybe regulate so you can sleep soundly at night. I think considering your concern for safety we should DEFINITELY regulate the usage and sale of used tires for the vehicles we drive. After all, they are 2 plus ton vehicles hurtling down our roads often times in opposite direction to the vehicle you are driving, separated by a little white or yellow line and at closing speeds often in excess of 130 mph.

Think of those millions of craigslist ads for used tires while you head down the road toward the marina, where deckofficer has his awfully dangerous boat berthed next to yours. Who checked those used tires and made sure they were safe to be put back on the road???!!! Just curious if you have a crusade for safety there too?

Just one of a zillion potential hazards we live with that someone with a crusade could point to logically as a serious threat to life, and limb. An area that could really use regulation, forget guidelines! Inspection lanes passing a car through every few years as we have in many states are not nearly sufficient to eliminate/reduce the danger. They weren't really designed to.

Dangers exist in your own home, before you ever decide to open the door and step outside. And yes, some of them should be regulated. But it is impossible to eliminate them all, and ridiculous to try.

Regulation in this country has gone way beyond anything sane. Its time to triage the "patient" and stop the hemorrhaging before it dies.

And once again the thread goes off course, and I am partly to blame.



Ebaugh - 2 things

1) The drain you are talking about running twin 16,000 BTU units, one at 100% during the day is far greater than what I need. I am quite happy to zone the A/C and live in one are of the boat primarily at a time. If I want to head into the stateroom I'll turn on the A/C for a few minutes ahead and use a fan till it cools. I know this boat was comfortable with a 12,500 and 8,000 unit from the prev owner.

I am surprised though to hear that your A/C unit runs at 100%, never cycling the compressor off. It sounds as if that unit isn't sized right for the area it is cooling or it isn't working correctly?

2) I factored in plenty of "cloud" time when figuring out the cost of running a gen set. But I also have to factor in the absolute need to use the generator to a degree even if using solar for most needs, and I really didn't do that. Lets say you get a week of cloudy weather, but its still hot and sticky as hell. Going to want to run the A/C.

But hopefully during those times the A/C isn't under the same heavy load too. Still its an expense I hadn't added into the solar side......and need to. lol

--------------------------------------------------

Another item I plan to have on the boat is a misting system on the upper deck. I wanted it just because I love them around the pool...why not have them here too? But it didn't occur to me until some of the posts here that they could potentially keep the cabin cooler when inside. Interesting thought.

Another 2 factors that may work in my favor, and not everyone has this advantage...A) my upper deck is completely shaded. The sun will still shine in once it begins dropping toward the horizon, but the worst hours of the day I'm well shielded. B) The boat is all aluminum. The white cabin sides will stay cooler than fiberglass, and much of the hull will act as a heatsink using the water it contacts. The opposite holds true in winter, but I have another plan for heat besides electric.

Solar as a dollar wise smart main power source is still a "what if" scenario until I know much more though. Enjoyable to discuss it certainly is. lol Meantime I am looking at equipment out there, what things do, and why.

Please. The poster said they bulge when pushed exceptionally hard. Why, how, what happens inside, what happens next, what allows them to be pushed beyond normal operation, what sort of supervisory equipment is missing to allow it to happen.

I didn't say I have a concern with someone who does it right. The problem is I can't tell the good guys from the bad guys. The lithium police will be taking care of that.

Yes, I am absolutely in favor of legislating against ugly boats.

Regarding lithium batteries, I have already said I'm for guidelines and education....so should you. I have specifically stated that I am not a proponent of regulation....you might want to read what I said.

Regarding your diversion into tires and the automotive world....I am more concerned about kit cars that use the front tie rod as a bumper. Collision with a chipmunk would put these vehicles out of control.

I assure you I know more about regulation and guidelines than you can imagine. In any case there's this thing called engineering analysis. And the engineers use this process called failure modes and effects analysis. And by golly it's in writing and it's public. I want to see this from the manufacturers and/or from a professional organization like ABYC. If it has to come via the insurance companies, I could care less. Simple. You'll like it.

Regards

PS I hope you will refrain from running your misting system if you're parked next to my boat.

 

[Underway]

All the innovation and engineering comes from the industry, and they need to demonstrate to and convince the FAA that their designs are sound. Usually it works. I think it's naive to even consider that the FAA figures out how to apply new technologies.

I totally agree that do-it-yourselfers result is a lot of serious hack jobs. Household and boat electrical systems are a prime example. But with new technology like LFP, you get some pretty smart people, often times trained professional engineers in their real life, leading the way to figure out how to apply new technology in a new way. We should encourage them.

Organizations like ABYC, whom, buy the way, I'm very much in support of, come in at a later time in the life cycle. At least that's how I see it. Their role is to be sure there are good guidelines for mass deployment where the people doing the work won't be as knowledgeable as the pioneers. Standards help ensure consistent application of best practices.

For most people, waiting for LFP to be considered and reflected in ABYC standards before using the technology is likely a good approach. But I also think it's great that TF and Cruisers Forum can bring together the pioneers for this application and help accelerate the overall adoption.

I didn't say the government figures out how to apply new technologies. But they do establish safety standards and guidelines....in conjunction with manufacturer's, users, and the public at large. To do that, they do their best to understand the technology. Been there, done that.

I'd guess that every single one of the hackers out there view themselves as pioneers. Now there's a scary thought. We should encourage the real engineers out there to contact ABYC and get some formalized guidelines on the street ASAP. Put the effort into getting the technology introduced correctly. Contact ABYC and tell them to get after it. By the way, I dislike the ABYC/surveyor/insurance cabal intensely when it comes to applying new standards to already approved systems in old boats. But new technology applied to old boats is precisely where their expertise should be applied.

 

[aronhk_md]

Please. The poster said they bulge when pushed exceptionally hard. Why, how, what happens inside, what happens next, what allows them to be pushed beyond normal operation, what sort of supervisory equipment is missing to allow it to happen.

I'll repeat, everything expands when it warms up.

What happens when your 2 Liter soda bottle warms up? Why, how, what happens inside, what happens next, what allows the plastic of the bottle to be pushed beyond normal operation, what sort of supervisory equipment is missing to allow it to happen?

You can ask the same questions about anything that expands when the temp goes up, and that's every bit of matter that exists. I'll repeat, everything expands when it warms up.

But you are assuming because of experiences within the lithium battery field that 2 dissimilar battery types are similar in some fashion because they contain lithium. Its an assumption only and based on no scientific evidence, yet you use terms such as "engineering analysis" freely. You are also assuming that this expansion may in some way be related to the fire hazard some lithium cells have posed. Again, nothing more than an assumption.

Do you have knowledge here or are you just using word association? If you have knowledge about these batteries indicating their safety under load, please share it. "Please. The poster said they bulge when pushed exceptionally hard." and what followed is not a scientific analysis of anything. Nor is it a reference to any other expert's knowledge on the matter.

I didn't say I have a concern with someone who does it right. The problem is I can't tell the good guys from the bad guys. The lithium police will be taking care of that.

I'm saying we don't need "lithium police".

Yes, I am absolutely in favor of legislating against ugly boats.

Good luck with that.

Regarding lithium batteries, I have already said I'm for guidelines and education....so should you. I have specifically stated that I am not a proponent of regulation....you might want to read what I said.

I know what you said, but I feel differently. I feel you are a proponent of regulation regardless of what you said.

Regarding your diversion into tires and the automotive world....I am more concerned about kit cars that use the front tie rod as a bumper. Collision with a chipmunk would put these vehicles out of control.

I think you totally miss my point with that analogy, not diversion. But your response is interesting.

1) It was to point out a very real danger that you face daily...in fact many times a day as hundreds of cars pass you, and compare it with a theoretical one that you MIGHT face someday. Yet your crusade is aimed at this threat that you visualize, but may not even exist? I think Don Quixote had a similar crusade. Seems to me there are better uses of time, including the time you spent discussing this with insurance companies.

2) I sit here at a loss for words regarding the kit car statement. You'll pass thousands of cars all year long, some of which may be riding on tires that could pose a threat to you or family if one disintegrated in proximity to your vehicle at speed...but you'll worry that IF the one kit car you MIGHT pass yearly should HAPPEN to hit something with that tie rod while in your vicinity...something bad might happen?

I'm blown away.

I assure you I know more about regulation and guidelines than you can imagine. In any case there's this thing called engineering analysis. And the engineers use this process called failure modes and effects analysis. And by golly it's in writing and it's public. I want to see this from the manufacturers and/or from a professional organization like ABYC. If it has to come via the insurance companies, I could care less. Simple. You'll like it.

There is also this thing called a scientific study, which is used in a good analysis, engineering or otherwise, and I have a LOT of experience and knowledge about the way scientific studies are set up and interpreted. A well designed study can often show you the results you aimed for in setting up the study, and drug companies use this to their advantage quite often. Ever wonder why one medical study supports a theory and another medical study on the same subject matter seems to be 180 degrees in opposition to the first? Often because though the studies were on the same matter, they were set up differently.

So the fact that its in writing and public is important? Yes, we live in a "free" country...its all public unless its proprietary property. I don't think anyone is attempting to hide anything here. I'm not arguing that you know something about regulations or guidelines. I'm arguing the lack of need for them in many circumstances. Yet we get them shoved down our throats everywhere we turn, whether needed or not. Billions of $s wasted on studies and committees evaluating the most useless things.

"If it has to come via the insurance companies, I could care less. Simple. You'll like it."

You may not care, but I do and I doubt I'll like it.

PS I hope you will refrain from running your misting system if you're parked next to my boat.

I wont refrain from using my mister. I will however do all I can to make sure its not getting your boat wet. Most of the time its the few feet surrounding the people using it. I prefer a light mist, enough to feel good on the skin, but not enough to soak the surrounding area. Kind of hard to enjoy drinks, a snack or a good book if everything is wringing wet. Also its a waste to point the nozzles at someone else's boat. And if the wind is such that its really carrying across to your boat I'll do the polite thing and turn it off.

 

[Underway]

YAWN.

....and if the wind is such that its really carrying across to your boat I'll do the polite thing and turn it off.

Very kind of you.

 

[aronhk_md]

When away from the dock we have either the main gen, 10 kw or the cruise gen 5 kw running of the main 671. I would not even attempt to run AC off the inverter and house batteries. My feeling is batteries and inverters are for small boat in the warmer climates.

Hey Phil, no argument on the A/C units, use what works for ya . I don't think I'd have enough room to walk around my decks comfortably with the A/C units protruding from the windows. The decks are only 24" wide, which is quite comfortable if there is nothing sticking out.

I also like the marine reverse cycle air because its taking water that is usually 70 something degrees at max and usually less and using it as the heat sink to cool the refrigerant. On a regular window A/C unit the aluminum fins are out in the 90 degree heat doing the same job, so it takes more energy to produce each BTU.

But I think it may be possible now for the first time to have a solar setup that will do the job if you are willing to just air condition the zone you are in, MAYBE for a price that equals what someone would spend on fossil fuels, or even at a savings perhaps! There are several people doing it, and I think their numbers will increase.

 

[deckofficer]

I should have never said anything about cell bulging. Again this only occurs when you surpass the C rate for discharge and charge. A lead acid battery is rated at 0.05 C discharge and 0.1 C charge. If you go over 0.05 C discharge the LA will not give its rated capacity and if you go over 0.1 C charge it will gas.

A LiFePO4 cell without banding is rated at 3.0 C charge and discharge, higher with banding.

To put this in perspective, lets used Reuben's LiFePO4 48 volt 1000 a-hr bank. Since it is LiFePO4, acceptable charge and discharge rates are 3000 amps or 156,000 watts, which is a lot. If he used LA for a 48 volt 1000 a-hr bank, then discharge would be 50 amps (could go higher but would not retain advertised capacity) or 2400 watts, and on charge you must stay within a 0.1 C charge rate or 100 a-hr, or 5000 watts.

With the hydrogen gas given off from an LA under charge (and huge amounts if you charge over 0.1 C), I'll take the safety of LiFePO4 any day.

 

[aronhk_md]

Thanks deckofficer. I often have to slow down to understand the electrical stuff, or read it through a few times. The LiFePO4 cells certainly seem very capable. For someone like me, thinking about the idea of using solar, it makes sense to double, triple quadruple check myself doing calculations AND researching the requirements and needs of such a system. It would be folly to use one source, especially a forum, as the gospel in making decisions.

But this is an EXCELLENT source to share ideas and bounce questions around. These ideas can become the basis of research. It is also a wonderful place to share important finds...like when someplace has batteries on sale, or anything else.

Listening to the experience of others can help avoid pitfalls for those following their footsteps. I for one am grateful for men like you who are willing to try, perhaps fail, dust yourself off and try again. I served with army special forces, and that spirit is appreciated It is often why some succeed while others fail. I appreciate your willingness to share your knowledge too.

Thanks to all who responded to my post. I may not agree with skidgear, but even within that conversation there may be things that set others to thinking, and that is always a good end result. I know it had me thinking.

 

[RickB]

I'll repeat, everything expands when it warms up.

Except ice.

 

[deckofficer]

aronhk_md, my pleasure. I would have switched to LiFePO4 for the EVs (electric vehicles) when they first came out, but until last year they were too expensive for me. The small pack I assembled for my kayak and remote work away from the mains have shown how conservative these cells are rated. I have an electric chain saw with a 1800 watt motor that would lose a lot of power just going through a 100' 12 ga extension cord. Plugged into an inverter on just one of my packs it has plenty of power and will run longer than I have the energy to run it. On the kayak, my range has gone from 16 nm to 80 nm on the LiFePO4 cells. For my future house/propulsion bank it will probably be (16) of the 700 a-hr cells in series for a 48 volt (52 volt nominal) bank that will be the last bank needed for my time left on this earth. And yes, it will power an electric galley, BBQ, and A/C, and be charged by about 2000 watts of solar. I do enjoy a quiet anchorage.

 

[aronhk_md]

lol Rick, I should have stated that it does not always hold true when matter changes state. For example, solid to liquid. But it IS true enough in most circumstances that a "bulge" as something warms in temperature is not in and of itself synonymous with hazard

deckofficer - I look forward to hearing more about your projects as they progress.

Thanks folks!

 

[RickB]

It doesn't have to change state ... it shrinks as it rises from 0 to 4*C, above that it starts to swell - I first wanted to write "except for cold water" but thought that was picking too fine a nit for literary impact.

 

[FF]

I have an electric chain saw with a 1800 watt motor that would lose a lot of power just going through a 100' 12 ga extension cord.

Next time spend the extra bucks for a a tool with a universal motor.

These are the ones with brushes , that are replaceable , the brush caps are visible.

Use under voltage to operate the usual AC motor and the amperage required actually rises as the voltage drops. 1800W is 1800W weather at 120V or 90v. Big change in amperage draw tho.

The universal motor simply acts as if it were built as a 90V motor , no amp rise , but an output power drop proportional to the voltage supplied.

Universal motors are more expensive , but many can be found at tag sales , our 1960's Porter Cable 18inch is happy to operate on 400 ft of #12 extension cord.

 

[Underway]

Material from the very recent NTSB forum on lithium batteries. Many questions still remain...that per the experts. ABYC and the pleasure boating industry need to be in this loop (and they have been so advised).

Forum: Lithium Ion Batteries in Transportation

 

[deckofficer]

FF,

If the motor will do 1800 watts of work at 120 or 90 volts, then the current will need to compensate. At 120 volts it would require 15 amps, at 90 volts 16.7 amps. Your house plug will see 1800 watts at either voltage in this case, but that 1800 watts is shared by the motor and the lost wattage in heat along the 400' extension cord run, so there will be a power drop.

 

[twistedtree]

I've gotten so lost at this point in this thread. Did I ask what the failure modes actually are for LFP batteries? I though I did, but maybe it was in another meandering thread.

Does anyone what the actual failure modes are? What are we actually protecting against with LFP?

 

[aronhk_md]

skidgear - yes, many questions remain. Its still relatively new technology, and it can be dangerous. We certainly know a bit more about gasoline and how to handle/use/transport it. I am still not in fear of deckofficer and his home assembled lithium battery storage though. Or anyone else. I have yet to hear, "Mom sets house on fire with home assembled lithium battery bank".

I believe there are more pressing concerns than guidelines or regulations at this point for DIY boaters. Most guidelines and regulations will most likely be aimed at the manufacturers of products for use in the field for now. Until they exist, and even after it pays to be careful in your approach. And of course there may eventually be guidelines or regs that we need to adhere to. Most likely it will be because Joe Blow urinated on his cell pack after a night partying on board.

But Joe Blow doesn't have a case of beer under one arm and solar array components under the other as he's walking down the dock to his boat. Yet.

When Harbor Freight begins to offer a lithium based solar array for homes, cars and boats I might begin to worry about whether my neighbor has one.

Twisted - page 9 of this link was most succinct I believe.

http://www.ntsb.gov/news/events/2013/batteryforum/presentations/Doughty%20Sandia%20Presentation%20-%20Battery%20Forum.pdf

Original link courtesy of skidgear

 

[aronhk_md]

Rick - Yes you are correct about water. BUT, the changes occurring to expand water as you progress from 4 degrees Celsius down to 0 degrees Celsius ARE the changes occurring from change of state, liquid to solid. At any one time the energy level of molecules in a given mass of water varies. At 4* C some of the water molecules have aligned their H molecules with the neighboring molecules. This is a less dense state, and what happens to all the molecules by the time the mass reaches 0* C.

The change from liquid water to a gas also doesn't happen at once for all molecules in a given mass. Some molecules manage to obtain more energy than their neighbor and make the jump first.

But yes, I stand corrected about matter in general expanding as temp increases, though I meant it as a general statement to indicate that BULGING does not = BAD (wish I could draw a line through the equal sign here! lol).

 

[deckofficer]

In tests they have punctured the cells, overcharged to the point that expansion breaks the case open, and shorted the cells, and no fires in any of these cases. The only aspect that can cause a fire holds true with other batteries, and is the foreign object that has come in contact with the terminals could melt and cause a fire. The amount of amps a LiFePO4 cell can deliver when shorted is quite large, so don't drop your wrench across these cells. Here is a picture of a split second short of just one cell when I accidentally brushed this alligator clip on the terminals.
Notice the crater in the bolt's head and the vaporized piece of screw thread from the alligator clip. Amazing what 3.2 volts can do.

 

[Phil Fill]

Hey Phil, no argument on the A/C units, use what works for ya . I don't think I'd have enough room to walk around my decks comfortably with the A/C units protruding from the windows. The decks are only 24" wide, which is quite comfortable if there is nothing sticking out.

I also like the marine reverse cycle air because its taking water that is usually 70 something degrees at max and usually less and using it as the heat sink to cool the refrigerant. On a regular window A/C unit the aluminum fins are out in the 90 degree heat doing the same job, so it takes more energy to produce each BTU.

But I think it may be possible now for the first time to have a solar setup that will do the job if you are willing to just air condition the zone you are in, MAYBE for a price that equals what someone would spend on fossil fuels, or even at a savings perhaps! There are several people doing it, and I think their numbers will increase.

They are in inside the boat not on the decks as we have no side decks. Most of the time we have on fan and/or energy saving setting. In the summer I been leaving the plex a glass up and we close the thermal curtains to keep the sun and warm air out. We try to keep the cool morning air inside the boat so in the summer the boat the same as in winter. The roof is gloss white and silver tarp is laid on the dark teal deck, so the heat is reflected and not absorbed.

If we were in warmer climate, we would probably have solar and wind, but in the PNW they are not worth it. In the PNW wind gen would be better than solar as it blows most days even in the summer.

 

[RickB]

Rick - Yes you are correct about water. BUT, the changes occurring to expand water as you progress from 4 degrees Celsius down to 0 degrees Celsius ARE the changes occurring from change of state, liquid to solid. At any one time the energy level of molecules in a given mass of water varies. At 4* C some of the water molecules have aligned their H molecules with the neighboring molecules. This is a less dense state, and what happens to all the molecules by the time the mass reaches 0* C.

All the molecules may not be rearranged until around -40*C ... ever heard of or experienced "supercooled water droplets"?

Rather than look at water as freezing at 0*C it may be better to look at ice as melting at 0*C and liquid water between 0 and 4 as liquid water, not incipient ice.

 

[aronhk_md]

Rick - again you are correct. I hadn't actually heard the term, but just did a quick read. I understand the principles. I was going off long term memory from days long gone saying that all molecules changed state at 0, and that was apparently erroneous info to have stored. lol. Most likely I knew better at one point and my brain corrupted the info. Makes sense though. I always knew these changes were over a range and dependent on multiple factors.

I do realize that water between 0 and 4 is still water. Those molecules aligning their H's are not "frozen" that way. They are in a state of flux. Neat stuff water is...unique.

My thrust though was to point out that there need not be fear over a lithium pack bulging as its temp increases. Someone not aware of all the facts might read this thread and think, "OMG, he's right! (skidgear) The packs bulged!" and automatically think that is a bad sign and associate it with hazard. Does the bulging have meaning? Sure. I just wanted to make sure that readers had some context so they can find the answers to that meaning as I did.

 

[RickB]

No problem, it was just a fun exchange that unless you are flying around in cumulus clouds doesn't (pun intended) impact most people.

 

[aronhk_md]

Its a great exchange. A little off topic, but I love learning. Whether I try solar as a main power source right now is still up in the air as I continue to research it, but its exciting to me that it may finally be possible and financially feasible.

I have a couple of muscle cars, one that is a quiet (relatively) and comfortable ride, but makes 1200 hp using a turbo on pump gas. But they are fun vehicles I use here and there. Not as regular transportation. For many years I drove a little beat up Toyota tercel as my main vehicle because with almost 40 mpg it just didn't make sense to go get something else since it ran perfectly. I put brakes, tires and one sensor on it in 130,000 miles.

But truthfully I hate the idea of my $s going overseas for fossil fuels, and of course there is the pollution of our world to think of. Every time I open a package of something I think about the waste, and where it is going. And yes, I know I bought a boat that isn't fuel efficient, but like the muscle cars I don't plan to take it everywhere. I may someday repower her with something better. Electric propulsion is still a pipe dream, but who knows...someday...

 

[twistedtree]

Twisted - page 9 of this link was most succinct I believe.

http://www.ntsb.gov/news/events/201...ughty Sandia Presentation - Battery Forum.pdf

Original link courtesy of skidgear

But all the NTSB stuff, including the above paper, is about Li-ion, not LFP. If I understand much of what this thread talks about, these chemistries have little in common other than the use of Li. I thought we shouldn't be comparing them, and that doing so was a large source of confusion on this subject? Or am I just confused? It surely wouldn't be the first time.