Oceanvolt Hybrid Motor

[BigBeakie]

Originally Posted by 44'cruisingcat

So where on the data sheet do the batteries state how much they "like to work"?

Yeah, I figured you'd come back with yet another low value response. No information. just more of the same, snide comments and flapping gums, or whatever the internet forum equivalent is.

Life is too short to bother listening to you, especially about matters EP.

Actually, I think it was either Mainsail or Rich Boren (might have been someone else on CF, can't recall) who used that expression re LFP battery characteristic. Since you don't seem to have even a modest ability to read and interpret a phrase, I'll spell it out for you. It means that LFP have the ability to be discharged deeply and recharged over many cycles without losing much C capacity like Lead acid batteries do. Likewise, their lifespan is not as affected either, and they can be discharged deeply ( to 80% to be specific for you pedants) and still have thousands of charging cycles. In the case of the Valence, over 4,000 cycles at 80% DoD. You will notice I never said that the lifespan was NOT affected, but my expression was meant to imply that they are relatively, re lead acid batteries, more long lived over many more cycles.

So 44C, You have built a gorgeous boat, you understand how to sail it up and down the coast, and you are knowledgeable about some aspects of multihulls. About EP however, you are clueless, and IMHO, not to be taken seriously in this discussion.

[44'cruisingcat]

Just FYI, I've been running lithium ferrophosphate batteries for the last 2 years. So I actually do know a little about them. How long have you been using them for?

Fact is, they CAN be cycled more deeply than lead acid batteries, significantly so, but the fact still remains, they'll last longer if used through shallower cycles. And the difference can be very significant. Like many years longer life.

As to your question, "who cares?", well really, you should. If you're replacing several thousands of dollars worth of batteries far more frequently due to them being used as part of your propulsion system, then that's a significant addition to your running cost, as well as a significant environmental impact. Isn't part of the point being more "green"?

[44'cruisingcat]

It's always entertaining to see which side of this discussion is first to fail to argue facts, and resort to insults.

And it's always the same side.

[BigBeakie]

Originally Posted by 44'cruisingcat

Just FYI, I've been running lithium ferrophosphate batteries for the last 2 years. So I actually do know a little about them. How long have you been using them for?

Fact is, they CAN be cycled more deeply than lead acid batteries, significantly so, but the fact still remains, they'll last longer if used through shallower cycles. And the difference can be very significant. Like many years longer life.

As to your question, "who cares?", well really, you should. If you're replacing several thousands of dollars worth of batteries far more frequently due to them being used as part of your propulsion system, then that's a significant addition to your running cost, as well as a significant environmental impact. Isn't part of the point being more "green"?

Well, goodie for you. I and a friend have had a test bench LFP running on charge discharge for over 3 years, and then he got bored waiting for it to crash, which it never did, and he gave it to a caravan friend. So we know something about the DoD expectations of LFP.

So, how often do you run a discharge/charge cycle? A couple times a week, maybe? How far down do you take your battery? I guess about 50% from what you are saying?

Now I'll give you some data from the Valence tech labs, chart attached.

At 80% DoD they get about 4,500 cycles. At 1 discharge/charge cycle per day, that's 365 cycles per year, they WARRANTY that you can expect 4,500/365 days = 12.328767 YEARS of use. Since you are a pedant, I thought I should include the significant digits, for precision.
If you cycle them twice a week, you'd expect 4,500/2 per week = 2,250 weeks/52 weeks per year = 43.26923 years of useful life.

But apparently that's not enough for you, so what happens if you only take them down to 50% DoD, as you seem to do? Then from their chart you get 10,000 cycles. Oh my, yes, that's MUCH better!

10,000 cycles/ 365 discharge-charge cycles per year = 27.39726 years. You know what 44C? By gosh you were right! That's much better, isn't it? It's over DOUBLE the lifespan Sure are saving money now, aren't we? Oh, and if we only cycle them twice a week, why that's 10,000 cycles/2 per week= 5,000 discharge cycles/52 weeks per year =96.153846 years!

So you were definitely right 44C, you will be able to have not only your children still using your same batteries, you can pass your boat onto your grandchildren, with the same batteries!

Thank you so much for pointing out my folly to me, much appreciated

[transmitterdan]

There is a lot of data that suggest no LiPoFe batteries will last 25 years. It's not just a question of how many charge/discharge cycles they can do. It's also a question of how long they can survive fully charged. You can increase life by not fully charging. But if fully charged after every deep discharge then I guess they will last something on the order of 5-10 years. And if you have a lot of parallel batteries in a big bank the odds are one will fail before the others. Then you have to decide how to deal with the replacement. It isn't credible to claim a battery bank will last 27 years since all known data says they will not.

[44'cruisingcat]

He's in senseless rant mode. There's no point trying to talk sense.

[BigBeakie]

Originally Posted by transmitterdan

There is a lot of data that suggest no LiPoFe batteries will last 25 years. It's not just a question of how many charge/discharge cycles they can do. It's also a question of how long they can survive fully charged. You can increase life by not fully charging. But if fully charged after every deep discharge then I guess they will last something on the order of 5-10 years. And if you have a lot of parallel batteries in a big bank the odds are one will fail before the others. Then you have to decide how to deal with the replacement. It isn't credible to claim a battery bank will last 27 years since all known data says they will not.

That was my point. Sorry it was too subtle.

[transmitterdan]

Sorry I could not deduce your point at all. Maybe try again with less personal animosity and explain what you are trying to get at.

[BigBeakie]

Originally Posted by transmitterdan

Sorry I could not deduce your point at all. Maybe try again with less personal animosity and explain what you are trying to get at.

It's quite simple, really.

I stated that I was planning on taking the LiFeMnPo4 bank down to 70% to 80% DoD, because they "like to be worked". That phrase would be synonymous with "it doesn't do them any harm", "they can do that easily"," "there is no downside to", whatever phrase you want to substitute for "it is well within their design parameters to be able to deliver".

44C objected to me using the phrase "they like to be worked" , presumably because either he; (A) thought I was anthropomorphising batteries, not realising they are inanimate objects and can have no preferences, or, (B) he could not make the "thinking leap" of what I meant, or (C) he disagreed with discharging them down to 80% DoD because I would be shortening the lifecycle of the batteries.

I thought I made the case subsequently, if it was (C) above, that it is a case of "so what?" That is, even if you discharge down to 80% DoD, you still get many, many years of use from them, enough to cruise for AT LEAST, at a MINIMUM, a decade or more, at my proposed use case.

I made no statement at all about specifics of how I was intending to charge them, to what SOC, etc. I am well aware, having read the entire thread on LFP as a house bank thread, on the viewpoint that LFP should be charged to about 13.85V, below the upper knee, in order to prolong their lifespan.

I am trying to share what I have learned, and what I continue to learn, about OceanVolt EP with the CF community, because I know that at least some are genuinely interested in the topic. Others are not, and that is fine by me. If they have something meaningful to contribute, then by all means, show us your evidence based data. I have yet to hear any data that contravenes what has been shown to be reality, with the Kato example, for example.

It's perhaps got to a point where maybe a "put up (data) or shut up" would be of more benefit to those seeking real information, rather than unsubstantiated opinion, snide adolescent comments, deliberate obfuscation and misconstruing what has been said.

I know of some who could well take part in this discussion and contribute substantially, but when they read the purile, denialist type of opinions, it puts them right off. So, IMO, that is not a good result.

[transmitterdan]

I don’t think I am a purile denialist. I have some experience engineering systems. What makes people like me a bit disenchanted with the proponents of EP is when claims are made that are not in engineering units. “like to be worked” isn’t an engineering term so it will catch some flack from certain corners. If “worked” means charging to 100% as fast as possible and then discharge to 20% SOC in a few hours then I doubt any battery will last 10 years doing that every day. They are spending over 50% of their life fully charged. That is a significant drag on lifetime. If “worked” means charging to 80% SOC and then discharging to 20% then the expected lifetime goes way up. But I consider that scenario to be less worked. And also uses only 75% of the capacity compared to the aforementioned “worked” case.
I think the field data suggests that these batteries do not “like to be worked”. They like to be babied using only 60% of their rated kWH capacity.

If there is someone out there with engineering data that shows EV is right for a lot of cruisers in terms of performance, capital cost and opex why would anyone here belittle that person. Quite the opposite, we would be really glad to understand the data. What we have up to now is data that says one has to compromise something that is not compromised with mechanical diesel power. That’s ok as long as one knows and can live with the compromises. All aspects of boat design require compromises. But it seems the EV proponents get cranked up when the compromises are mentioned. Then strange equivalences start coming out and we devolve into meaningless marketing speak. I am not interested in opinions. I am interested in engineering facts.

BTW, denialist is a pejorative term. Purile as well IMO.

[BigBeakie]

Originally Posted by transmitterdan

I don’t think I am a purile denialist. I have some experience engineering systems. What makes people like me a bit disenchanted with the proponents of EP is when claims are made that are not in engineering units. “like to be worked” isn’t an engineering term so it will catch some flack from certain corners. If “worked” means charging to 100% as fast as possible and then discharge to 20% SOC in a few hours then I doubt any battery will last 10 years doing that every day. They are spending over 50% of their life fully charged. That is a significant drag on lifetime. If “worked” means charging to 80% SOC and then discharging to 20% then the expected lifetime goes way up. But I consider that scenario to be less worked. And also uses only 75% of the capacity compared to the aforementioned “worked” case.
I think the field data suggests that these batteries do not “like to be worked”. They like to be babied using only 60% of their rated kWH capacity.

If there is someone out there with engineering data that shows EV is right for a lot of cruisers in terms of performance, capital cost and opex why would anyone here belittle that person. Quite the opposite, we would be really glad to understand the data. What we have up to now is data that says one has to compromise something that is not compromised with mechanical diesel power. That’s ok as long as one knows and can live with the compromises. All aspects of boat design require compromises. But it seems the EV proponents get cranked up when the compromises are mentioned. Then strange equivalences start coming out and we devolve into meaningless marketing speak. I am not interested in opinions. I am interested in engineering facts.

BTW, denialist is a pejorative term. Purile as well IMO.

I do not think you either of those either, and my comments were not directed towards you. Your comments in this thread, from the very beginning, have been very rational.

My comments on EP are not from an engineers viewpoint or expertise, because I'm not an engineer. That are from the perspective of a potential user of EP for cruising. But, I can research, ask questions, sift out marketing BS, as well as the next guy.

Re the battery performance, charging voltage, SOC etc. I have received information from the manufacturer on these issues, including charging to a higher voltage than 13.85V, and am satisfied that they know the issues, and know what they are talking about.

Re suitability of a good EP solution for cruising, let's briefly summarise what has been shown with OV systems in operation and validated by owners:

1. An OV motor can propel a performance cruising catamaran at close to, i.e. within one or two knots, the same top speed as a diesel engine about twice the kW rating. Not at exactly the SAME top speed, but close.
2. The OV motors can deliver reasonable cruising speeds, i.e. 6 to 7 knots, for these cats using 7 to 8 kW of battery from suitable C rated LFP batteries, and this can be continuous motoring if a suitable genset is used to deliver the 7 to 8 kW needed.
3. For most motoring needs less than about 1 hour at top speed, or several hours at less than top speed, solar charging of the LFP bank would provide most of the energy required, until the next motoring event is repeated. Over a longer timeframe of cruising, solar can provide almost all the fuel required. The opex of this fact is a compromise that cruisers with diesel engines need to accept, and pay for, over and over again.
4. OV Servoprop regeneration is capable, at typical sailing speeds of these cats, to provide as much charging as a medium size genset, without slowing down the cat significantly, i.e. more than 1 knot.

So, to me, it appears the compromise, singular, you have to live with re EP is motoring at a slightly lower top speed for MUCH less time than running on diesel engines at WOT. If that is the major compromise of EP, I'm certainly willing to accept that compromise.

Lastly, denialist was not used as a perjorative, but as a statement of fact. I admit puerile was used for it's emotive effect, but IMO was justified for the individuals I had in mind.

[44'cruisingcat]

How much solar will you have, and what loads,apart from propulsion? For instance, is the galley going to be all electric? Is the hot water going to be powered by electricity from the solar panels?

[44'cruisingcat]

Originally Posted by BigBeakie

Well, goodie for you. I and a friend have had a test bench LFP running on charge discharge for over 3 years, and then he got bored waiting for it to crash, which it never did, and he gave it to a caravan friend. So we know something about the DoD expectations of LFP.

So, how often do you run a discharge/charge cycle? A couple times a week, maybe? How far down do you take your battery? I guess about 50% from what you are saying?

Now I'll give you some data from the Valence tech labs, chart attached.

At 80% DoD they get about 4,500 cycles. At 1 discharge/charge cycle per day, that's 365 cycles per year, they WARRANTY that you can expect 4,500/365 days = 12.328767 YEARS of use. Since you are a pedant, I thought I should include the significant digits, for precision.
If you cycle them twice a week, you'd expect 4,500/2 per week = 2,250 weeks/52 weeks per year = 43.26923 years of useful life.

But apparently that's not enough for you, so what happens if you only take them down to 50% DoD, as you seem to do? Then from their chart you get 10,000 cycles. Oh my, yes, that's MUCH better!

10,000 cycles/ 365 discharge-charge cycles per year = 27.39726 years. You know what 44C? By gosh you were right! That's much better, isn't it? It's over DOUBLE the lifespan Sure are saving money now, aren't we? Oh, and if we only cycle them twice a week, why that's 10,000 cycles/2 per week= 5,000 discharge cycles/52 weeks per year =96.153846 years!

So you were definitely right 44C, you will be able to have not only your children still using your same batteries, you can pass your boat onto your grandchildren, with the same batteries!

Thank you so much for pointing out my folly to me, much appreciated

Cutting through the drivel, the fact remains that you are going to have a battery bank about 4 times as big (and expensive) as a similar diesel boat would have, and you'll probably need to replace them more often. That's a significant operating cost that a sensible person would be needing to consider. IMO.

[transmitterdan]

Here are some of the compromises from my point of view:

1) inability to power the boat for hours or days into a strong headwind and big waves. The cost and weight needed to equip an EP boat with this capability is prohibitive at this time. Thus requiring crew to be overly paranoid about weather and avoid many lee shore anchorages. Anyway tropical weather prediction is an in exact science.

2) EP requires massive solar arrays well above a traditional boat. That adds weight and cost.

3) EP requires more fuel when fuel is needed to power the propellers. It's a simple mathematical fact that burning diesel to make electricity to turn an electric motor is less fuel efficient than plain old mechanical gears. The notion that electric HP is more powerful than diesel HP is silly.

4) reliability of an EP system is at least several times less than traditional diesel. I would guess it is about an order of magnitude less. Many thousands of diesels are running just fine after 30-40 years without any major repairs. I doubt any EP system can come close to that. Most diesels can survive a salt water flooding if recovered quickly. I have seen flooded engines and gears brought back to life in less than a day. No way EP can do that.

5) if water regen is part of the system then rigging and sails need to be able to generate significantly more power to drive the propellers. No matter how good the regen is it isn't >100% efficient. So the energy produced + wasted has to come from the rigging and sails. Significant regen requires significant power from sails. There is no free lunch.

It's up to each person to determine their own risk/reward equation. And EP has many rewards such as reducing emissions, quieter most of the time and plenty of electricity to make onboard life more comfortable. EP proponents don't have to come up with nonexistent features (e.g. easier maneuvering) to justify the decision to adopt. But I think it's better to just acknowledge the compromises than try to explain them away.

[DotDun]

Originally Posted by BigBeakie

I do not think you either of those either, and my comments were not directed towards you. Your comments in this thread, from the very beginning, have been very rational.

My comments on EP are not from an engineers viewpoint or expertise, because I'm not an engineer. That are from the perspective of a potential user of EP for cruising. But, I can research, ask questions, sift out marketing BS, as well as the next guy.

You've done nothing more than regurgitate the marketing BS by rearranging the words. It still lacks any technical explanation.

Originally Posted by BigBeakie

Re the battery performance, charging voltage, SOC etc. I have received information from the manufacturer on these issues, including charging to a higher voltage than 13.85V, and am satisfied that they know the issues, and know what they are talking about.

Re suitability of a good EP solution for cruising, let's briefly summarise what has been shown with OV systems in operation and validated by owners:

1. An OV motor can propel a performance cruising catamaran at close to, i.e. within one or two knots, the same top speed as a diesel engine about twice the kW rating. Not at exactly the SAME top speed, but close.

Your refusal to accept/admit how a diesel engine works doesn't exonerate this stupid statement. It's pure marketing.

Originally Posted by BigBeakie

2. The OV motors can deliver reasonable cruising speeds, i.e. 6 to 7 knots, for these cats using 7 to 8 kW of battery from suitable C rated LFP batteries, and this can be continuous motoring if a suitable genset is used to deliver the 7 to 8 kW needed.

I believe you are over estimating what 8kW total will do.

Originally Posted by BigBeakie

3. For most motoring needs less than about 1 hour at top speed, or several hours at less than top speed, solar charging of the LFP bank would provide most of the energy required, until the next motoring event is repeated. Over a longer timeframe of cruising, solar can provide almost all the fuel required. The opex of this fact is a compromise that cruisers with diesel engines need to accept, and pay for, over and over again.

Solar doesn't work at night, hopefully you don't need to do any overnight passages. And solar hardly ever delivers it's rated output, the different seasons wreak havoc with what solar delivers. You should plan for no more than 60% rated output in the winter.

As far as costs, you will pay far more in capex than a diesel sailboat will spend on fuel. And when you do power your boat from diesel, it will be far less efficient that a diesel driven boat.

Originally Posted by BigBeakie

4. OV Servoprop regeneration is capable, at typical sailing speeds of these cats, to provide as much charging as a medium size genset, without slowing down the cat significantly, i.e. more than 1 knot.

For a given amount of wind, you may be correct. But wind is variable. You'll need a lot of 'extra' wind, 5-10kts minimum more than required to move your boat, to produce any significant amount of regen power. Hence, if winds are light, you have to turn off regen so the boat will even move.

Originally Posted by BigBeakie

So, to me, it appears the compromise, singular, you have to live with re EP is motoring at a slightly lower top speed for MUCH less time than running on diesel engines at WOT. If that is the major compromise of EP, I'm certainly willing to accept that compromise.

WOT? Where is that coming from? When do you run engines at WOT?

Originally Posted by BigBeakie

Lastly, denialist was not used as a perjorative, but as a statement of fact. I admit puerile was used for it's emotive effect, but IMO was justified for the individuals I had in mind.

All IMO, or course!