Oceanvolt Hybrid Motor

[ssmoot]

Originally Posted by valhalla360

Even if we assume your 20hp is right (I think you are estimating low), that's still way more than 11hp or even kw which is the peak output with nothing left in reserve.

I pulled the 20hp number from Yanmar's spec sheet for that RPM.

Which matches pretty nicely with an Oceanvolt SD15.

It's probably not the system I'd have, but if cruising performance is your benchmark, these propulsion systems are pretty comparable. Sure you lose some efficiency with the generator filling the batteries driving the motor, but you also make free "fuel" assuming you've prioritized a large solar installation as well. Which IMO is a given if you're considering EP.

I'm not suggesting you'll be motoring continuously on solar. Just that I think it would more than make up for the inherent losses in the system (over time) compared to direct drive diesel propulsion. Single digit percentages sure. But enough to make the conversion losses a non-issue in the grand scheme.

Another, probably more important, thing to consider is that with a series hybrid and a giant battery bank, you'll be running your generator at it's most efficient RPM 100% of the time as well, regardless of where you put the throttle on your motors. Charge up to 80%. Run it down to 20%. Rinse, repeat. 18kWh at your disposal for motoring. More PHEV than EV in practice.

[valhalla360]

Originally Posted by ssmoot

The motor doesn't suffer from compression losses or significant friction losses as it ages (up until you need new bearings I suppose).

But I agree-ish. An old Perkins engine? I seriously doubt that's making rated horsepower. A modern Yanmar? I'd be surprised if its output varies much at all over it's serviceable lifetime. Modern Diesel trucks certainly don't have that issue AFAIK.

If we are talking about an old worn out diesel not putting out it's rated power...shouldn't we be comparing that to a similarly maintained electric drivetrain where the battery bank is getting weak and connections are corroded, maybe the controller is getting a bit wonky?

A comparable might be electric vs gas golf carts...I know several people struggling with electric golf cart issues (the motor itself is pretty reliable but the systems that feed power to the motor are usually the culprit)...this is not emerging technology and the choice is rarely based on avoiding petroleum products but on functionality.

[ssmoot]

Originally Posted by valhalla360

If we are talking about an old worn out diesel not putting out it's rated power...shouldn't we be comparing that to a similarly maintained electric drivetrain where the battery bank is getting weak and connections are corroded, maybe the controller is getting a bit wonky?

I don't think modern diesels would really suffer from that issue outside of neglect.

But fair enough. You'll definitely want to budget on replacing your ~$12,000 battery bank every 10 years I'd think.

Which would pay for a lot of diesel.

[valhalla360]

Originally Posted by ssmoot

I pulled the 20hp number from Yanmar's spec sheet for that RPM.

Which matches pretty nicely with an Oceanvolt SD15.

It's probably not the system I'd have, but if cruising performance is your benchmark, these propulsion systems are pretty comparable. Sure you lose some efficiency with the generator filling the batteries driving the motor, but you also make free "fuel" assuming you've prioritized a large solar installation as well. Which IMO is a given if you're considering EP.

I'm not suggesting you'll be motoring continuously on solar. Just that I think it would more than make up for the inherent losses in the system (over time) compared to direct drive diesel propulsion. Single digit percentages sure. But enough to make the conversion losses a non-issue in the grand scheme.

Another, probably more important, thing to consider is that with a series hybrid and a giant battery bank, you'll be running your generator at it's most efficient RPM 100% of the time as well, regardless of where you put the throttle on your motors. Charge up to 80%. Run it down to 20%. Rinse, repeat. 18kWh at your disposal for motoring. More PHEV than EV in practice.

Actually they aren't comparable because you need to run the 15kw electric at peak output for normal cruising to achieve the same output as the diesel...but that means you have no reserve power. If you want to size the diesel based on it's peak continuous output rating, you can but that won't be anything close to 1/4th the typical spec'd motors as implied by some.

If we take it at face value, you are not arguing in favor of EV but you are arguing the power plant (regadless of full source) can be smaller. That is a totally different discussion and depends greatly on the performance expectations under various conditions. If your propulsion goals are limited to getting in and out of the harbor (a couple miles range) a low HP motor (regardless of fuel source) using a big low pitch prop will do the job. But I would argue the typical cruiser buying a new boat has much higher expectations.

The funny thing is upsizing an electric motor incurs almost no efficiency loss (within reasonable limits) as long as you don't use that power and bigger motors don't cost much more...so it's really odd that they fight this simple solution.

Unless you get into massive solar arrays and don't use much for house loads...no you won't get any appreciable range from solar unless you accept drastically lower cruising speeds. Plus you have to factor in the cost to buy, install and maintain the larger system. It's a common misconception if you don't run the numbers.

As discussed, a properly sized diesel propulsion system is going to be at or very close to peak efficiency in most cruising situations, so the savings from a generator running at peak efficiency are going to be minimal at best and unlikely to overcome the losses related to multiple energy conversions. (this isn't a prius where you are selling tens of thousands of identical vehicles and you can justify teams of engineers squeaking the last 0.1% of efficiency out of the system.

[ssmoot]

Originally Posted by valhalla360

If we take it at face value, you are not arguing in favor of EV but you are arguing the power plant (regadless of full source) can be smaller.

Yes and no. Let's use the Helia Evolution as an example. You have a choice of Volvo D2-40 or D2-55. I guess. Looking at fuel consumption, the D2-55 seems to be a truly terrible engine. I'm going to use the D2-50 for reference instead.

The D2-40 makes about 28hp at 2,200 RPM and consumes 3L/hr.

The D2-50 makes about 30hp at 1,700 RPM and consumes 2L/hr.

And this isn't even the worst example I could come up with. Say you wanted 20hp for cruising.

The (45hp) 4JH45 will give it to you at 1,200 RPM and consumes 1L/hr.

So you only want 20hp. So you look for a 20hp engine right? Makes sense?

The 3YM20 will give it to you at 3,000 RPM, but it'll consume 3.3L/hr to do it!

So while I'd probably take the non-upgraded engine in most scenarios and get a D2-40 on my Helia and just throttle back a little and lose a half knot of boat speed, you can't realistically choose a diesel half the size without accepting that it'll burn 3X the fuel to make the same power as the bigger unit.

If I could get a 3YM20 that produced 20hp with 1L/hr, I probably would. I'd bank the price difference and weight savings (almost 500lbs for both engines!) and be a happy camper.

But that sort of option simply isn't available to you with a diesel. EP side-steps that issue.

So do I think the engines builders are putting in their boats are too big? Not really. Do I think peak power is a red-herring? Definitely. I don't think Fountaine Pajot is basing their engine sizing based on peak output, even if some consumers do.

Originally Posted by valhalla360

The funny thing is upsizing an electric motor incurs almost no efficiency loss (within reasonable limits) as long as you don't use that power and bigger motors don't cost much more...so it's really odd that they fight this simple solution.

Torqeedo does. Look at the specifications: 63kW (85hp) peak.

That's another overlooked thing. As long as you have good thermal management, it's no issue to overdrive the motor and double (or more) the power it's rated for continuously. All the EVs do it. You can't run a Bolt at the full 125kW continuously for example. That's it's peak rating. I'm not sure why Oceanvolt doesn't seem to do it. I suspect it's more to do with their choice in batteries. Torqeedo went for a high voltage EV based system. Oceanvolt uses more familiar drop-in replacement batteries I think?

Point is, you won't be getting 85hp out of a 4JH45 any time soon.

[valhalla360]

Originally Posted by ssmoot

Torqeedo does. Look at the specifications: 63kW (85hp) peak.

That's another overlooked thing. As long as you have good thermal management, it's no issue to overdrive the motor and double (or more) the power it's rated for continuously. All the EVs do it. You can't run a Bolt at the full 125kW continuously for example. That's it's peak rating. I'm not sure why Oceanvolt doesn't seem to do it. I suspect it's more to do with their choice in batteries. Torqeedo went for a high voltage EV based system. Oceanvolt uses more familiar drop-in replacement batteries I think?

Point is, you won't be getting 85hp out of a 4JH45 any time soon.

The link you provided...no where does it say you can over load the 40hp motor to get 85hp. You have to upgrade to the 80hp engine. It is a 66kw (80hp equivalent per toqueedo)....I would hope a 80hp motor can put out more than a 45hp motor.

It looks more like they electronically de-rate it for the low HP version as opposed to overloading the high HP version as they make no mention of overloading it.

Of course, it's not isolated to electric motors. It's common with diesel pickups to do this. For example, the latest F350 diesel is 440hp but if you buy an F550 (same engine) it's only rated fo 330hp.

While I doubt anyone bothered to jack up a little sailboat engine. I know guys chip diesel pickups and make other modifications to put out drastically increased power. It's not unusual to hear people talking about upping diesels to 500-700hp. I'm sure if you really had the desire and know how, you could rig up a turbo and some other mods to squeeze 80hp out of that engine.

I do question, if it really does put out 80hp peak...why do they call it "equivalent" HP. Historically the EV folks use that term to lie about the actual HP when the spec for peak HP is much lower. If they are calling out peak HP, either that's the peak HP or it's not...there is no "equivalent" needed, so why include it?

PS: I will admit at first glance it does look like the larger engine is significantly more efficient. but, you have to look at the actual torque/hp and fuel consumption. Just because an engine can produce a certain amount of toque/hp at a specific RPM doesn't mean that it is producing that amount (ie: if you goose the throttle to till the RPM matches the peak on the curve...the engine isn't producing anything close to peak HP as there is no torque). I'm betting if you dig into real world applications, there is something else going on...otherwise, no one would ever buy the smaller engine...who wouldn't want a more efficient more powerful engine that works under less load and presumably lasts longer.

[ssmoot]

Originally Posted by valhalla360

The link you provided...no where does it say you can over load the 40hp motor to get 85hp. You have to upgrade to the 80hp engine. It is a 66kw (80hp equivalent per toqueedo)....I would hope a 80hp motor can put out more than a 45hp motor.

You didn't look at the specifications. Look for "Input power (peak) in kW". 63.4 for the "40hp" version.

Originally Posted by valhalla360

It looks more like they electronically de-rate it for the low HP version as opposed to overloading the high HP version as they make no mention of overloading it.

Of course, it's not isolated to electric motors. It's common with diesel pickups to do this. For example, the latest F350 diesel is 440hp but if you buy an F550 (same engine) it's only rated fo 330hp.

While I doubt anyone bothered to jack up a little sailboat engine. I know guys chip diesel pickups and make other modifications to put out drastically increased power. It's not unusual to hear people talking about upping diesels to 500-700hp.

That's not really the same thing at all. They're mostly just raising boost pressure. There's no shortage of modified diesel trucks on YouTube blowing their head off.

Originally Posted by valhalla360

I do question, if it really does put out 80hp peak...why do they call it "equivalent" HP. Historically the EV folks use that term to lie about the actual HP when the spec for peak HP is much lower. If they are calling out peak HP, either that's the peak HP or it's not...there is no "equivalent" needed, so why include it?

Because if 99.9% of the hours on my D1-20 are at or under 2,400RPM, then a 12kW motor is exactly equal (if not outright better) than the 20hp engine 99.9% of the time.

Or flip it around if you prefer. Is a 20hp diesel engine equivalent to a "15kW" motor, or is that a "lie"? The motor will be able to maintain that output as long as you can feed it. The diesel won't. Now who's "lying"?

Is Oceanvolt's SD15 equivalent to a 45hp motor as they (used to) claim? Even if we're being realistic and assuming that most cat owners probably don't equip optional props and the Oceanvolt does?

From the sound of other prop articles and cruisers, it doesn't seem entirely out of the realm of possibility for say, the 95th percentile.

Still, I think I'd agree more with you than Oceanvolt. Which is probably why the only place I can find that claim on their site now is in a hidden section of the page source. I would probably call it "exaggeration" than a "lie", but poe-tay-toe, poe-tah-toe I guess.

So I like the Bali 4.1, which comes standard with D1-20s. So you probably spend most of your time near or under 9kW. It looks like you might (barely) get away with equipping Torqeedo 10kW pod drives. They're much cheaper than diesels. You get a bigger house bank. They're much much lighter. And you get back a cavernous amount of storage in your sugar scoops (which maybe you fill back up with a pair of generators, I dunno).

That looks doable, but marginal. But if Torqeedo keeps at it? A pair of 15 or 20kW pod drives for cats 45' and under 5 years from now looks like a no-brainer to me at those prices. $50K then probably covers your motors, a pair of 10kW generators, and a 30kWh battery. Which seems pretty price comparable to existing setups.

Originally Posted by valhalla360

I will admit at first glance it does look like the larger engine is significantly more efficient. but, you have to look at the actual torque/hp and fuel consumption. Just because an engine can produce a certain amount of toque/hp at a specific RPM doesn't mean that it is producing that amount

You're right of course. You've got two identical 3/4-ton trucks going down the highway. One is towing a trailer. Same RPM. Same engine. The one towing the trailer is going to get 7mpg while the other gets 18mpg.

But in this scenario the same is true for both engines. In fact, there's no way that the loaded up 20hp engine isn't working much harder for it's lunch. So I'd guess if anything, the playing field is even more lopsided. It probably doesn't do worse than 3.3L/hr. But the 45hp engine might do better than 1L/hr.

I don't own either, so all I can go off is their spec sheets and try to sound semi-educated.

The reason you don't automatically buy the bigger engine of course is price, and to a lesser degree for most I'm sure: Weight. Those bigger blocks weigh a lot!

[valhalla360]

Originally Posted by ssmoot

You didn't look at the specifications. Look for "Input power (peak) in kW". 63.4 for the "40hp" version.

You are correct but they don't provide the output power.

That's not really the same thing at all. They're mostly just raising boost pressure. There's no shortage of modified diesel trucks on YouTube blowing their head off.

Sure it's the same. Go to youtube and you can find guys burning out golf cart motors overloading them. Boost pressure is very much equivalent to dumping more kw into an electric motor. Do either for a few seconds and it's easy to jack up the HP. To do it for extended periods of time is where it gets tricky with either.

Because if 99.9% of the hours on my D1-20 are at or under 2,400RPM, then a 12kW motor is exactly equal (if not outright better) than the 20hp engine 99.9% of the time.

If you only take the boat out on calm days for a leisurely cruise around the harbor...sure less HP is fine. (PS: can you just list the HP or KW rating of the motor...I don't have all the model numbers memorized or are you trying to trick me into using the wrong spec)

Or flip it around if you prefer. Is a 20hp diesel engine equivalent to a "15kW" motor, or is that a "lie"? The motor will be able to maintain that output as long as you can feed it. The diesel won't. Now who's "lying"?

Define "as long as you can feed it". It you do it on a regular basis, yeah the engine will likely have a shorter life. But a diesel in good running order that can reach peak hp (no incorrect prop or dirty bottom limiting rpm), I would expect the diesel to keep going until I ran out of fuel on a typical cruising boat. Of course even if the diesel does fail, I'll bet in a head to head comparison, the diesel is running at peak output far longer than the electric motor. The electric motor might be fine but it will run out of juice far sooner unless you are feeding it with an even bigger diesel generator...in which case, you've just moved the diesel and made a much more complicated system.

Is Oceanvolt's SD15 equivalent to a 45hp motor as they (used to) claim? Even if we're being realistic and assuming that most cat owners probably don't equip optional props and the Oceanvolt does?

From the sound of other prop articles and cruisers, it doesn't seem entirely out of the realm of possibility for say, the 95th percentile.

Still, I think I'd agree more with you than Oceanvolt. Which is probably why the only place I can find that claim on their site now is in a hidden section of the page source. I would probably call it "exaggeration" than a "lie", but poe-tay-toe, poe-tah-toe I guess.

I wonder if enough people or possibly a dissatisfied customer called them out on the lie...that they pulled most of it (maybe just missed that one page). And no there is no way to twist that around to be anything other than a lie. There are well established industry tests for HP ratings...both ICE and electric (and if they didn't understand this and apply the comparable ratings, they are incompetent). You will note that the torquedo lists peak vs continuous output. If they were comfortable overloading the 15kw to produce 45hp, they should have just listed it as a 45hp and noted that it's a peak rating. That would be honest and comparable.

[ssmoot]

Originally Posted by valhalla360

You are correct but they don't provide the output power.

It's a brushless electric motor. It's not turning 30kW into heat.

Originally Posted by valhalla360

Sure it's the same.

Boosting an engine puts stress on the connecting rods, head, valve-train, pistons, beyond what they were engineered for. You could have a failure in 10 seconds or 10 years depending on how much boost.

That's really not at all similar to feeding so much juice to an electric motor that it ends up overheating after some amount of minutes and frying itself. If you have a thermal cut-off, there's no practical risk to this with any sort of reasonable input. You're certainly never going to see a working motor fry itself within 10 seconds without some sort of serious hidden defect already existing. Which is why pretty much every EV you see does it by design and under warranty. The same is not true for modifying your diesel. Bad things are going to happen if you try to get double the horsepower out of it.

Originally Posted by valhalla360

are you trying to trick me into using the wrong spec

The D1-20 is a 20hp engine. I thought being specific would be easier to see I'm not trying to cherry-pick. No trickery intended.

Originally Posted by valhalla360

I'll bet in a head to head comparison, the diesel is running at peak output far longer than the electric motor. The electric motor might be fine but it will run out of juice far sooner unless you are feeding it with an even bigger diesel generator...in which case, you've just moved the diesel and made a much more complicated system.

Well yeah you'd have a generator. You've got three diesels on your boat. You might even decide to throw on a couple high-output alternators. Getting rid of a diesel, and maybe even a pair of transmissions if you move to pods, seems to be a simplification to me if anything. In the EP scenario if one of your generators fails, you can still motor at full speed for awhile when you need to for example.

Originally Posted by valhalla360

I wonder if enough people or possibly a dissatisfied customer called them out on the lie...that they pulled most of it (maybe just missed that one page). And no there is no way to twist that around to be anything other than a lie.

I feel like you're just being unreasonable here. You're not even trying to consider the idea that they might be using different criteria than peak output, and making a genuine (if exaggerated IMO) claim.

Calling people liars just because they have a different opinion about what's important is not discussing in good faith. Clearly some owners here feel the claims are at least somewhat justified.

If EP were the norm and someone came out with this awesome peak-45hp diesel and you applied the same standard, you'd call that a lie as well. Because it's not "45hp". Engines that are rated for 45hp continuously are much heavier. It's "45hp for some amount of continuous hours". I've looked this up before. I think it's like 4 hours but I wouldn't swear to it.

People should be able to have honest disagreements without resorting to name calling.

[transmitterdan]

I like simple explanations so forgive me if this is overly simplistic.

So to summarize the argument the equivalency of EP 20HP to diesel 40HP is because the diesel is really only usable continuously at 20HP. And EP is sized so it can run flat out at full 20HP continuously.

Is that the theory in a nutshell?

[did-g]

Originally Posted by ssmoot

And this isn't even the worst example I could come up with. Say you wanted 20hp for cruising.

The (45hp) will give it to you at 1,200 RPM and consumes 1L/hr.

Hi,

No way you can get 20HP for one hour out of 1L of diesel in this universe. Are you sure you didn't mix up gallon and liter?

Ok after looking at Yanmar datasheet you may have confused max RPM output and engine output loaded by the propeller. If I don't mess it up at 1,200 RPM with the 'theorical' prop engine output is around 3HP. 20HP is at 2400 RPM with a more believable 5L/hr.

[ssmoot]

Originally Posted by transmitterdan

I like simple explanations so forgive me if this is overly simplistic.

So to summarize the argument the equivalency of EP 20HP to diesel 40HP is because the diesel is really only usable continuously at 20HP. And EP is sized so it can run flat out at full 20HP continuously.

Is that the theory in a nutshell?

I imagine that's what Oceanvolt was thinking.

I think a preferable ratio is somewhere north of 60%. Say 20kW vs 40hp. But you've got the crux of it.

[ssmoot]

Originally Posted by did-g

Hi,

No way you can get 20HP for one hour out of 1L of diesel in this universe. Are you sure you didn't mix up gallon and liter?

Ok after looking at Yanmar datasheet you may have confused max RPM output and engine output loaded by the propeller. If I don't mess it up at 1,200 RPM with the 'theorical' prop engine output is around 3HP. 20HP is at 2400 RPM with a more believable 5L/hr.

I'm not sure which of the power graph lines the fuel consumption graph correlates to. 3HP may certainly be correct. But then that would only be 2.24kW. Which would mean you could cruise around for about 12 hours on EP with a 30kWh battery. Which doesn't sound right to me?

That would also seem to be pretty out of line for generator load/fuel-consumption.

The Northern Lights will make 30kW at full load on 9.8L/hr. So based on that you could probably get around 26Kw+ "at the crank" from your pair of Oceanvolts for the same fuel burn as getting 2.24kW out of the comparable Yanmar? There's no way that can be right. Am I missing something?

[44'cruisingcat]

Originally Posted by transmitterdan

I like simple explanations so forgive me if this is overly simplistic.

So to summarize the argument the equivalency of EP 20HP to diesel 40HP is because the diesel is really only usable continuously at 20HP. And EP is sized so it can run flat out at full 20HP continuously.

Only if there's a big enough generator....

[DumnMad]

Originally Posted by 44'cruisingcat

Only if there's a big enough generator....

Depends on what you mean by continuously. Continuously for an hour, or, continuously for a week ??

The diesel motor also has limitations re fuel supply.