Oceanvolt Hybrid Motor

[harlem24]

From 36Ah to 63Ah is not double, but significant.
Samsung SDI cells used in the BMW i3 started at 60Ah per cell, got to 94Ah and are now at 120Ah per cell. This is doubled. All within the same form factor.
https://www.samsungsdi.com/automotiv...tery-cell.html
They are not mentioning the 120Ah version on the website, which I think is because they are exclusivly used for BMW.

[harlem24]

And since you can put the new cells in as replacement for even the 60Ah, it is 100% sure that the form factor is the same.
I can send you a link, okay it's in German, where someone did exactly this.

[harlem24]

And an other link about the evolution of the cells in the BMW i3.
https://electrek.co/2018/09/28/bmw-i...upgrade-range/
Do you believe me now?
The same cells are used by Torqeedo to form the Power-5000 48V battery and if you decide to get a deep blue drive you will get the complete battery pack of the i3 including BMS, cooling and packaging.

[ssmoot]

A popular item a few years ago might be a CALB 400Ah cell, with 93Wh/kg. Today you can buy a 280Ah cell (same basic chemistry, LiFePO4) with 172Wh/kg.


That's a pretty dramatic improvement in gravimetric density.


Most of this improvement comes down to improved manufacturing and packaging. It's not something, I'd bet, you can count on seeing a trend line for over the coming decade. Not without new chemistries. External pack dimensions are not really a good way of looking at it. Volumetric efficiency hasn't changed all that much. The highest density 18650 cells from 5 years ago (say 3200mAh) aren't much different than the best you can get today (say 3400mAh typically) even if some chinese brands frequently make outlandish and false capacity claims.


All that said, being able to drop 70kWh on your boat in 418kg for about $12K today is a big improvement over where we were just a few years ago. And once the tariffs lift, we can probably see that price drop under $10K I'd expect.

[mcarthur]

Originally Posted by ssmoot

A popular item a few years ago might be a CALB 400Ah cell, with 93Wh/kg. Today you can buy a 280Ah cell (same basic chemistry, LiFePO4) with 172Wh/kg.


That's a pretty dramatic improvement in gravimetric density.


Most of this improvement comes down to improved manufacturing and packaging. It's not something, I'd bet, you can count on seeing a trend line for over the coming decade. Not without new chemistries. External pack dimensions are not really a good way of looking at it. Volumetric efficiency hasn't changed all that much. The highest density 18650 cells from 5 years ago (say 3200mAh) aren't much different than the best you can get today (say 3400mAh typically) even if some chinese brands frequently make outlandish and false capacity claims.


All that said, being able to drop 70kWh on your boat in 418kg for about $12K today is a big improvement over where we were just a few years ago. And once the tariffs lift, we can probably see that price drop under $10K I'd expect.

Ooo - where to get 70kWh of actual CALB 280's from for US$12k?

[StuM]

Originally Posted by mcarthur

Ooo - where to get 70kWh of actual CALB 280's from for US$12k?

Do CALB make anything larger that 180's and 200's?

[StuM]

Originally Posted by mcarthur

Ooo - where to get 70kWh of actual CALB 280's from for US$12k?

Do CALB make anything larger that 180 and 200 cells?


Edit: Oops, yes they have a CA400. But AFAIK, no 280's

[ssmoot]

Originally Posted by mcarthur

Ooo - where to get 70kWh of actual CALB 280's from for US$12k?

Sorry, I wrote that in a confusing way. The 400Ah cells are CALB. The 280Ah cells are Jiangxi Ganfeng cells as far as I know. The QR code is a bit small for my phone to pick it up and I'm lazy. I have the 150Ah versions.

[harlem24]

If somebody is looking for cheap LiFePo batteries from a company not selling through alibaba, have a look here:

https://www.epropulsion.com/e-series-batteries

9kwh for 4k$ is imho an absoulte bargain. And with 87kg not that heavy either.
Torqueedo are double.

[mcarthur]

Good find. Note that max discharge is "only" 150A, so max continuous to the electric motor of 7.2kW (and many motors being about 90% efficient including reduction and prop shaft losses meaning perhaps 6.5kW getting to the prop. That could easily be 5+kn for many a boat (for an hour or so )

[harlem24]

Yeah, with one unit.
From how I understand batteries, if you put them in parallel you can put more load on it.
So there would be at least 50% more load possible on a two module battery. And 10kW on a 18kWh should be possible without even stressing the system and well below the poosible 14kW.
Put the price is still extremly cheap and it's a LiFePo chemistry that I would prefer over the i3 cells Torqueedo uses in there 48V 5kWh battery. NMC is able to ignite itself, LeFePo is not. And fire on a boat that is almost impossible to put out would be a nightmare.

[harlem24]

Here is an interessting interview with Sailing Uma, who have just upgraded to an Oceanvolt Saildrive...

https://www.youtube.com/watch?v=xOAXi5huV1U

[fugue137]

Originally Posted by valhalla360

What do you hope to gain with a hybrid?

A few things could be gained:

First, I'd argue that it is far better than a car in stop&go traffic: when there's no wind, you're discharging, and when there's wind, you're recharging. You might need no fossil fuel ever again.

Second, over the last 5 years we've learned a lot about the harms of noise pollution. It's far more than a minor irritant: it causes all the diseases of chronic stress, from heart disease to learning disabilities to anger and violence. And then there's the harm noise causes to marine ecosystems. And then there's the hazard to navigation of denying you the use of one of your long-distance senses. Mufflers are a start, but electrics are vastly better.

Third, and most important: for how long have we known that we MUST stop using fossil fuels? At least half a century, and the whole time, we've been learning over and over again that it's more urgent than we thought. It's understandable, perhaps, for heavy industry to take a little while to transition, but it's utterly beyond belief that we're still burning fossil fuels just for fun.

Sailors have a rather unique opportunity: our mode of transport/fun is not entirely harmless (William McDonough aside, few things we do are actually good), but is by and large pretty benign, and pointing in a less-bad direction. We could be setting an example for the world to follow.

So yes, I'd argue that some things could be gained by going electric. I know the technology has some serious drawbacks as well, but I'd like to argue for counting the benefits and drawbacks fairly against those of fossil fuels.

[valhalla360]

Originally Posted by fugue137

A few things could be gained:

First, I'd argue that it is far better than a car in stop&go traffic: when there's no wind, you're discharging, and when there's wind, you're recharging. You might need no fossil fuel ever again.

Second, over the last 5 years we've learned a lot about the harms of noise pollution. It's far more than a minor irritant: it causes all the diseases of chronic stress, from heart disease to learning disabilities to anger and violence. And then there's the harm noise causes to marine ecosystems. And then there's the hazard to navigation of denying you the use of one of your long-distance senses. Mufflers are a start, but electrics are vastly better.

Third, and most important: for how long have we known that we MUST stop using fossil fuels? At least half a century, and the whole time, we've been learning over and over again that it's more urgent than we thought. It's understandable, perhaps, for heavy industry to take a little while to transition, but it's utterly beyond belief that we're still burning fossil fuels just for fun.

Sailors have a rather unique opportunity: our mode of transport/fun is not entirely harmless (William McDonough aside, few things we do are actually good), but is by and large pretty benign, and pointing in a less-bad direction. We could be setting an example for the world to follow.

So yes, I'd argue that some things could be gained by going electric. I know the technology has some serious drawbacks as well, but I'd like to argue for counting the benefits and drawbacks fairly against those of fossil fuels.

Ummm...in this discussion, a hybrid is a combination of ICE and electric motor with a modest battery bank. Sometimes you can get a few miles under electric alone (in cars referred to as Plug-In-Hybrid), other times, the electric is just leveling out the highs and lows of power demand (in cars this is your basic hybrid).

Hybrid as opposed to a pure ICE or a pure Battery Electric propulsion system.

What you describe is a pure Battery Electric system with the ability to recharge using a hydro-generator when under sail. That can be viable if you are willing to live with drastic reduction in capability and you sail a lot relative to the amount of motoring. Where it breaks down is if you want to do some typical coastal cruising like running the ICW where you want to cover back to back 50 mile days in 6-8hr travel each day.

If you just go out for the weekend purely to sail with no destination in mind, pure battery electric propulsion is perfectly viable to get you in and out of a slip. Likewise if you mostly do long multi-day passages where you will be sailing most of the time anyway, it's viable.

[transmitterdan]

A pure electric boat requires a massive solar array for anchoring out at remote idyllic harbors.

If one is concerned about making a carbon footprint one would never cruise in a boat. The tiny amount of fuel needed to maneuver a sailboat is minuscule compared to that used in the manufacturing process. Plus the fuel burned getting all the food, water and other supplies to whatever exotic destination you happen to be dwarfs any fuel the boat might have used to get there itself. Electric drive is not going to help the environment. Not to mention all the heavy metals and chemicals used to manufacture electric systems.