Electric Main Drive(s)

[Aussiesuede]

Originally Posted by Nordic cat

So the battery on my 3000$ Dell laptop is some cheap crappy battery?????

Actually, yes. The controller for that lithium ion battery in your laptop is purposely degraded in efficiency to keep it safe. Lithium Ion is very unforgiving to voltage spikes and will easily catch fire. Therefore the charge controllers operated at less efficiency to reduce said risk. In doing so, the heat generated is increased - reducing the number of "real world" cycles available.

The advent of lithium phosphates mitigates some of these problems since a voltage fire can be suppressed by the phosphate itself - allowing commercial manufacturers to install controllers that are less resistant - thus generating less heat and giving you more real world life cycles than does lithium ion.

A 20v / 4000ma lithium phosphate battery in your laptop, of the same form factor as your current lithium ion, would yield operating times in about the 10 hour range. The battery doesn't actually have more storage capacity - just more efficient control. When these batteries hit the market in 5 years or so, you'll notice that they still show 3000-4000ma capacities, yet 10 hour run times. The technology exists today - it just isn't cost effective (and won't be until laptop prices bottom out AND there is a wide demand for runtimes longer than the current 3-4 hour standard)

Originally Posted by Nordic cat

And what perchance was the number of cycles you used in your spreadsheet to show up the advantage of the batteries you are selling?

Was it not 5000, and now you claim this is just around the corner?

3000 cycles is thoretically obtainable. But in the real world, such a system would never be designed for consumer use that would ever approach this - since the accompanying risk of lithium explosion would be untenable. Therefore, commercial manufacturers will continue to control efficiencies to keep the batteries safe. That means increased heat, which ultimately in turn means fewer life cycles.

If you put a dam in the middle of a river, you create more pressure - and heat. The efficiency of river flow around a dam is less than that of a free flowing river. That lithium controller is basically a dam restricting the free flow of energy (in and out). That restriction will generate more heat.

[s/v Beth]

I don't think people ought to apologize for using Lead-acid batteries. They seem to have a pretty good life (if they are kept charged) and they are recycled. How much is really wasted? Just don't release the Lead into the environment.

[graham.g]

I have a voyager 10 metre catamaran with 2 x 48 volt 10kw electric pods as the cruise ships and a 13kw generator all by fischer panda and if i had gone for the 11kw generator the weight is about the same as the twin diesel version but the advanteges seem to me great as we have 3kw mains supply enabling use of electric kettle,food mixer and induction hob, ( my wife likes cooking).
the diesel self starts when battery voltage gets low and charges 4 x oddysey pc2250 batteries which drive the boat and inverter and can be run almost flat and as they are a pure lead make up they are easy to recycle.
The biggest advantage is NOISE or lack of it and at lower speeds or motor sailing it is so relaxing to hear the birds and other poeple.
The generator is on less than 50% of the time and is much quieter than diesel as not connected to hull of boat except through cables for charging.
There are some small teething problems but the concept is GREAT lthough i am biased.
The boat (CHI-CHI) is at Plymouth and next year will head back to Baltic so if you want a demo get in touch.
graham.garner@btinternet.com

[shnean66]

Originally Posted by fastcat435

there are at least 50 different types of Lithium batteries and the ones used in laptops and cell phones are of the lowest quality since the aging of the laptops and phones does not make it necessary to install high end Lithium battery's in these units.

I have never seen any device or battery living up to the promised recharge cycles. If you abuse and neglect batteries they die pretty fast.
I have yet to be convinced that if I just buy more expensive batteries these problems are completely gone.

Originally Posted by fastcat435

The sky is not even the limit anymore.
...
the development of Hybrid boating will continue and in not to long there will be a company with a good solution , this will only be achieved by trying to improve and keep on trying

I believe pretty amazing things are achievable if you don't have to watch your pocket. But I am not the NASA and I am not ready to sink my money into other people's experiments.

Beside technical issues it's just not an economical choice (yet). Maybe in a couple of years after we learned some lessons from electrical cars in the mass market.

And until it becomes very much mainstream you still have no choice but to cruise US or European waters just in case you need some help.

[osirissail]

- - Well, Gideon is not incorrect - per se. What is missing is the fact that "cycles" available for the life of a given battery are charted against "depth of discharge." It is a logarithmic curve. With only 1% to maybe 5% discharge before recharging will yield a cycle life right up there in the clouds. Take 50% out of the batteries before recharge and you will be back down on the ground. Take his full discharge - "just imagine 100 kilo of batteries 40 KWh usable power or 4 hours of cruising with a 20 Kw motor at 50 % power?" - and you will see maybe somewhere near two cycles as the life of the batteries.
- - "Fuel Cells" have a higher probability of being the "next step" in efficient "green" power supplies. That is why NASA and such "outer space" craft use them instead of batteries. It will just take time for "Fuel Cells" to be developed enough to supply large amounts of power at prices that are competitive to fossil fuels.
- - Battery technology is being driven hard by the need for non-pollution automobiles. That is where you will see the break-thoughs. Currently all other "better batteries" are stuck in the low power/low time frame. Some "exotic" batteries are used in aviation/space applications - regardless of cost - for safety reasons. Heat is the big killer of batteries and charging and discharging generates significant heat. Aviation drove the invention of the AGM battery and then the Nickel batteries because under a high draw down situation and/or excessive charge situation batteries will enter a "thermal runaway" and explode violently spraying acid everywhere. Something not very desirable in an airborne aircraft or spacecraft.

[Talbot]

Originally Posted by osirissail

-- - "Fuel Cells" have a higher probability of being the "next step" in efficient "green" power supplies. That is why NASA and such "outer space" craft use them instead of batteries. It will just take time for "Fuel Cells" to be developed enough to supply large amounts of power at prices that are competitive to fossil fuels. .

Fuel cells are available now, but expensive. Their biggest drawback is how to "recharge". The best hope at the moment is the hydrogen fuel cell. This is already sufficiently developed to enable deployment - except how do you get the supplies of hydrogen. For a car, you could fill up at a garage! but range is still limited. Therefore there needs to be a technology for creating that hydrogen while in transit. This technology already exists on the large scale, and large hydrogen fuel cells have been installed in buildings to provide all the back-up power based on this technology. However, at the moment, it hasnt been made small enough for use in a car/boat. Also the best source of the hydrogen is diesel fuel!

[Therapy]

Originally Posted by Talbot

Also the best source of the hydrogen is diesel fuel!

Isn't it interesting that oil (and it's derivatives) still holds the most energy.

I hope something better comes up soon but am not holding my or my son's breath.

[fastcat435]

Hello Orissail the 3000 cycles given are with 80 % d.o.d. or almost completely discharged
and after the 3000 cycles 80 % level of charge is still possible, testing has been done and the odd thing is that in the first 100 or so charges the power level went up to 105 % or the KwH actually improved.

[osirissail]

Originally Posted by fastcat435

Hello Orissail the 3000 cycles given are with 80 % d.o.d. or almost completely discharged
and after the 3000 cycles 80 % level of charge is still possible, testing has been done and the odd thing is that in the first 100 or so charges the power level went up to 105 % or the KwH actually improved.

- - Assuming we are talking about the Lithium technology batteries in post by Aussiesuede - he goes on to say >>> 3000 cycles is theoretically obtainable. But in the real world, such a system would never be designed for consumer use that would ever approach this - since the accompanying risk of lithium explosion would be untenable. Therefore, commercial manufacturers will continue to control efficiencies to keep the batteries safe. That means increased heat, which ultimately in turn means fewer life cycles.<<<
- - I still feel as soon as the researchers and manufactures can lick the storage battery limitations and make them cost-effective or even nearly cost-effective as infernal combustion engines then we will see a partial migration to electric power. When they solve the "replacing the power used" problem without reliance on infernal combustion gensets then I predict a massive movement to electric propulsion. When that will happen, who knows? Maybe on good thing about the "global warming" lobby is their pressure to spur research and developments in these areas which probably would have been totally ignored under other circumstances. There are probably many ways to accomplish this but first the researchers have to find and try out a million alternatives, one at a time to see if they actually work. That takes time and money.

[fastcat435]

I am talking about LifePO , lithium iron phospate industrial quality batteries, these units have been tested and 3000 cycles are achieved, an electrical regenerating system is more expensive than a diesel system however there are advantages that a diesel system cannot offer like regeneration, no smoke, sound, vibration, sooth or airpollution .
You are right it takes time and money to find the right solution and that is what many people and company,s are doing.

[YOGAO]

FWIW, there is a pretty good write-up in Wikipedia on LiFePO4 batteries.

Fair Winds,
Mike

[scotte]

Originally Posted by fastcat435

I am talking about LifePO , lithium iron phospate industrial quality batteries, these units have been tested and 3000 cycles are achieved, an electrical regenerating system is more expensive than a diesel system however there are advantages that a diesel system cannot offer like regeneration, no smoke, sound, vibration, sooth or airpollution .

Maybe, someday (and I can't wait for that day) - but if you do the math with today's available technology, there's no way you can regenerate the power used by 3 hours of motoring in 24 hours of straight sailing without a massive number of solar panels+wind generators. And that's just to recharge the drive batteries, not including any additional electric load. So I think for the foreseeable future, anyone with an electric drive+regeneration system (for example, the Lagoon 420s - the only production cat I'm aware of with such a system), a generator is still a requirement - hence you'll still have smoke, sound, vibration, soot (sooth?), and airpollution.

As far as the all-electric system costing more, I'm curious if African Cats is still going to offer this system at no additional cost over conventional diesel drives?

[osirissail]

- - I got to the Lagoon 420 website and there is some good information there and especially their page devoted to the electric propulsion: catamarans LAGOON : construction, vente et location de catamarans de croisière
Quite complicated system with lots of batteries plus huge genset. Interestingly, the motors cannot run off the genset. The genset powers a special 72VDC battery charger that recharges the motor batteries and kicks in a maximum of 40% motor power limiter in this configuration. That might get scary in an emergency situation trying to stay off rocks. But the boat is also sold with standard diesel engine drives.

[osirissail]

Correction to my post 493 - In Mode 4 the genset provides power to the house and battery charger which runs the motors with the 40% power available restriction. In mode 5 the batteries and genset power the motors but not the house systems. Full power is available until the batteries discharge then the genset through the battery charger powers the motors with the restriction. Like I said a rather complicated system. And the 41 ft cat weighs in at 30,000 lbs. I wonder what normally 41ft cat's weigh? FastCat435 - what is the displacement of the electric version of your African Cat?

[fastcat435]

Originally Posted by scotte

Maybe, someday (and I can't wait for that day) - but if you do the math with today's available technology, there's no way you can regenerate the power used by 3 hours of motoring in 24 hours of straight sailing without a massive number of solar panels+wind generators. And that's just to recharge the drive batteries, not including any additional electric load. So I think for the foreseeable future, anyone with an electric drive+regeneration system (for example, the Lagoon 420s - the only production cat I'm aware of with such a system), a generator is still a requirement - hence you'll still have smoke, sound, vibration, soot (sooth?), and airpollution.

As far as the all-electric system costing more, I'm curious if African Cats is still going to offer this system at no additional cost over conventional diesel drives?

Hallo Scotte

the standard inboard electric drive system with AGM batteries is priced the same as the diesel version, the green motion retractable version with Lithium batteries is extra.
A generator is not a requirement but we advise one for situations like the Doldrums with days with very little or no wind.
No generator means no diesel and that saves a lot of weight making the cat use even less energy or need less wind to move.
The day where you can motor for 3 hours and then regenerate the energy used within 24 hours is very close or should i say around the corner all depending on wind and thus sailing speed of course.