Re: Plastic fairings for trolling motor shafts
Great thank you will have to look into it Cheers
On Saturday, January 14, 2023, 17:03, cpcanoesailor via groups.io <cpcanoesailor@...> wrote: Hi, I just wanted to mention that I found a source of light weight PVC fairing stock at?
Dennis from uflyit.com sold me a 15" piece of their smallest section fairing for $10 plus shipping. It fit perfectly around the round shaft of my modified trolling motor, and was way less messy than making a fairing from epoxy, glass and foam.
Looking forward to less gurling and more efficiency when motoring this year.
|
Plastic fairings for trolling motor shafts
Hi, I just wanted to mention that I found a source of light weight PVC fairing stock at?
Dennis from uflyit.com sold me a 15" piece of their smallest section fairing for $10 plus shipping. It fit perfectly around the round shaft of my modified trolling motor, and was way less messy than making a fairing from epoxy, glass and foam.
Looking forward to less gurling and more efficiency when motoring this year.
|
Re: Li-ion battery designer commentary
Weight is a factor with big displacement boats, for an opposite reason.? For example,? I'll be taking out 10,000 lbs of Detroit Diesel 8v71s and installing motors weighing +/- 400 lbs. I need all the battery weight I can get.
On Sun, Jan 1, 2023 at 8:45 AM, Kevin Pemberton <pembertonkevin@...> wrote: Yah! If you're loading your racing boat up with lithium and your wanting to plane, energy to weight ratio is big. However when displacement hulls are the major players weight becomes less of a factor.?
If I consider my sailboat, it had 5000 lbs. Of lead bolted on the underside. Had a 5411 universal diesel originally installed. Battery density becomes a non-issue.?
I of course must take into account recyclable resource when I consider the avenue I take. Why? Well because I got into sail-electric to help the environment. This required my research into the processes used to make my components.?
So what are my components?
Used off grid solar panels, replacing aged sails. Reusing panels keeps those panels out of the landfills, and have a cost benefit. (Roughly 3000w used panels vary from rated values).?
Carbon lead Batteries not only have higher c ratings than lead acid, they have the same ability to be recycled. Recycling of lithium Batteries are a completely different subject.? As well as the strain on the environment during the initial refinement required.?
With the removal of sailing gear, the lead ballast can be replaced by lead Carbon power storage. (3000# ÷ 156#=53 NSB batteries). Not to say that you would need to, but the lead in the keel replaced by blues would be 2000amp hours at the typical 48volt system without changing the water line.?
48 volt 200ah bank was at the time of purchase 1800 usd. In conjunction with 3000 watt solar bank,? and 10kw drive. Keeps the battery bank usable at less than hull speed.?
In summary: if I were talking to a group of car enthusiasts, I would have to consider destroying the environment, but I am not! I am talking to a group of mostly displacement hull enthusiasts? what I am encouraged about is my post was considered.?
Have a wonderful day!! On Sat, Dec 10, 2022, 8:45 AM twowheelinguy via <twowheelinguy= [email protected]> wrote:
I've heard good things about NorthStar batteries, and I've used the Trojan "carbon infused" batteries but I wasn't that impressed. Sure, they worked a lot better, but they still don't hold a candle to Lithium chemistry. And carbon infused lead batteries are a lot more expensive so that cancels out any cost advantage they might offer.? ?
The problem with lead chemistry is not it's capacity to store energy, it actually provides a pretty good value for that. The problem is you lose your ass putting the energy in and taking it out, especially if you want to do it in a hurry. If you have a system where you can charge slowly and only do low current draws with low depth of discharge, you could have argued that lead was a better value than lithium until recently. But now that you can buy a ready to use kWhr of lithium storage capacity for $250, lead has just about lost any price advantage it had and once it hit's $150/kWhr it will pretty much be game over for the lead battery industry. I don't think lead will ever completely be dead but it will soon be relegated to only very specialized applications imo.?
I'm on a cruise right now running my new lithium batteries hard for the first time and I can state UNEQUIVELENTLY they are definitely in another league than ANY lead batteries I've ever used or heard of and I've cruised the Arc over 5000 miles using various lead batteries over the last 12 years. As a long time holdout for using lead acid chemistry, I have to agree with Elon Musk now when he said, "lead sucks".?
You can still debate the cost benefit ratio of lead for some specialty applications but comparing the performance of lead to lithium is like comparing little league baseball to the major league.? Lithium is that much better, imo.
Capt. Carter
On Saturday, December 10, 2022 at 06:57:55 AM EST, F. Neil < fneilss@...> wrote:
At >60 pounds per kWh, and limited 50% depth of discharge (for maximum lifespan), these Northstar carbon lead batteries are not really in the same class as Lifepo4 batteries for applications where energy density is an issue...?
|
Re: Li-ion battery designer commentary
Excellent treatise, Kevin.? And no criticism here of the logic justifying using lead-acid batteries for displacement water craft propulsion based on the factors noted.? You could also add to the factors: Cycle Life.? A 2000-3000 charge cycle life is meaningless for most recreational boaters, let alone displacement craft that might only get used 1-2x/month.? In my case, this was a major factor in my early analysis for not considering lithium alternatives since most arguments for lithium vs lead are based on a 3-5x effective cycle improvement.? I mean, if, like me, you average only about 20-30 outings a year and assuming you only have to charge the pack 4x, that’s just 4 cycles per year (what I typically do now).? It’s hard to rationale paying more to improve cycle life when a perhaps 400 charge cycle life lead alternative would on paper last 100 years. ? But that’s not the whole picture with cycle life and lead.? Lead acid batteries usually die prematurely well before reaching the rated cycle life. ?Often 10x sooner, especially and mostly in cases where cycle time is very extended---and that is particularly the case with marine pleasure displacement craft like mine.? My boat went thru 3 sets of lead acid deep cycle golf cart batteries all of which sulfated prematurely because I could not keep them maintained as they needed to be to realize anything close to a long cycle life.? Further, as this progression deepened, in each case, it was a guess and a worry how much capacity my pack actually had after being charged. ?At some point you get really tired of this lack of dependability.? Not to mention the hassle to haul out a raft of lead each time and haul it off to the recycler. ?Have you seen how nasty the recycle process is with lead?? I suppose in the States it might be environmentally sound but there are videos online of it being done in an open air shop in places in India and I wonder how eco-friendly the whole process really is. ? Add to this the fact that there are a raft of ex-automotive EV battery packs out there with gobs of cycles and capacity left in them with cost/kwh that rivals or exceeds the cost for comparable lead-acid alternatives. ?Saving those packs from the recycler or junk heap has eco value.? And so, some of us here (e.g. me) have gone to lithium thru this path, reusing ex-land EV batteries for our boat propulsion.? Result: Affordable and high performance packs with high dependability in terms of absolutely knowing how much capacity your pack has left.? Packs that otherwise might have been left to rot on the auto junk heap, packs that can sit in our displacement craft for months unattended with zero degradation, very much unlike lead. ?Packs that will literally outlast our boats.? Replacing this pack in the future is no longer a necessity at all.? Hard to see the end-of-life recyclability as a big argument against lithium for low-cycle, displacement E-boat propulsion. ? Thanks for the points you made.? You made them well. J ? -Myles Twete, Portlandia ?
toggle quoted message
Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of Kevin Pemberton
Sent: Sunday, January 1, 2023 8:45 AM
To: [email protected]
Subject: Re: [electricboats] Li-ion battery designer commentary ? Yah! If you're loading your racing boat up with lithium and your wanting to plane, energy to weight ratio is big. However when displacement hulls are the major players weight becomes less of a factor.?
|
Re: Li-ion battery designer commentary
Yah! If you're loading your racing boat up with lithium and your wanting to plane, energy to weight ratio is big. However when displacement hulls are the major players weight becomes less of a factor.?
If I consider my sailboat, it had 5000 lbs. Of lead bolted on the underside. Had a 5411 universal diesel originally installed. Battery density becomes a non-issue.?
I of course must take into account recyclable resource when I consider the avenue I take. Why? Well because I got into sail-electric to help the environment. This required my research into the processes used to make my components.?
So what are my components?
Used off grid solar panels, replacing aged sails. Reusing panels keeps those panels out of the landfills, and have a cost benefit. (Roughly 3000w used panels vary from rated values).?
Carbon lead Batteries not only have higher c ratings than lead acid, they have the same ability to be recycled. Recycling of lithium Batteries are a completely different subject.? As well as the strain on the environment during the initial refinement required.?
With the removal of sailing gear, the lead ballast can be replaced by lead Carbon power storage. (3000# ÷ 156#=53 NSB batteries). Not to say that you would need to, but the lead in the keel replaced by blues would be 2000amp hours at the typical 48volt system without changing the water line.?
48 volt 200ah bank was at the time of purchase 1800 usd. In conjunction with 3000 watt solar bank,? and 10kw drive. Keeps the battery bank usable at less than hull speed.?
In summary: if I were talking to a group of car enthusiasts, I would have to consider destroying the environment, but I am not! I am talking to a group of mostly displacement hull enthusiasts? what I am encouraged about is my post was considered.?
Have a wonderful day!!
On Sat, Dec 10, 2022, 8:45 AM twowheelinguy via <twowheelinguy= [email protected]> wrote:
I've heard good things about NorthStar batteries, and I've used the Trojan "carbon infused" batteries but I wasn't that impressed. Sure, they worked a lot better, but they still don't hold a candle to Lithium chemistry. And carbon infused lead batteries are a lot more expensive so that cancels out any cost advantage they might offer.? ?
The problem with lead chemistry is not it's capacity to store energy, it actually provides a pretty good value for that. The problem is you lose your ass putting the energy in and taking it out, especially if you want to do it in a hurry. If you have a system where you can charge slowly and only do low current draws with low depth of discharge, you could have argued that lead was a better value than lithium until recently. But now that you can buy a ready to use kWhr of lithium storage capacity for $250, lead has just about lost any price advantage it had and once it hit's $150/kWhr it will pretty much be game over for the lead battery industry. I don't think lead will ever completely be dead but it will soon be relegated to only very specialized applications imo.?
I'm on a cruise right now running my new lithium batteries hard for the first time and I can state UNEQUIVELENTLY they are definitely in another league than ANY lead batteries I've ever used or heard of and I've cruised the Arc over 5000 miles using various lead batteries over the last 12 years. As a long time holdout for using lead acid chemistry, I have to agree with Elon Musk now when he said, "lead sucks".?
You can still debate the cost benefit ratio of lead for some specialty applications but comparing the performance of lead to lithium is like comparing little league baseball to the major league.? Lithium is that much better, imo.
Capt. Carter
On Saturday, December 10, 2022 at 06:57:55 AM EST, F. Neil < fneilss@...> wrote:
At >60 pounds per kWh, and limited 50% depth of discharge (for maximum lifespan), these Northstar carbon lead batteries are not really in the same class as Lifepo4 batteries for applications where energy density is an issue...?
|
Re: Newbie looking for guidance
I concur with many here - go to thunderstruck-ev.com for complete kits. Their reduction/motor mount combo makes installation straight forward.?
if you have data - engine RPM - prop RPM - at the speeds you are looking for - this will help in choosing a reduction ratio.?
Once you choose operations time, then you can calculate batter size. I’m an advocate if building your battery from LiFePO4 cells with a suitable BMS ?I did read about a US company selling complete batteries Trophy Battery that seem like quality products.
?
|
Re: Newbie looking for guidance
That is a good advise, in general ! Always put a thrust bearing in the drive line. Anywhere, between the prop and the main shaft of the motor/engine.
Carsten
On Thursday, 29 December 2022 at 23:44:33 CET, kurtphone@... <kurtphone@...> wrote:
The prop has an optimum speed and the motor has an optimum speed. Proper ratio in the gear reduction is when they match. My initial installation at 2.5 to 1 was over propped and I could “overload” the motor. At 3 to 1 it drives the boat much like the old 30hp Volvo only more controllable.?
I noticed no significant change in the noise
level with my ratio changes.?
Thunderstruck advises to not use direct drive without some sort of thrust bearing to save the electric motor bearings from the thrust loads.?
|
Re: Newbie looking for guidance
The prop has an optimum speed and the motor has an optimum speed. Proper ratio in the gear reduction is when they match. My initial installation at 2.5 to 1 was over propped and I could “overload” the motor. At 3 to 1 it drives the boat much like the old 30hp Volvo only more controllable.?
I noticed no significant change in the noise
level with my ratio changes.?
Thunderstruck advises to not use direct drive without some sort of thrust bearing to save the electric motor bearings from the thrust loads.?
|
Re: Newbie looking for guidance
Hi Tom,
Your boat looks great!
If you're considering something low power on the order of 3 HP and have more time than money, you might get a motor and controller for $100-$200.? Study the torque charts and your propeller geometry to see if you need to modify the prop for higher RPM.? Get a set of 12V (nominal) LiFePO4 batteries for another $100.? You may have an iteration or three to resolve the differences between theory and water.? Once you have it working, buy additional batteries according to how long you want it to run before you switch to oars.
Cheers
Halden
|
Re: Newbie looking for guidance
What kind of boat do you have, Tom ? Here we have all kinds of boats...
What is an "A4" engine (please describe), and what kind of connection do you have between the engine and the prop ?
If you strip the fossile engine, it will be hell to put it back. Good thing is - you will never want to go back !
Carsten
On Thursday, 29 December 2022 at 23:09:42 CET, Tom@... <tom@...> wrote:
Thank You All, It is the 30hp A4 currently installed I know converting from a good running A4 to electric isn't exactly logical but what in boating is?? I do want to try going electric, it suites the way we use her. If I do it I will use the existing running gear, as easy as it to acess the A4, I may want to put it back in at times. The hull is very efficent up to 4-6kts (it gets there at idle now)? Currently if I want to run a trot line I need to drag two 5 gal buckets to go slow enough...The electric will allow for that slow troll. ![]() Tom
|
Re: Newbie looking for guidance
Thank You All,
It is the 30hp A4 currently installed
I know converting from a good running A4 to electric isn't exactly logical but what in boating is?? I do want to try going electric, it suites the way we use her.
If I do it I will use the existing running gear, as easy as it to acess the A4, I may want to put it back in at times.
The hull is very efficent up to 4-6kts (it gets there at idle now)?
Currently if I want to run a trot line I need to drag two 5 gal buckets to go slow enough...The electric will allow for that slow troll.
Tom
|
Re: Newbie looking for guidance
I have to disagree with ONE thing Matt said. The one penalty for oversizing may only be economic but it is real and could be significant between 3 and 10 HP.
If cost is a minor consideration I'd say a nominal 5-6 kW system would be the sweet spot for most needs and bang/$$$. If your budget is tight, something in the 3 HP range should still push her with authority but might be lacking a little in heavy weather and strong currents. IMO
Capt. Carter Www.shipofimagination.com
On Thu, Dec 29, 2022 at 9:54 AM, Matt Foley <matt@...> wrote: Assuming this was a 18hp Atomic??
You could definitely gain by going with a larger prop. Since you cant go much bigger and you wont need much power at all to push this 6 knots its probably not worth it.?
Personally I think a 3kw motor would be plenty for this boat to putt around.? Since there isn't really any penalty in oversizing, I might go with a 10kw. This would match or exceed the performance of the Atomic.?
I would also try and go direct drive. It may overheat at top speed, but you wont have the battery capacity to keep it there long enough to be an issue.?
I typically don't recommend anything other than LFP for boats. I wouldn't be apposed to it here as long as its in a portable, waterproof enclosure. This will help keep the weight down and in turn have a larger capacity capable of pushing 10kw motor.?
Matt Foley? Sunlight Conversions Perpetual Energy, LLC 201-914-0466
On Wednesday, December 28, 2022 at 12:49:33 PM EST, twowheelinguy via groups.io <twowheelinguy@...> wrote:
I was thinking the same thing as Al. If that Atomic 4 is running good why convert?? A4s are super quiet and efficient ICEs. With the exception of using gasoline as its fuel, A4s are awesome and they would definitely be the best way to go 20 kts. But if you have an aversion to gas on a boat , don't want to listen to and smell diesel and don't care of you ever go 20 knots again then that boat looks like it would be an excellent electric boat.?
I'd guess with a solar canopy it could cruise 5 kts just off solar on a sunny day.
If you're sure? electric is the best for you, Thunderstruck is a good place to look for an all inclusive kit for a good price but if you really have a tight budget I'd look at golf cart conversion? kits. I've been running one for 10 years. To say it's a little underpowered is an understatement but it will push the Arc 4 mph on nothing but sunshine and make 5 kits if I suck on the batteries hard. It won't take much to get that boat up to 6 or 7 mph if that's all you want and if you do want to go much faster it won't do it for long unless you spend a fortune on batteries and a lot more on a motor and controller that you won't use most of the time.
Gas or electric though, it's a cool boat.
Capt. Carter Www.shipofimagination.com On Wed, Dec 28, 2022 at 11:16 AM, 63urban <63urban@...> wrote: But wouldn't that be far less efficient and a little more noise?
Nick
Sent from my Bell Samsung device over Canada's largest network.
-------- Original message -------- From: kurtphone@... Date: 2022-12-28 10:35 a.m. (GMT-05:00) Subject: Re: [electricboats] Newbie looking for guidance
i got my kit from Thunderstruck as well. Two thumbs up! I just changed sprockets/ratios on the gear reduction until my existing prop worked. Much cheaper and easier than changing a prop.?
|
Re: Newbie looking for guidance
Assuming this was a 18hp Atomic??
You could definitely gain by going with a larger prop. Since you cant go much bigger and you wont need much power at all to push this 6 knots its probably not worth it.?
Personally I think a 3kw motor would be plenty for this boat to putt around.? Since there isn't really any penalty in oversizing, I might go with a 10kw. This would match or exceed the performance of the Atomic.?
I would also try and go direct drive. It may overheat at top speed, but you wont have the battery capacity to keep it there long enough to be an issue.?
I typically don't recommend anything other than LFP for boats. I wouldn't be apposed to it here as long as its in a portable, waterproof enclosure. This will help keep the weight down and in turn have a larger capacity capable of pushing 10kw motor.?
Matt Foley? Sunlight Conversions Perpetual Energy, LLC 201-914-0466
On Wednesday, December 28, 2022 at 12:49:33 PM EST, twowheelinguy via groups.io <twowheelinguy@...> wrote:
I was thinking the same thing as Al. If that Atomic 4 is running good why convert?? A4s are super quiet and efficient ICEs. With the exception of using gasoline as its fuel, A4s are awesome and they would definitely be the best way to go 20 kts. But if you have an aversion to gas on a boat , don't want to listen to and smell diesel and don't care of you ever go 20 knots again then that boat looks like it would be an excellent electric boat.?
I'd guess with a solar canopy it could cruise 5 kts just off solar on a sunny day.
If you're sure? electric is the best for you, Thunderstruck is a good place to look for an all inclusive kit for a good price but if you really have a tight budget I'd look at golf cart conversion? kits. I've been running one for 10 years. To say it's a little underpowered is an understatement but it will push the Arc 4 mph on nothing but sunshine and make 5 kits if I suck on the batteries hard. It won't take much to get that boat up to 6 or 7 mph if that's all you want and if you do want to go much faster it won't do it for long unless you spend a fortune on batteries and a lot more on a motor and controller that you won't use most of the time.
Gas or electric though, it's a cool boat.
Capt. Carter Www.shipofimagination.com
On Wed, Dec 28, 2022 at 11:16 AM, 63urban <63urban@...> wrote: But wouldn't that be far less efficient and a little more noise?
Nick
Sent from my Bell Samsung device over Canada's largest network.
-------- Original message -------- From: kurtphone@... Date: 2022-12-28 10:35 a.m. (GMT-05:00) Subject: Re: [electricboats] Newbie looking for guidance
i got my kit from Thunderstruck as well. Two thumbs up! I just changed sprockets/ratios on the gear reduction until my existing prop worked. Much cheaper and easier than changing a prop.?
|
Re: Newbie looking for guidance
I was thinking the same thing as Al. If that Atomic 4 is running good why convert?? A4s are super quiet and efficient ICEs. With the exception of using gasoline as its fuel, A4s are awesome and they would definitely be the best way to go 20 kts. But if you have an aversion to gas on a boat , don't want to listen to and smell diesel and don't care of you ever go 20 knots again then that boat looks like it would be an excellent electric boat.?
I'd guess with a solar canopy it could cruise 5 kts just off solar on a sunny day.
If you're sure? electric is the best for you, Thunderstruck is a good place to look for an all inclusive kit for a good price but if you really have a tight budget I'd look at golf cart conversion? kits. I've been running one for 10 years. To say it's a little underpowered is an understatement but it will push the Arc 4 mph on nothing but sunshine and make 5 kits if I suck on the batteries hard. It won't take much to get that boat up to 6 or 7 mph if that's all you want and if you do want to go much faster it won't do it for long unless you spend a fortune on batteries and a lot more on a motor and controller that you won't use most of the time.
Gas or electric though, it's a cool boat.
Capt. Carter Www.shipofimagination.com
On Wed, Dec 28, 2022 at 11:16 AM, 63urban <63urban@...> wrote: But wouldn't that be far less efficient and a little more noise?
Nick
Sent from my Bell Samsung device over Canada's largest network.
-------- Original message -------- From: kurtphone@... Date: 2022-12-28 10:35 a.m. (GMT-05:00) Subject: Re: [electricboats] Newbie looking for guidance
i got my kit from Thunderstruck as well. Two thumbs up! I just changed sprockets/ratios on the gear reduction until my existing prop worked. Much cheaper and easier than changing a prop.?
|
Re: Newbie looking for guidance
But wouldn't that be far less efficient and a little more noise?
Nick
Sent from my Bell Samsung device over Canada's largest network.
toggle quoted message
Show quoted text
-------- Original message -------- From: kurtphone@... Date: 2022-12-28 10:35 a.m. (GMT-05:00) Subject: Re: [electricboats] Newbie looking for guidance
i got my kit from Thunderstruck as well. Two thumbs up! I just changed sprockets/ratios on the gear reduction until my existing prop worked. Much cheaper and easier than changing a prop.?
|
Re: Newbie looking for guidance
i got my kit from Thunderstruck as well. Two thumbs up!
I just changed sprockets/ratios on the gear reduction until my existing prop worked. Much cheaper and easier than changing a prop.?
|
Re: Newbie looking for guidance
Nicely done! If it were me I would be happy with the current speeds that you are getting, but my boat is electric and the only way it will go that fast is on the trailer. Have fun with your boat. Best Regards Al Hartley
On Tue, Dec 27, 2022 at 10:15 AM Michael Schiller via <captainmike454= [email protected]> wrote: Thunderstruck EV is where my kit came from there is a lot of information on the site. On Dec 27, 2022, at 9:39 AM, Tom@... wrote:
?Hello friends, i just stumbled upon this site and looks like a wealth of information. I built a little crab skiff during Covid, 21’ narrow and pretty light. Power is currently an Atomic 4 gas engine.? It is a tunnel drive and turning a 12”- 3 blade cupped “indigo” prop, specifically designed for A4’s. I believe the prop was meant to allow the A4 to turn up and run at 1400 rpm. the boat currently runs about 14knts wot but is used mostly at 2 to 7 knots which guessing is 500- 1000 rpm. I can only go an inch bigger prop due to tunnel. I guess my question is where does one start picking the components? Can I expect any efficiency with existing prop? thank you for any feedback tom <2EACD22E-788D-44D1-AB1B-1D32B6CF87D1.jpeg> <A1E5DB80-AE76-457C-AE58-48E58F40EC01.jpeg> <162A3583-DB8C-405E-910B-E9814647F6A6.jpeg>
|
Re: Newbie looking for guidance
Thunderstruck EV is where my kit came from there is a lot of information on the site.
toggle quoted message
Show quoted text
On Dec 27, 2022, at 9:39 AM, Tom@... wrote:
?Hello friends, i just stumbled upon this site and looks like a wealth of information. I built a little crab skiff during Covid, 21’ narrow and pretty light. Power is currently an Atomic 4 gas engine. ?It is a tunnel drive and turning a 12”- 3 blade cupped “indigo” prop, specifically designed for A4’s. I believe the prop was meant to allow the A4 to turn up and run at 1400 rpm. the boat currently runs about 14knts wot but is used mostly at 2 to 7 knots which guessing is 500- 1000 rpm. I can only go an inch bigger prop due to tunnel. I guess my question is where does one start picking the components? Can I expect any efficiency with existing prop? thank you for any feedback tom <2EACD22E-788D-44D1-AB1B-1D32B6CF87D1.jpeg> <A1E5DB80-AE76-457C-AE58-48E58F40EC01.jpeg> <162A3583-DB8C-405E-910B-E9814647F6A6.jpeg>
|
Newbie looking for guidance
Hello friends,
i just stumbled upon this site and looks like a wealth of information.
I built a little crab skiff during Covid, 21’ narrow and pretty light. Power is currently an Atomic 4 gas engine. ?It is a tunnel drive and turning a 12”- 3 blade cupped “indigo” prop, specifically designed for A4’s. I believe the prop was meant to allow the A4 to turn up and run at 1400 rpm.
the boat currently runs about 14knts wot but is used mostly at 2 to 7 knots which guessing is 500- 1000 rpm.
I can only go an inch bigger prop due to tunnel.
I guess my question is where does one start picking the components?
Can I expect any efficiency with existing prop?
thank you for any feedback
tom
|
Re: Li-ion battery designer commentary
I've heard good things about NorthStar batteries, and I've used the Trojan "carbon infused" batteries but I wasn't that impressed. Sure, they worked a lot better, but they still don't hold a candle to Lithium chemistry. And carbon infused lead batteries are a lot more expensive so that cancels out any cost advantage they might offer.? ?
The problem with lead chemistry is not it's capacity to store energy, it actually provides a pretty good value for that. The problem is you lose your ass putting the energy in and taking it out, especially if you want to do it in a hurry. If you have a system where you can charge slowly and only do low current draws with low depth of discharge, you could have argued that lead was a better value than lithium until recently. But now that you can buy a ready to use kWhr of lithium storage capacity for $250, lead has just about lost any price advantage it had and once it hit's $150/kWhr it will pretty much be game over for the lead battery industry. I don't think lead will ever completely be dead but it will soon be relegated to only very specialized applications imo.?
I'm on a cruise right now running my new lithium batteries hard for the first time and I can state UNEQUIVELENTLY they are definitely in another league than ANY lead batteries I've ever used or heard of and I've cruised the Arc over 5000 miles using various lead batteries over the last 12 years. As a long time holdout for using lead acid chemistry, I have to agree with Elon Musk now when he said, "lead sucks".?
You can still debate the cost benefit ratio of lead for some specialty applications but comparing the performance of lead to lithium is like comparing little league baseball to the major league.? Lithium is that much better, imo.
Capt. Carter www.shipofimagination.com
On Saturday, December 10, 2022 at 06:57:55 AM EST, F. Neil <fneilss@...> wrote:
At >60 pounds per kWh, and limited 50% depth of discharge (for maximum lifespan), these Northstar carbon lead batteries are not really in the same class as Lifepo4 batteries for applications where energy density is an issue...?
|
cpcanoesailor
Reuben Trane