Re: Ang.:[electricboats] Finally Starting The Build

I suppose you could do the safety wire on the terminal studs or nuts on the bus bar between adjacent cells.  Or you could put a hole in the bus bar as the anchor point for the wire.  Care would be required when working with this floppy wire over the battery cell terminals (as it would be working with anything over the cell terminals).   

I have not seen these 6mm studs with holes for wire but if the studs were brass it would be easy enough to drill them with a little jig on a drill press.  Same for the copper buss bars.  





Dan Pfeiffer

 

On 2021-08-22 11:49 pm, Dan Pfeiffer wrote:

How exactly does the safety wire go on the battery terminal studs or nuts?  What does it anchor to?  It cannot go to any other battery terminal because that would be a short. 

Can you give a link to some of the "Tons of info on the 'net on how you do it."

I do safety wire with the set screws on my propeller shaft flanges.  But they are not separate electrical conductors.   There is no concern about short circuits. 


Dan Pfeiffer

On 2021-08-22 9:08 pm, Carsten via groups.io wrote:

I'm all in for brass bolts and nuts !

 

As an aircraft mech (hobby), I would do like this :

If you want all the contact you can get, avoid Loctite and use safety wire (stainless soft wire, not the one from your shelves in your home workshop).

Drill holes in the bolt heads, and follow the general pratices for this kind of work, or you might end up doing worse than doing nothing at all.

Tons of info on the 'net on how you do it.

Remember to buy a safety wire twister, saves a lot of hand work, and the twists looks nicer too.

That will work, and you can always unscrew your bolts without any hazzle.

 

På fre., den 20. aug. 2021 klokken 9:31, Randy Cain

<randylcain@gmail.com> skrev:

Finally starting to build the first of four 32s batteries for my boat. These are EVE 280Ah LiFePO4 prismatics. I ordered 134 of them just as the pandemic was starting. There will be 4 battery banks of 32 cells each (one in each of the two bows and one in each of the two sterns) for a total of around 114kwh of energy storage. Even after 18 months in their boxes, they are all still within +-0.001 volts of each other (3.295) and within +-0.01 milliohms (0.18 mohm internal resistance). Next step is Locktite and torque wrench to set the 40mm grub screw terminal posts.

Re: Ang.:[electricboats] Finally Starting The Build

How exactly does the safety wire go on the battery terminal studs or nuts?  What does it anchor to?  It cannot go to any other battery terminal because that would be a short. 

Can you give a link to some of the "Tons of info on the 'net on how you do it."

I do safety wire with the set screws on my propeller shaft flanges.  But they are not separate electrical conductors.   There is no concern about short circuits. 


Dan Pfeiffer

On 2021-08-22 9:08 pm, Carsten via groups.io wrote:

I'm all in for brass bolts and nuts !

 

As an aircraft mech (hobby), I would do like this :

If you want all the contact you can get, avoid Loctite and use safety wire (stainless soft wire, not the one from your shelves in your home workshop).

Drill holes in the bolt heads, and follow the general pratices for this kind of work, or you might end up doing worse than doing nothing at all.

Tons of info on the 'net on how you do it.

Remember to buy a safety wire twister, saves a lot of hand work, and the twists looks nicer too.

That will work, and you can always unscrew your bolts without any hazzle.

 

På fre., den 20. aug. 2021 klokken 9:31, Randy Cain

<randylcain@gmail.com> skrev:

Finally starting to build the first of four 32s batteries for my boat. These are EVE 280Ah LiFePO4 prismatics. I ordered 134 of them just as the pandemic was starting. There will be 4 battery banks of 32 cells each (one in each of the two bows and one in each of the two sterns) for a total of around 114kwh of energy storage. Even after 18 months in their boxes, they are all still within +-0.001 volts of each other (3.295) and within +-0.01 milliohms (0.18 mohm internal resistance). Next step is Locktite and torque wrench to set the 40mm grub screw terminal posts.

Ang.:[electricboats] Finally Starting The Build

I'm all in for brass bolts and nuts !

As an aircraft mech (hobby), I would do like this :

If you want all the contact you can get, avoid Loctite and use safety wire (stainless soft wire, not the one from your shelves in your home workshop).

Drill holes in the bolt heads, and follow the general pratices for this kind of work, or you might end up doing worse than doing nothing at all.

Tons of info on the 'net on how you do it.

Remember to buy a safety wire twister, saves a lot of hand work, and the twists looks nicer too.

That will work, and you can always unscrew your bolts without any hazzle.

På fre., den 20. aug. 2021 klokken 9:31, Randy Cain

<randylcain@gmail.com> skrev:

Finally starting to build the first of four 32s batteries for my boat. These are EVE 280Ah LiFePO4 prismatics. I ordered 134 of them just as the pandemic was starting. There will be 4 battery banks of 32 cells each (one in each of the two bows and one in each of the two sterns) for a total of around 114kwh of energy storage. Even after 18 months in their boxes, they are all still within +-0.001 volts of each other (3.295) and within +-0.01 milliohms (0.18 mohm internal resistance). Next step is Locktite and torque wrench to set the 40mm grub screw terminal posts.

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[electricboats] Relative priorities in choosing LiFePO batteries for bank?

Dear group members - I will have to commit to the actual battery bank purchase for my boat build sometime in the next few months, and as a complete newbie to electric boating I struggle to decide priorities. Can the Hive mind help me out here?

My boat will be a 34ft/10m, 5 ton dry weight catamaran - the first of its line to be commissioned without a mast and sailing rig as a slow trawler. Propulsion will be via twin 10kW pod motors at 48V. There will be approx 4kWp solar and a main/propulsion battery bank of around 32kWh alongside a house bank of around 5.5kWh. I will be buying branded batteries for warranty and insurance reasons.

I will also be running an 11ft dinghy tender on electric propulsion, and hope to use the same (or at least same brand) 5.5kWh battery/-ies for this as for the mothership.

It would be very helpful if members could rank the following considerations in priority terms if they were in my position:

* Expense (£/kWh) - possibly including any order volume related discount
* Power charge density (kWh/kg)
* Luggability (ie. <40kg per unit) in case of malfunctions
* Warranty duration
* Water ingress protection rating (IP67 or less)
* Advertised life expectancy (discharge cycles to 80%SOC)
* [any other criterion members might consider important]

Would members advocate buying European/North American labelled batteries over Chinese/HK labels in case a full blown trade war erupts in the years ahead?

If the above considerations have been previously discussed or written about I would be grateful for links to relevant forum/blog posts or publications!

Many thanks for your advice,
Kai


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Ang.:Re: [electricboats] Finally Starting The Build

Guys, please post a few photos of your setups  ;-)

"A photo says more than a thousand words".

Cheers,

Carsten

På søn., den 22. aug. 2021 klokken 19:16, Randy Cain

<randylcain@gmail.com> skrev:

The loctite is only for thread locking to prevent turning and any chance of galling. I insulate the post threads that protrude from the terminal up to the point where the nut covers them because that's where they could make contact with the lugs and bars. I also insulate between the nut and the lug or bar below it. I 3d print a one-piece sleeve+washer combination part for that insulation task out of PETG plastic.

Re: [electricboats] Finally Starting The Build

The loctite is only for thread locking to prevent turning and any chance of galling. I insulate the post threads that protrude from the terminal up to the point where the nut covers them because that's where they could make contact with the lugs and bars. I also insulate between the nut and the lug or bar below it. I 3d print a one-piece sleeve+washer combination part for that insulation task out of PETG plastic.

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Re: [electricboats] Finally Starting The Build

That's an interesting point about resistance in the studs on terminal that I had not considered.  It seems like a pretty unlikely problem but I will run it by my "electrical engineering department".  Does the locktite provide a complete and reliable electrical insulator between the threads of the SS stud and the aluminum?  If not could that create a potentially higher resistance and higher temperatures in your failure scenario?  How much is the contact area between the bus bar and the battery contact flat reduced by the plastic sleeve you used?   I see buss bars from Blue Seas that have SS fasteners into the copper buss bar.  
https://www.bluesea.com/products/2127/MaxiBus_250A_BusBar_-_Four_5_16in-18_Studs

Is the concern the different conductivity of the SS?  Brass studs could be used rather than SS.  Certainly the strength is OK considering the torque specs?

McMaster has these M6x20 set screws in brass
https://www.mcmaster.com/93038A149/
And these brass nuts:
https://www.mcmaster.com/90690A047/



Dan Pfeiffer

 

On 2021-08-21 6:49 am, Randy Cain wrote:

That's a good looking build! It probably won't be an issue but passing current through the SS studs and nuts (should the low resistance path directly between terminal and lug fail) will allow the battery to continue working (at a lower voltage and with a higher current draw) resulting in a very, very hot fitting. Generally, it's better to have a battery stop working than to have it work and become a possible source of a fire. IMHO fasteners should be insulated to prevent ever becoming a current-carrying component.

Re: [electricboats] Finally Starting The Build

That's a good looking build! It probably won't be an issue but passing current through the SS studs and nuts (should the low resistance path directly between terminal and lug fail) will allow the battery to continue working (at a lower voltage and with a higher current draw) resulting in a very, very hot fitting. Generally, it's better to have a battery stop working than to have it work and become a possible source of a fire. IMHO fasteners should be insulated to prevent ever becoming a current-carrying component.

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Re: [electricboats] Lifepo4 Batteries available and ready to ship from US

Just to close the loop on this part:

Here is a link to the spec sheet:

https://static1.squarespace.com/static/6050cbc3ab828124470dd6da/t/61200a5c5ad38c5553ca1034/1629489757267/48v200ahPowerwallSpec.pdf

���which has a little more info on the the way they reached that number:

��� After Normal charge���discharge @0.5C current to the end of discharge voltage. Repeat above process until discharge capacity reduce to 80% of initial value.���

On Aug 20, 2021, at 08:41, Dan Pfeiffer <dan@pfeiffer.net> wrote:

���

Yes, I agree with your reasoning.  I just wanted to know where the 6000 cycles to 80% figure came from.   I see Ryan is looking into that.  Thanks Ryan.  And I thought you had been using the Eve or Lishen cells?  No more?


I have about a 4 mile round trip to make from my dock out to open water and back.  So far I am using about 20% of my usable capacity each time I go.   I have a 13,400Wh battery and at about 80% DOD the usable capacity is about 11,000 Wh.  I am using about 2200 Wh each trip out and back.   At this rate for even 1000 full charge cycles I would be looking at 5000 trips out and back or every day for 14 years.   For my typical season I get out 60 to 80 days.   At 80 days the battery should last 62 years.  I expect other issues will shorten that significantly.  And better technology may supplant my battery long before it's end of life.   Hopefully I'll be around and sailing long enough to collect some data. 

I am working on collecting more and better data now that I have the shunt meter installed.  I am trying to get my wind and boat speed (in water) integrated into the data collection.  Headwinds make a significant difference on consumption.  Waves too of course.  I hope to have some figures on all that soon.

Boat Details
Pearson 10M
33' LOA, 28.3'LWL, 12,500lbs
ME1616 motor, Sevcon4
48V LiFePo4 280AH (from Eve cells)


Dan Pfeiffer

On 2021-08-20 10:12 am, Myles Twete wrote:

Reminder: We are talking about electric "boats" here.

 

Unless you are adding fast charge capability to your boat (and marinas!), the most you will be charging is 360 cycles per year.  It would require 10 years of daily use and recharge to reach 3600 cycles.

 

I would venture to guess that most folks won't recharge even weekly, or with even larger packs and less usage, monthly or quarterly.  So typically you're looking at between 8 and 20 charge cycles per year.  Even 1000 charge cycles requires 100 years of use!

Given that, and until we have waterways riddled with quick charge stations, it's ridiculous and a waste of bandwidth here to talk about charge cycle life for boat packs.

 

Just my opinion, but based on 8+ years experience now running with lithium and charging at maybe 6-10x per year.  My boat will sink and I will be long dead before my batteries' charge cycle life becomes a limiting factor.

 

-mt

 

From: electricboats@groups.io [mailto:electricboats@groups.io] On Behalf Of Dan Pfeiffer
Sent: Friday, August 20, 2021 7:47 AM
To: electricboats@groups.io
Subject: Re: [electricboats] Lifepo4 Batteries available and ready to ship from US

 

Ryan,

What cells are you using?  Where does the 6000 cycles to 80% figure come from?  It looks like about 3750 at 80% in the cycle life chart in this document for the EVE 280AH cells.  I would expect the 200AH cells to be similar? 

http://www.dcmax.com.tw/LF280(3.2V280Ah).pdf


Dan Pfeiffer

 

On 2021-08-20 9:34 am, Ryan Sweet wrote:

One more thing: I will warranty these stateside with spares, for five years. I fully expect them to last the lifetime of your boat (6000 cycles to 80% capacity), but nonetheless I am reserving spares for warranty issues just in case, and you would not have to wait for them to ship from China. 

 

Re: [electricboats] Finally Starting The Build

I used these screws from McMaster Carr:
https://www.mcmaster.com/92605A134/

They have a flat tip and I thought that would help get more engagement of the threads.  I did not use locktite.  I applied contact grease to the threads and all contact surfaces of the battery terminals and bus bars.  I considered the threaded studs contact surfaces.  I made my bus bars from 3/4" x 1/4" copper bar and the holes are much closer to 6mm.  One hole is a tight clearance fit for the stud the other is slightly elongated. I figured every square mm of contact was useful in a high current application like this.  And I thought locktite would act as an insulator and inhibit contact between the screw and the threads though it might improve the hold of the studs and that could be more important? 

I torqued the studs to spec with a torque limiting driver and used SS nuts to hold the bus bars down.  They were the type with a serrated flange but I can't find that order reference right now.   When I tightened the nuts holding my bus bars I held the stud from turning as I tightened down the nuts.  I connected the BMS leads to the bus bars with separate 10-24 brass screws in threaded holes in the bus bars rather than ring terminals under the nuts holding the bus bars to the studs.  I didn't want anything adding to the task of holding the bus bars to the studs.  

I don't know how much strength there is in the terminal threads on these batteries but I am sure they would be easy to strip.  But I seem to recall reading somewhere that the real issue was inside the cell where the pouches connect to the terminal or the cross bar that the terminal attaches to.  The torque spec may have to do with protecting that part not the threads in the holes.    I can't confirm that this was an issue at all.  I just recall seeing something about it.  It could have been speculation. 
 

Dan Pfeiffer

 

On 2021-08-20 1:57 pm, Randy Cain wrote:

I'm using steel m6 grub screws from Monsterbolts (both ebay and amazon) torqued to 4Nm with loctite 242. I'll then slip a plastic sleeve over it since the lugs have 8mm or 9mm holes and don't need to contact the stud anyway.

Re: [electricboats] Finally Starting The Build

I'm using steel m6 grub screws from Monsterbolts (both ebay and amazon) torqued to 4Nm with loctite 242. I'll then slip a plastic sleeve over it since the lugs have 8mm or 9mm holes and don't need to contact the stud anyway.

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Re: [electricboats] Lifepo4 Batteries available and ready to ship from US

Let's take queries of that nature off-list. Can use the "reply-to-sender" links below or email ryan@pacificalgorithms.com.  

Fred - I'll email you directly.  

Regards,

-Ryan

On Aug 20, 2021, at 10:54 AM, fred jelich <freddyj408@gmail.com> wrote:

What is the cost for 48volt pack? I only need 50ah. 

On Fri, Aug 20, 2021, 9:34 AM Ryan Sweet <ryan@ryansweet.org> wrote:

One more thing: I will warranty these stateside with spares, for five years. I fully expect them to last the lifetime of your boat (6000 cycles to 80% capacity), but nonetheless I am reserving spares for warranty issues just in case, and you would not have to wait for them to ship from China. 

On Aug 19, 2021, at 20:23, Ryan Sweet via groups.io <ryan=ryansweet.org@groups.io> wrote:



Ok, thank you Jeff… well then to simplify things, here is the site again:

https://www.pacificalgorithms.com/

Of course if you have questions drop me a line… 

If you live in the Puget Sound region, I may be able to deliver them or meet you for pickup.

Note that the inverters already sold out. Also in case it isn't clear, the powerwalls can be mounted laying flat, like any other lifepo4 they don't require a specific orientation. 

On Aug 19, 2021, at 19:51, reesekc <kcr@kcrproducts.com> wrote:



I have a Hughes 35.5 that I power with a Thunderstruck 10kw kit. I'm presently using 4 x 100 amp 13.2v lithium batteries to power the system at 48v, and used a DC to DC converter (48 >12) for "house power". I would be interested in having more battery storage.

On Thu, Aug 19, 2021 at 7:30 PM Ryan Sweet <ryan@ryansweet.org> wrote:

… I tried to look to find out what the policy here is on sharing commercial ventures…. I'm not finding the previous thread where that was discussed.  In any case, right now my setup is running more like a co-op since I'm passing goods on at basically the cost to me after customs, taxes, etc.

So - if you are interested in lifepo4 powerwalls (200ah each, each one has a C rate of 200a, hence will power an me 10kw motor), I have inventory finally and thus can ship to you from the US. Drop me a line and I can point you to my website for more info.

Regards,
-Ryan

Re: [electricboats] Lifepo4 Batteries available and ready to ship from US

What is the cost for 48volt pack? I only need 50ah. 

On Fri, Aug 20, 2021, 9:34 AM Ryan Sweet <ryan@ryansweet.org> wrote:

One more thing: I will warranty these stateside with spares, for five years. I fully expect them to last the lifetime of your boat (6000 cycles to 80% capacity), but nonetheless I am reserving spares for warranty issues just in case, and you would not have to wait for them to ship from China. 

On Aug 19, 2021, at 20:23, Ryan Sweet via groups.io <ryan=ryansweet.org@groups.io> wrote:



Ok, thank you Jeff… well then to simplify things, here is the site again:

https://www.pacificalgorithms.com/

Of course if you have questions drop me a line… 

If you live in the Puget Sound region, I may be able to deliver them or meet you for pickup.

Note that the inverters already sold out. Also in case it isn't clear, the powerwalls can be mounted laying flat, like any other lifepo4 they don't require a specific orientation. 

On Aug 19, 2021, at 19:51, reesekc <kcr@kcrproducts.com> wrote:



I have a Hughes 35.5 that I power with a Thunderstruck 10kw kit. I'm presently using 4 x 100 amp 13.2v lithium batteries to power the system at 48v, and used a DC to DC converter (48 >12) for "house power". I would be interested in having more battery storage.

On Thu, Aug 19, 2021 at 7:30 PM Ryan Sweet <ryan@ryansweet.org> wrote:

… I tried to look to find out what the policy here is on sharing commercial ventures…. I'm not finding the previous thread where that was discussed.  In any case, right now my setup is running more like a co-op since I'm passing goods on at basically the cost to me after customs, taxes, etc.

So - if you are interested in lifepo4 powerwalls (200ah each, each one has a C rate of 200a, hence will power an me 10kw motor), I have inventory finally and thus can ship to you from the US. Drop me a line and I can point you to my website for more info.

Regards,
-Ryan

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Re: [electricboats] Lifepo4 Batteries available and ready to ship from US

I am just under 2 miles from the open water.  But I use the time it takes to get out (25 min) to get the boat ready to sail.  In the time it takes to get in I am furling and covering and getting dock lines/fenders ready.  When the wind is blowing like stink I can get out and back in with relative ease.  I was out in 15-20 a little bit ago and it was blowing 4 at the dock back up the river.  So there are pros/cons.  I am happy to live with the time for the protection.  

 

Dan Pfeiffer

On 2021-08-20 10:53 am, Ryan Sweet wrote:

To answer your question - wasn't me - must have been someone else.  I have also worked with Felicty Solar, and will stock some of their powerwalls again, but I worked with them to upgrade the BMS C rate and it will take some time before those models are ready. 

 

4 miles!  I feel lucky to have a short 800 yards to loop around the breakwater!  I've been practicing whether I can sail it - its easy enough to sail *in*, usually with just the mizzen, but getting out has proven beyond my ability most of the time, as the wind usually is blowing straight into my slip. ;-)

On Aug 20, 2021, at 8:41 AM, Dan Pfeiffer <dan@pfeiffer.net> wrote:

Yes, I agree with your reasoning.  I just wanted to know where the 6000 cycles to 80% figure came from.   I see Ryan is looking into that.  Thanks Ryan.  And I thought you had been using the Eve or Lishen cells?  No more?


I have about a 4 mile round trip to make from my dock out to open water and back.  So far I am using about 20% of my usable capacity each time I go.   I have a 13,400Wh battery and at about 80% DOD the usable capacity is about 11,000 Wh.  I am using about 2200 Wh each trip out and back.   At this rate for even 1000 full charge cycles I would be looking at 5000 trips out and back or every day for 14 years.   For my typical season I get out 60 to 80 days.   At 80 days the battery should last 62 years.  I expect other issues will shorten that significantly.  And better technology may supplant my battery long before it's end of life.   Hopefully I'll be around and sailing long enough to collect some data.  

I am working on collecting more and better data now that I have the shunt meter installed.  I am trying to get my wind and boat speed (in water) integrated into the data collection.  Headwinds make a significant difference on consumption.  Waves too of course.  I hope to have some figures on all that soon.

Boat Details
Pearson 10M
33' LOA, 28.3'LWL, 12,500lbs
ME1616 motor, Sevcon4 
48V LiFePo4 280AH (from Eve cells)


Dan Pfeiffer

On 2021-08-20 10:12 am, Myles Twete wrote:

Reminder: We are talking about electric "boats" here.

 

Unless you are adding fast charge capability to your boat (and marinas!), the most you will be charging is 360 cycles per year.  It would require 10 years of daily use and recharge to reach 3600 cycles.

 

I would venture to guess that most folks won't recharge even weekly, or with even larger packs and less usage, monthly or quarterly.  So typically you're looking at between 8 and 20 charge cycles per year.  Even 1000 charge cycles requires 100 years of use!

Given that, and until we have waterways riddled with quick charge stations, it's ridiculous and a waste of bandwidth here to talk about charge cycle life for boat packs.

 

Just my opinion, but based on 8+ years experience now running with lithium and charging at maybe 6-10x per year.  My boat will sink and I will be long dead before my batteries' charge cycle life becomes a limiting factor.

 

-mt

 

From: electricboats@groups.io [mailto:electricboats@groups.io] On Behalf Of Dan Pfeiffer
Sent: Friday, August 20, 2021 7:47 AM
To: electricboats@groups.io
Subject: Re: [electricboats] Lifepo4 Batteries available and ready to ship from US

 

Ryan,

What cells are you using?  Where does the 6000 cycles to 80% figure come from?  It looks like about 3750 at 80% in the cycle life chart in this document for the EVE 280AH cells.  I would expect the 200AH cells to be similar?  

http://www.dcmax.com.tw/LF280(3.2V280Ah).pdf


Dan Pfeiffer

 

On 2021-08-20 9:34 am, Ryan Sweet wrote:

One more thing: I will warranty these stateside with spares, for five years. I fully expect them to last the lifetime of your boat (6000 cycles to 80% capacity), but nonetheless I am reserving spares for warranty issues just in case, and you would not have to wait for them to ship from China. 

 

Re: [electricboats] Lifepo4 Batteries available and ready to ship from US

To answer your question - wasn't me - must have been someone else.  I have also worked with Felicty Solar, and will stock some of their powerwalls again, but I worked with them to upgrade the BMS C rate and it will take some time before those models are ready. 

4 miles!  I feel lucky to have a short 800 yards to loop around the breakwater!  I've been practicing whether I can sail it - its easy enough to sail *in*, usually with just the mizzen, but getting out has proven beyond my ability most of the time, as the wind usually is blowing straight into my slip. ;-)

On Aug 20, 2021, at 8:41 AM, Dan Pfeiffer <dan@pfeiffer.net> wrote:

Yes, I agree with your reasoning.  I just wanted to know where the 6000 cycles to 80% figure came from.   I see Ryan is looking into that.  Thanks Ryan.  And I thought you had been using the Eve or Lishen cells?  No more?


I have about a 4 mile round trip to make from my dock out to open water and back.  So far I am using about 20% of my usable capacity each time I go.   I have a 13,400Wh battery and at about 80% DOD the usable capacity is about 11,000 Wh.  I am using about 2200 Wh each trip out and back.   At this rate for even 1000 full charge cycles I would be looking at 5000 trips out and back or every day for 14 years.   For my typical season I get out 60 to 80 days.   At 80 days the battery should last 62 years.  I expect other issues will shorten that significantly.  And better technology may supplant my battery long before it's end of life.   Hopefully I'll be around and sailing long enough to collect some data.  

I am working on collecting more and better data now that I have the shunt meter installed.  I am trying to get my wind and boat speed (in water) integrated into the data collection.  Headwinds make a significant difference on consumption.  Waves too of course.  I hope to have some figures on all that soon.

Boat Details
Pearson 10M
33' LOA, 28.3'LWL, 12,500lbs
ME1616 motor, Sevcon4 
48V LiFePo4 280AH (from Eve cells)


Dan Pfeiffer

On 2021-08-20 10:12 am, Myles Twete wrote:

Reminder: We are talking about electric "boats" here.

 

Unless you are adding fast charge capability to your boat (and marinas!), the most you will be charging is 360 cycles per year.  It would require 10 years of daily use and recharge to reach 3600 cycles.

 

I would venture to guess that most folks won't recharge even weekly, or with even larger packs and less usage, monthly or quarterly.  So typically you're looking at between 8 and 20 charge cycles per year.  Even 1000 charge cycles requires 100 years of use!

Given that, and until we have waterways riddled with quick charge stations, it's ridiculous and a waste of bandwidth here to talk about charge cycle life for boat packs.

 

Just my opinion, but based on 8+ years experience now running with lithium and charging at maybe 6-10x per year.  My boat will sink and I will be long dead before my batteries' charge cycle life becomes a limiting factor.

 

-mt

 

From: electricboats@groups.io [mailto:electricboats@groups.io] On Behalf Of Dan Pfeiffer
Sent: Friday, August 20, 2021 7:47 AM
To: electricboats@groups.io
Subject: Re: [electricboats] Lifepo4 Batteries available and ready to ship from US

 

Ryan,

What cells are you using?  Where does the 6000 cycles to 80% figure come from?  It looks like about 3750 at 80% in the cycle life chart in this document for the EVE 280AH cells.  I would expect the 200AH cells to be similar?  

http://www.dcmax.com.tw/LF280(3.2V280Ah).pdf


Dan Pfeiffer

 

On 2021-08-20 9:34 am, Ryan Sweet wrote:

One more thing: I will warranty these stateside with spares, for five years. I fully expect them to last the lifetime of your boat (6000 cycles to 80% capacity), but nonetheless I am reserving spares for warranty issues just in case, and you would not have to wait for them to ship from China. 

 

Re: [electricboats] Lifepo4 Batteries available and ready to ship from US

Yes, I agree with your reasoning.  I just wanted to know where the 6000 cycles to 80% figure came from.   I see Ryan is looking into that.  Thanks Ryan.  And I thought you had been using the Eve or Lishen cells?  No more?


I have about a 4 mile round trip to make from my dock out to open water and back.  So far I am using about 20% of my usable capacity each time I go.   I have a 13,400Wh battery and at about 80% DOD the usable capacity is about 11,000 Wh.  I am using about 2200 Wh each trip out and back.   At this rate for even 1000 full charge cycles I would be looking at 5000 trips out and back or every day for 14 years.   For my typical season I get out 60 to 80 days.   At 80 days the battery should last 62 years.  I expect other issues will shorten that significantly.  And better technology may supplant my battery long before it's end of life.   Hopefully I'll be around and sailing long enough to collect some data. 

I am working on collecting more and better data now that I have the shunt meter installed.  I am trying to get my wind and boat speed (in water) integrated into the data collection.  Headwinds make a significant difference on consumption.  Waves too of course.  I hope to have some figures on all that soon.

Boat Details
Pearson 10M
33' LOA, 28.3'LWL, 12,500lbs
ME1616 motor, Sevcon4
48V LiFePo4 280AH (from Eve cells)


Dan Pfeiffer

On 2021-08-20 10:12 am, Myles Twete wrote:

Reminder: We are talking about electric "boats" here.

 

Unless you are adding fast charge capability to your boat (and marinas!), the most you will be charging is 360 cycles per year.  It would require 10 years of daily use and recharge to reach 3600 cycles.

 

I would venture to guess that most folks won't recharge even weekly, or with even larger packs and less usage, monthly or quarterly.  So typically you're looking at between 8 and 20 charge cycles per year.  Even 1000 charge cycles requires 100 years of use!

Given that, and until we have waterways riddled with quick charge stations, it's ridiculous and a waste of bandwidth here to talk about charge cycle life for boat packs.

 

Just my opinion, but based on 8+ years experience now running with lithium and charging at maybe 6-10x per year.  My boat will sink and I will be long dead before my batteries' charge cycle life becomes a limiting factor.

 

-mt

 

From: electricboats@groups.io [mailto:electricboats@groups.io] On Behalf Of Dan Pfeiffer
Sent: Friday, August 20, 2021 7:47 AM
To: electricboats@groups.io
Subject: Re: [electricboats] Lifepo4 Batteries available and ready to ship from US

 

Ryan,

What cells are you using?  Where does the 6000 cycles to 80% figure come from?  It looks like about 3750 at 80% in the cycle life chart in this document for the EVE 280AH cells.  I would expect the 200AH cells to be similar? 

http://www.dcmax.com.tw/LF280(3.2V280Ah).pdf


Dan Pfeiffer

 

On 2021-08-20 9:34 am, Ryan Sweet wrote:

One more thing: I will warranty these stateside with spares, for five years. I fully expect them to last the lifetime of your boat (6000 cycles to 80% capacity), but nonetheless I am reserving spares for warranty issues just in case, and you would not have to wait for them to ship from China. 

 

_._,_._,_

Re: [electricboats] Lifepo4 Batteries available and ready to ship from US

Hi Dan,

The cells are made by Rosen Solar.  They don't sell bare cells however - they tell me there is too much demand for the powerwalls and they prefer to focus on that. 

I have just now sent an inquiry to ask more about the testing procedure for getting the 6000 cycle number - I remember discussing it with them but not sure I ever saw the details on the methodology. 

Regards,

-Ryan 

On Aug 20, 2021, at 7:47 AM, Dan Pfeiffer <dan@pfeiffer.net> wrote:

Ryan,

What cells are you using?  Where does the 6000 cycles to 80% figure come from?  It looks like about 3750 at 80% in the cycle life chart in this document for the EVE 280AH cells.  I would expect the 200AH cells to be similar? 

http://www.dcmax.com.tw/LF280(3.2V280Ah).pdf


Dan Pfeiffer

 

On 2021-08-20 9:34 am, Ryan Sweet wrote:

One more thing: I will warranty these stateside with spares, for five years. I fully expect them to last the lifetime of your boat (6000 cycles to 80% capacity), but nonetheless I am reserving spares for warranty issues just in case, and you would not have to wait for them to ship from China. 

On Aug 19, 2021, at 20:23, Ryan Sweet via groups.io <ryan=ryansweet.org@groups.io> wrote:

Ok, thank you Jeff... well then to simplify things, here is the site again:

 

https://www.pacificalgorithms.com/

 

Of course if you have questions drop me a line... 

 

If you live in the Puget Sound region, I may be able to deliver them or meet you for pickup.

 

Note that the inverters already sold out. Also in case it isn't clear, the powerwalls can be mounted laying flat, like any other lifepo4 they don't require a specific orientation. 

On Aug 19, 2021, at 19:51, reesekc <kcr@kcrproducts.com> wrote:

I have a Hughes 35.5 that I power with a Thunderstruck 10kw kit. I'm presently using 4 x 100 amp 13.2v lithium batteries to power the system at 48v, and used a DC to DC converter (48 >12) for "house power". I would be interested in having more battery storage.

On Thu, Aug 19, 2021 at 7:30 PM Ryan Sweet <ryan@ryansweet.org> wrote:

... I tried to look to find out what the policy here is on sharing commercial ventures.... I'm not finding the previous thread where that was discussed.  In any case, right now my setup is running more like a co-op since I'm passing goods on at basically the cost to me after customs, taxes, etc.

So - if you are interested in lifepo4 powerwalls (200ah each, each one has a C rate of 200a, hence will power an me 10kw motor), I have inventory finally and thus can ship to you from the US. Drop me a line and I can point you to my website for more info.

Regards,
-Ryan

Re: [electricboats] Lifepo4 Batteries available and ready to ship from US

Reminder: We are talking about electric "boats" here.

 

Unless you are adding fast charge capability to your boat (and marinas!), the most you will be charging is 360 cycles per year.  It would require 10 years of daily use and recharge to reach 3600 cycles.

 

I would venture to guess that most folks won't recharge even weekly, or with even larger packs and less usage, monthly or quarterly.  So typically you're looking at between 8 and 20 charge cycles per year.  Even 1000 charge cycles requires 100 years of use!

Given that, and until we have waterways riddled with quick charge stations, it's ridiculous and a waste of bandwidth here to talk about charge cycle life for boat packs.

 

Just my opinion, but based on 8+ years experience now running with lithium and charging at maybe 6-10x per year.  My boat will sink and I will be long dead before my batteries' charge cycle life becomes a limiting factor.

 

-mt

From: electricboats@groups.io [mailto:electricboats@groups.io] On Behalf Of Dan Pfeiffer
Sent: Friday, August 20, 2021 7:47 AM
To: electricboats@groups.io
Subject: Re: [electricboats] Lifepo4 Batteries available and ready to ship from US

 

Ryan,

What cells are you using?  Where does the 6000 cycles to 80% figure come from?  It looks like about 3750 at 80% in the cycle life chart in this document for the EVE 280AH cells.  I would expect the 200AH cells to be similar? 

http://www.dcmax.com.tw/LF280(3.2V280Ah).pdf


Dan Pfeiffer

 

On 2021-08-20 9:34 am, Ryan Sweet wrote:

One more thing: I will warranty these stateside with spares, for five years. I fully expect them to last the lifetime of your boat (6000 cycles to 80% capacity), but nonetheless I am reserving spares for warranty issues just in case, and you would not have to wait for them to ship from China. 

On Aug 19, 2021, at 20:23, Ryan Sweet via groups.io <ryan=ryansweet.org@groups.io> wrote:

Ok, thank you Jeff... well then to simplify things, here is the site again:

 

https://www.pacificalgorithms.com/

 

Of course if you have questions drop me a line... 

 

If you live in the Puget Sound region, I may be able to deliver them or meet you for pickup.

 

Note that the inverters already sold out. Also in case it isn't clear, the powerwalls can be mounted laying flat, like any other lifepo4 they don't require a specific orientation. 

On Aug 19, 2021, at 19:51, reesekc <kcr@kcrproducts.com> wrote:

I have a Hughes 35.5 that I power with a Thunderstruck 10kw kit. I'm presently using 4 x 100 amp 13.2v lithium batteries to power the system at 48v, and used a DC to DC converter (48 >12) for "house power". I would be interested in having more battery storage.

 

On Thu, Aug 19, 2021 at 7:30 PM Ryan Sweet <ryan@ryansweet.org> wrote:

... I tried to look to find out what the policy here is on sharing commercial ventures.... I'm not finding the previous thread where that was discussed.  In any case, right now my setup is running more like a co-op since I'm passing goods on at basically the cost to me after customs, taxes, etc.

So - if you are interested in lifepo4 powerwalls (200ah each, each one has a C rate of 200a, hence will power an me 10kw motor), I have inventory finally and thus can ship to you from the US. Drop me a line and I can point you to my website for more info.

Regards,
-Ryan

Re: [electricboats] Lifepo4 Batteries available and ready to ship from US

Ugh…

 

From: electricboats@groups.io [mailto:electricboats@groups.io] On Behalf Of Ryan Sweet
Sent: Friday, August 20, 2021 7:34 AM
To: electricboats@groups.io
Subject: Re: [electricboats] Lifepo4 Batteries available and ready to ship from US

 

One more thing: I will warranty these stateside with spares, for five years. I fully expect them to last the lifetime of your boat (6000 cycles to 80% capacity), but nonetheless I am reserving spares for warranty issues just in case, and you would not have to wait for them to ship from China. 

On Aug 19, 2021, at 20:23, Ryan Sweet via groups.io <ryan=ryansweet.org@groups.io> wrote:



Ok, thank you Jeff… well then to simplify things, here is the site again:

 

https://www.pacificalgorithms.com/

 

Of course if you have questions drop me a line… 

 

If you live in the Puget Sound region, I may be able to deliver them or meet you for pickup.

 

Note that the inverters already sold out. Also in case it isn't clear, the powerwalls can be mounted laying flat, like any other lifepo4 they don't require a specific orientation. 

On Aug 19, 2021, at 19:51, reesekc <kcr@kcrproducts.com> wrote:



I have a Hughes 35.5 that I power with a Thunderstruck 10kw kit. I'm presently using 4 x 100 amp 13.2v lithium batteries to power the system at 48v, and used a DC to DC converter (48 >12) for "house power". I would be interested in having more battery storage.

 

On Thu, Aug 19, 2021 at 7:30 PM Ryan Sweet <ryan@ryansweet.org> wrote:

… I tried to look to find out what the policy here is on sharing commercial ventures…. I'm not finding the previous thread where that was discussed.  In any case, right now my setup is running more like a co-op since I'm passing goods on at basically the cost to me after customs, taxes, etc.

So - if you are interested in lifepo4 powerwalls (200ah each, each one has a C rate of 200a, hence will power an me 10kw motor), I have inventory finally and thus can ship to you from the US. Drop me a line and I can point you to my website for more info.

Regards,
-Ryan

Re: [electricboats] Lifepo4 Batteries available and ready to ship from US

Ryan,

What cells are you using?  Where does the 6000 cycles to 80% figure come from?  It looks like about 3750 at 80% in the cycle life chart in this document for the EVE 280AH cells.  I would expect the 200AH cells to be similar? 

http://www.dcmax.com.tw/LF280(3.2V280Ah).pdf


Dan Pfeiffer

 

On 2021-08-20 9:34 am, Ryan Sweet wrote:

One more thing: I will warranty these stateside with spares, for five years. I fully expect them to last the lifetime of your boat (6000 cycles to 80% capacity), but nonetheless I am reserving spares for warranty issues just in case, and you would not have to wait for them to ship from China. 

On Aug 19, 2021, at 20:23, Ryan Sweet via groups.io <ryan=ryansweet.org@groups.io> wrote:

Ok, thank you Jeff... well then to simplify things, here is the site again:

 

https://www.pacificalgorithms.com/

 

Of course if you have questions drop me a line... 

 

If you live in the Puget Sound region, I may be able to deliver them or meet you for pickup.

 

Note that the inverters already sold out. Also in case it isn't clear, the powerwalls can be mounted laying flat, like any other lifepo4 they don't require a specific orientation. 

On Aug 19, 2021, at 19:51, reesekc <kcr@kcrproducts.com> wrote:

I have a Hughes 35.5 that I power with a Thunderstruck 10kw kit. I'm presently using 4 x 100 amp 13.2v lithium batteries to power the system at 48v, and used a DC to DC converter (48 >12) for "house power". I would be interested in having more battery storage.

On Thu, Aug 19, 2021 at 7:30 PM Ryan Sweet <ryan@ryansweet.org> wrote:

... I tried to look to find out what the policy here is on sharing commercial ventures.... I'm not finding the previous thread where that was discussed.  In any case, right now my setup is running more like a co-op since I'm passing goods on at basically the cost to me after customs, taxes, etc.

So - if you are interested in lifepo4 powerwalls (200ah each, each one has a C rate of 200a, hence will power an me 10kw motor), I have inventory finally and thus can ship to you from the US. Drop me a line and I can point you to my website for more info.

Regards,
-Ryan

Re: [electricboats] Lifepo4 Batteries available and ready to ship from US

One more thing: I will warranty these stateside with spares, for five years. I fully expect them to last the lifetime of your boat (6000 cycles to 80% capacity), but nonetheless I am reserving spares for warranty issues just in case, and you would not have to wait for them to ship from China. 

On Aug 19, 2021, at 20:23, Ryan Sweet via groups.io <ryan=ryansweet.org@groups.io> wrote:



Ok, thank you Jeff… well then to simplify things, here is the site again:

https://www.pacificalgorithms.com/

Of course if you have questions drop me a line… 

If you live in the Puget Sound region, I may be able to deliver them or meet you for pickup.

Note that the inverters already sold out. Also in case it isn't clear, the powerwalls can be mounted laying flat, like any other lifepo4 they don't require a specific orientation. 

On Aug 19, 2021, at 19:51, reesekc <kcr@kcrproducts.com> wrote:



I have a Hughes 35.5 that I power with a Thunderstruck 10kw kit. I'm presently using 4 x 100 amp 13.2v lithium batteries to power the system at 48v, and used a DC to DC converter (48 >12) for "house power". I would be interested in having more battery storage.

On Thu, Aug 19, 2021 at 7:30 PM Ryan Sweet <ryan@ryansweet.org> wrote:

… I tried to look to find out what the policy here is on sharing commercial ventures…. I'm not finding the previous thread where that was discussed.  In any case, right now my setup is running more like a co-op since I'm passing goods on at basically the cost to me after customs, taxes, etc.

So - if you are interested in lifepo4 powerwalls (200ah each, each one has a C rate of 200a, hence will power an me 10kw motor), I have inventory finally and thus can ship to you from the US. Drop me a line and I can point you to my website for more info.

Regards,
-Ryan