Interesting read on Lithium


Mark Erdos
 

https://loosecannon.substack.com/p/youre-not-qualified-to-have-li-batteries?r=nzq2r&s=w&utm_campaign=post&utm_medium=web&fbclid=IwAR2IEih8volUg_ORyuhnPeYp4xdDqjQPT0YjYNDbfvH4L42hO66rkSRA9Qk

Really not wanting to start a heated debate on this, but thought I'd share for those interested in what a full-time very qualified accident investigator has to say.

 

 

With best regards,

 

Mark

 

Skipper

Sailing Vessel - Cream Puff - SM2K - #275

Currently cruising - Tahiti, French Polynesia

www.creampuff.us

 


David Wallace
 

 Note he's writing about Lithium Ion batteries. LiFePO4 batteries are quite different and much safer.

Dave Wallace
ex-s/v Air Ops
Maramu #104

On Apr 6, 2022, at 12:05 PM, Mark Erdos <mcerdos@...> wrote:

https://loosecannon.substack.com/p/youre-not-qualified-to-have-li-batteries?r=nzq2r&s=w&utm_campaign=post&utm_medium=web&fbclid=IwAR2IEih8volUg_ORyuhnPeYp4xdDqjQPT0YjYNDbfvH4L42hO66rkSRA9Qk

Really not wanting to start a heated debate on this, but thought I'd share for those interested in what a full-time very qualified accident investigator has to say.

 

 

With best regards,

 

Mark

 

Skipper
Sailing Vessel - Cream Puff - SM2K - #275
Currently cruising - Tahiti, French Polynesia

 



Bruno COTTE
 

No problem with LifeP04 batteries . Many insurance companies only cover fire with VICTRON or Mastervolt LifeP04 
Batteries . In particular if you have a fire with Chinese lion batteries you will not be covered 
Envoyé de mon iPhone

Le 6 avr. 2022 à 21:15, David Wallace <svairops@...> a écrit :

  Note he's writing about Lithium Ion batteries. LiFePO4 batteries are quite different and much safer.

Dave Wallace
ex-s/v Air Ops
Maramu #104

On Apr 6, 2022, at 12:05 PM, Mark Erdos <mcerdos@...> wrote:

https://loosecannon.substack.com/p/youre-not-qualified-to-have-li-batteries?r=nzq2r&s=w&utm_campaign=post&utm_medium=web&fbclid=IwAR2IEih8volUg_ORyuhnPeYp4xdDqjQPT0YjYNDbfvH4L42hO66rkSRA9Qk

Really not wanting to start a heated debate on this, but thought I'd share for those interested in what a full-time very qualified accident investigator has to say.

 

 

With best regards,

 

Mark

 

Skipper
Sailing Vessel - Cream Puff - SM2K - #275
Currently cruising - Tahiti, French Polynesia

 



EricOpdeweegh
 

Hi Mark,
Thank you for your concerns and article. Sure will not make a diy system but will have all certified by professionals and will take all safety measures into account.

Still the question remains : is there a way to safely install LiFePo4 cells in a block safely without hdp casings?

Fair winds
Eric 
Sv Abayomi 
Sm 158

Op 6 apr. 2022 om 21:05 heeft Mark Erdos <mcerdos@...> het volgende geschreven:



https://loosecannon.substack.com/p/youre-not-qualified-to-have-li-batteries?r=nzq2r&s=w&utm_campaign=post&utm_medium=web&fbclid=IwAR2IEih8volUg_ORyuhnPeYp4xdDqjQPT0YjYNDbfvH4L42hO66rkSRA9Qk

Really not wanting to start a heated debate on this, but thought I'd share for those interested in what a full-time very qualified accident investigator has to say.

 

 

With best regards,

 

Mark

 

Skipper

Sailing Vessel - Cream Puff - SM2K - #275

Currently cruising - Tahiti, French Polynesia

www.creampuff.us

 


Dean Gillies
 

Hi Eric,
You have received great advice from the knowledgeable people on this forum, and it sounds to me like you are progressing very sensibly.
  
I looked at the "Pureacell" link that you posted and would like to highlight one important detail that has not been mentioned. It is related to your HPDE question.

The "blue" cells that are advertised on that site are the standard Chinese prismatic cells. These are ubiquitous and are the cells that appear inside the majority of drop-in LiFePO4 batteries.  Pureacell advertise that they compress the cells between two plates, and show images of 4s and 8s blocks of cells with end-plates used to compress the blocks. The cells in each block appear to be placed firmly against one-another.

Those blue cells have aluminium enclosures which, by design, form part of the cell anode and are therefore electrically connected to the positive terminal. The blue insulating covers are rather thin. You (and your system designer) must be very aware of the potential for short circuit (no pun intended!) if the blue material is breached between adjacent cells.  Personally, I don't believe you need full HPDE cases on each cell, however I would strongly suggest that an additional insulating layer is required between adjacent cell enclosures so that you do not fully rely upon the blue material only.  I don't think that simply compressing a block of cells together between end plates properly mitigates this risk.

Good luck with the project.

Dean Gillies
SV Stella
A54-154

   



   


Dean Gillies
 

Eric,
I forgot to mention.. I like that you are thinking about the lead-acid backup option. 

Permanently connected Hybrid LiFePO4/Lead-Acid battery systems work really well, particularly if your emphasis is on "backup".  I have 540Ah of LiFePO4 behind my main BMS-controlled contactor and 115Ah of AGM which are permanently connected. I rarely take the LiFePO4 below about 25%, which means that the AGM are permanently on "float" due to the operating voltage of the LiFePO4. In the event that my LiFePO4 main contactor is disconnected (for any reason) then the AGM immediately and seamlessly takes up the load. The lights stay on and the navigation system continues to operate. 

There are other benefits too.  Floating LiFePO4 for long periods shortens their life. When my boat is in storage 6 months of the year, I set the LiFePO4 SOC to about 60% turn off the BMS and completely disconnect the cells.  The system then operates with the AGM's on float using solar and/or shore power, and I can monitor everything from the other side of the planet via 4G and the Victron VRM portal. 

Also, having 3 identical AGM's (one for start and two for house) means I get good redundancy in the event of a start battery failure.

Something else to ponder.

Dean
SV Stella
A54-154


EricOpdeweegh
 

Hi Dean,

 

Thank you for your constructive remark, very well observed. So happy the way everybody is making effort like this to comment. And contributing to come to the right decision.

Also learning some new English words and expressions on the way😊. (ubiquitous , no pun intended!)

I will certainly go for the isolation/separation plates between the individual cells.

 

 

One of the other things we have to look into is the continuous power and the maximum amperes due to the bowtruster usage.

 

The extra redundancy with gel or lead acid, you are talking about in the later email is something we are looking at too.

 

So much to learn.

 

To be continued and hope more pros and cons will be coming in from people with some professional experience

 

Fair winds and safe sailing

 

Eric Opdeweegh

Sv Abayomi SM 158

Phone  +31621240217

Email     sv.abayomi@...

 

Van: main@AmelYachtOwners.groups.io <main@AmelYachtOwners.groups.io> Namens Dean Gillies
Verzonden: donderdag 7 april 2022 03:44
Aan: main@AmelYachtOwners.groups.io
Onderwerp: Re: [AmelYachtOwners] Interesting read on Lithium

 

Hi Eric,
You have received great advice from the knowledgeable people on this forum, and it sounds to me like you are progressing very sensibly.
  
I looked at the "Pureacell" link that you posted and would like to highlight one important detail that has not been mentioned. It is related to your HPDE question.

The "blue" cells that are advertised on that site are the standard Chinese prismatic cells. These are ubiquitous and are the cells that appear inside the majority of drop-in LiFePO4 batteries.  Pureacell advertise that they compress the cells between two plates, and show images of 4s and 8s blocks of cells with end-plates used to compress the blocks. The cells in each block appear to be placed firmly against one-another.

Those blue cells have aluminium enclosures which, by design, form part of the cell anode and are therefore electrically connected to the positive terminal. The blue insulating covers are rather thin. You (and your system designer) must be very aware of the potential for short circuit (no pun intended!) if the blue material is breached between adjacent cells.  Personally, I don't believe you need full HPDE cases on each cell, however I would strongly suggest that an additional insulating layer is required between adjacent cell enclosures so that you do not fully rely upon the blue material only.  I don't think that simply compressing a block of cells together between end plates properly mitigates this risk.

Good luck with the project.

Dean Gillies
SV Stella
A54-154