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caipirinha · 28-02-2017, 12:17

Hi Alan
A few posts in this thread were discussing large cells on boats, with the recommendation to stay at 200 Ah max for any application (boat, RV, etc) where the cells would be subject to shocks, vibration, heel etc.
If I had access to cheap cells in the size you mention I would use them for my home.

PacificGreen · 28-02-2017, 14:00

Quote:

Originally Posted by caipirinha

Hi Alan
A few posts in this thread were discussing large cells on boats, with the recommendation to stay at 200 Ah max for any application (boat, RV, etc) where the cells would be subject to shocks, vibration, heel etc.
If I had access to cheap cells in the size you mention I would use them for my home.

Much of this is repeated without substantiation or proof other than what one person says or believes. Much of it is based on the experience of a grounding of a racing boat which is highly questionable. Much of the fud may also be related to some manufacturers pushing only certain cells. Large format prismatic cells are used quite successfully in many installations and most manufacturers and distributors have no opinion ether way.

If in fact one person called Ralph has some trouble with his cells is neither here nor there but can certainly be worth considering in your decision. I'm not familiar with the Ralph case myself. You might find earlier in this post #112 one person did a very nice job with large cells. You won't replicate that with small cells ever. Also find http://www.deny.org as a good source of information regarding large cells. Also they do install 10000 ah cells on submarines so you have to really wonder where this 200ah cell limit comes from.

I would buy the cells after verifying there voltage levels and date of manufacture.

offpist · 28-02-2017, 15:15

Quote:

Originally Posted by Hkalan

Hello,

I have an opportunity to pick up 16 Winston Cells 3.2v 1,000Ah from a local battery distributor that is closing its doors in a few months. Price is too good to pass !!

I don't read allot about the higher Ah cells, and curious of what the "cons" would be.

My 400Ah Calb cells are the bee's knees. But I cannot find any major discussions on higher Ah cells.

Would appreciate any feedback !

Alan

We have 4 of these winston 1000ah onboard, and i know 3 other boats with same cells. No problem but make sure you build the battery box so the cells can not move.

I would say go for it!

exMaggieDrum · 01-03-2017, 08:15

Quote:

Originally Posted by caipirinha

Hi Alan
A few posts in this thread were discussing large cells on boats, with the recommendation to stay at 200 Ah max for any application (boat, RV, etc) where the cells would be subject to shocks, vibration, heel etc.
If I had access to cheap cells in the size you mention I would use them for my home.

All the quotes I got for LFP cells were priced per Ah regardless of size. Someone above mentioned a "sale" for 1000Ah cells. That would be an anomaly for what I experienced but understandable. The price was not given but may certainly be "too good to pass up".

Regarding some examples given as to large cells being put on boats that have experienced no problems, submarines certainly are not subjected to the shock loads that an offshore cruiser has to endure, sometimes for several days in a row. I know of several local inshore boats who have LFP cells as well, and they don't venture out where it gets too rough either, so again not a apples to apples example.

Any kind of shore installation, including vehicles or phone switching installations would certainly not be valid comparisons.

I personally don't have any reason to know if larger cells may not be fine in a shock-load environment so I am not stating that they do or don't. However I would give some credence when a manufacturer says they are not recommended though. From an engineering view though I can envision how the interior cells of larger units are just the same construction as smaller cells only with larger internal connections. But the bigger internal cells would definitely have more mass and inertia so I can envision the possibility that that would over-stress the internal construction, or not. Just saying it might be a factor.

I don't see any economic reason why manufacturers would do give warnings about the size of cells suitable for different applications other than they don't want customers to have problems with their cells.

As to all of you who sound so authoritative on the subject, it would be helpful if you could explain to the rest of us why you are so sure of what you are saying. E.g. whether you have been an engineer or involved in the manufacture of LFP cells. Since no one has said so so far, I suspect not.

SV THIRD DAY · 01-03-2017, 08:26

I don't buy the story about larger cells having problems on boats and the LiFePO4 manufacturers I have spoken to laughed when I asked if the larger AH cells would be a problem on a boat. They said "have you ever seen a car driving down a bumpy road for hours on end". As I've seen many times, something gets said and then it becomes "chat room law" gaining more credence with each re-telling.

exMaggieDrum · 01-03-2017, 09:13

Quote:

Originally Posted by SV THIRD DAY

I don't buy the story about larger cells having problems on boats and the LiFePO4 manufacturers I have spoken to laughed when I asked if the larger AH cells would be a problem on a boat. They said "have you ever seen a car driving down a bumpy road for hours on end". As I've seen many times, something gets said and then it becomes "chat room law" gaining more credence with each re-telling.

Like I said Rich, I don't know personally. The "best" comment I have heard is someone saying a manufacturer told them not to use bigger cells. I cannot vouch for that any more than you can. Everything else is indeed just chat. Show us why you are so sure so this discussion can become more fact based.

I don't buy the car argument for one second. The car manufacturers certainly buy batteries to spec and not off the shelf. I have watched the manufacture of a couple of the car types and the cells don't resemble the ones put on boats in any form or fashion. May some DIY's use them but not the big guys who are mass producing them.

All you have to do to settle this is to quote an authoritative source. It is very hard to prove a negative but easy to say.

SV THIRD DAY · 01-03-2017, 09:43

I've spoken to enough battery manufactures to be personally comfortable that the larger AH batteries are not a problem on a boat. My own research was good enough for me...stories from one guy who I don't know from a single battery seller that could have been pushing his own smaller cell doesn't get me all that excited. I don't sell or push batteries..so I don't have any dog in the fight other than just watching how the game is played.

The Game illustrates just how dangerous the internet chat rooms can be. As you said...one guy said and now every time someone asks about larger cells BOOM...well everyone knows the larger cells are dangerous to put on a boat they will fail bla bla bla...and intricate arguments and explanations are made around the Meme. That's the way this stuff works...I see it all the time not just on this topic but it's a general internet grapevine game.

When battery manufactures without something to be gained tell me something...I tend to believe them over an anonymous internet chat room post....but what do I know...I've been running a LiFePO4 battery bank without a BMS now for 3yrs...flirting with certain death...ha ah ah

evm1024 · 01-03-2017, 10:05

As I recall those large cells are installed in trucks and busses. And do take a lot of abuse in terms of crappy roads.

Plus for me if I had a 1000 AH bank it would allow for a full 200 AH daily energy budget while cycling your bank from 60% SOC to 40% SOC.

I only have 700 AH on my boat but would take 1000 AH or even 2000 AH if offered.

The only drawback I see is size and the loss of a single 1000AH cell dropping your bank voltage to 9.6 volts (with the bad cell bypassed).... Hence a 2000 AH bank. Lose a cell and you still have 1000 AH and the cycling is nothing percent wise.

Just as changing to LiFePO4 requires a mindset change, the change to an excessive large bank also requires a mindset change.

john61ct · 01-03-2017, 10:18

Looking for tips, links, posts etc on plate & strapping for cell containment, DIY or at least low cost.

Have 60A CALB cells, looking to create blocks from 12V x4 cells, maybe bigger (advice?).

I plan to stay right away from the top and bottom knees, low-amp discharging, <14V charging, but maybe temperature issues both high and low.

Should I really worry about swelling?

If not, I may look to right-sized ready-made metal boxes with wooden (maybe foam?) spacer inserts to make a tight fit.

Any advice welcome.

SV THIRD DAY · 01-03-2017, 10:28

I would take a 1000AH bank myself.
The 400AH bank I have now (4-400A cells) is great, but it would be nice to be able to last longer during foggy/rainy days without the need to charge with the generator. It's only money right...

alctel · 01-03-2017, 10:30

Well, I just sent off 3000 CAD and will get a 8x200AH Sinopoly cells back in a few months.

Excited! Now to figure out what BMS to use. Thanks to all for all the useful stuff in here.

I thought long and hard as I was tempted just to go with 200AH as my daily usage is really pretty low and my 200 watts of solar more than keeps up when I'm at anchor.

PacificGreen · 01-03-2017, 15:18

Here is a great article to read:

Braided Copper Ground Straps. - EVTV Motor Verks

Jack also has a great video to watch regarding what constitutes a cell failure and why along with how it happens:

https://www.youtube.com/watch?v=bUWwZme4DIc

Otherwise the bolt spec alone is a great review and if you have actual samples to hold in your hand to compare with the differences are very apparent:

Recommended Bolt Recommended Lug Torque (ft-lbs, Nm) 40AH M6x16 - M6x20 1/4" 7, 9 70AH M6x16 - M6x20 1/4" 7, 9 100AH M8x16 - M8x20 5/16" 15, 20 130AH M8x16 - M8x20 5/16" 15, 20 180AH M8x16 - M8x20 5/16" 15, 20 400AH M14x16 - M14x20 9/16" 45, 60

There is also the UN38.3 Ratings and all batteries must pass this so if you have or are going to buy lithium batteries be that big or small consider they have undergone this test for you specified product. These are some examples and worthy of reading:

lithium & solar power LiFePO4
http://www.faktor.de/out/media/WB-LY...UN38.3-Eng.pdf
http://www.faktor.de/out/media/WB-LY...UN38.3-Eng.pdf
http://www.faktor.de/out/media/WB-LY...UN38.3-Eng.pdf

Speaking in terms of electric vehicles higher voltages are a requirement as that industry has quickly moved past 48,72,96,144 volt electric motors and the supporting manufacturers and infrastructure is slowly catching up. So for example if you wanted a solar charge controller for a boat running +300v you would have to special order that.

So for higher voltages yes electric vehicle manufacturers are opting for smaller cells to obtain those higher voltages and have a footprint they can still make something look like a car and not a bus that still has all the aesthetically pleasing appearances and characteristics of a car.

Opposite to that is a boat - generally much larger in comparison so the miniaturization of cells does not have to occur except in cases where the boat owners are constrained by space or weight requirements. By simply opting for smaller cells when larger format prismatic cells are available to achieve the same level of energy storage boat owners knowingly commit to more complex 12v packs.

Moving beyond the typical 12v mindset is a necessity for the industry as a whole and settling somewhere around 48v is easily achievable as commodity chargers, controllers are still readily available. This in turn results in larger format cells achieving the same amount of energy storage with less connections.

In terms of electric vehicles we only need to research a market much larger than the North American market Chinese-Made Electric Cars | ChinaAutoWeb to see that all variations of electric vehicles using many combinations of battery sizes and types have been adopted. Still industry would love to have a standardized portfolio of overly complex and engineered systems so as to inhibit the actual maintenance of these packs by mere owners.

So far as one manufacturer not recommending larger format cells that was pretty clear to the reason especially for that reseller of cells in #104 by Alctel. Pretty obvious they still like to make sales and will set the hook however they need to. Most people though will believe what they want and buy what they want even when the obvious is right in front of them.

What I find ludicrous is that the same type of salesman talk gets repeated as facts online and spread around as if it were in fact the truth without substantiation thereof as in here: Building a marine lithium battery | Nordkyn Design

This sets a dangerous precedent for existing and upcoming installations with large format cells based on entirely nothing but ******** from a salesperson. I will gladly read more thesis papers, research papers on anything to do with lifepo4 especially if some can be found addressing this topic. Sources?

We can theoretically expand on that in terms of production runs of smaller cells taking away capacity of the larger cells. CALB and Winston Battery get much order from EV producer but from a consumer purchaser perspective do we have much choice if a local supplier does not have a readily available product to sell? Yes you source from oversea or directly from China yourself.

exMaggieDrum · 02-03-2017, 06:29

Rich, if you have spoken directly with manufacturers, and not with the sales guys then I would take a lot of comfort from what they say. That there is one report of speaking direct with a manufacturer not to do so would be important too.

As far as car on crappy roads, they is absolutely no comparison to a boat in a heavy seaway to a truck on crappy roads. I used to do a LOT of 4wheeling and I never experienced that level of punishment, ever. Boats don't have shocks and springs. A crash would certainly be a heavy shock. I would think in that case the batteries might be damaged.

I am NOT arguing that large cells are not sturdy enough for a sea going small boat, just that the examples that "prove" they are are not credible when it comes to comparing them to cars/trucks.

I don't have any reason to say any of this. I would definitely liked to have larger cells but don't have a spot to put them in, so I went with smaller cells. In fact, I went with smaller cells at a specific height because of headroom available.

You are right that chat rooms and forums are a really good place to put forth alternative facts, just like presidents do.

I'm not going to chip in any more on this subject. This is a horse completely beaten to death, but without any definitive proof. So be it. None of us is going to build a lab with a shock table to duplicate life on a sailboat in 15-20' waves (or higher) and then test enough cells to see what they can handle, and that with cells from different manufacturers.

Typhoon · 02-03-2017, 06:51

Quote:

Originally Posted by alctel

Well, I just sent off 3000 CAD and will get a 8x200AH Sinopoly cells back in a few months.

Excited! Now to figure out what BMS to use. Thanks to all for all the useful stuff in here.

I thought long and hard as I was tempted just to go with 200AH as my daily usage is really pretty low and my 200 watts of solar more than keeps up when I'm at anchor.

Did you get your cells from Randy at Canev ?

Regards John.