Winston LiFePO4 questions

liamg

Hello,

I have few questions regarding the Winston LiFEPO4 batteries. 

(1) What's the difference betwen the "tall" and "wide" battery case variants? For example, they have two types of 100Ah cells with the following dimensions: 218x143x67 mm, weight: 3.3 kg (the "tall" one) and 218x179x62 mm, weight: 3.6 kg (the "wide" one).

For my aplication (off-grid solar system), the actual dimmensions doesn't matter, but is there any technological advantage of being tall (and slim) or being wide? Also, the "tall" one is lighter (3.3kg versus 3.6kg). Which one should be better? Does anyone know which one is representing a new (updated) product?

(2) They have a 12V pack (4 cells inside a box) which, according to the datasheet, are starting-up power battery for fuel cars. What does it means? I guess the cells were selected for higher discharge currents. Does it means the cells are overall better or there is a downside in regard to my application (off-grid energy storage)?

Any input is greatly appreciated!  

jonr

I would definitely want access to each individual cell for balancing.   Not sure you get that in a 12V pack.

liamg

They say the 12V box contains "finely balanced cells with identical perfomace" and "the battery must be managed as a single monolithic 12V block".

They also describe a procedure to remove the lid to access the individual cells (using a knife and a hammer!). The box looks handy to me (as the cells are kept together using some metallic rods and aluminium plates on both sides).

But how come they are so sure about the cells remaining balanced during the battery lifetime? 

PNjunction

liamg said:

They say the 12V box contains "finely balanced cells with identical perfomace" and "the battery must be managed as a single monolithic 12V block".

They also describe a procedure to remove the lid to access the individual cells (using a knife and a hammer!). The box looks handy to me (as the cells are kept together using some metallic rods and aluminium plates on both sides).

But how come they are so sure about the cells remaining balanced during the battery lifetime? 

What they have done is make sure that each cell is VERY close to each other not only in capacity, but also in internal resistance.

Random cells just picked off the line, and slapped together may differ quite a bit in both capacity and internal resistance.  Battery bms that use simplistic bleeder techniques hide this fact.  With reputable companies, one can usually specify that the cells they receive are finely matched, and even get a printout of performance - usually for an extra fee for those diy'ing it.

Thus, once top balanced, they stayed that way unless you abuse them.  A very similar thing occurs with higher-quality motorcycle LFP starting batteries.  Many don't include any bms.  Some do, some don't.

By being managed as a single 12v monolithic block implies that simple two-terminal charing like a Pb battery would be sufficient.  But of course, many users use the wrong chargers, wrong voltages etc.

If you want to treat it like a huge motorcycle starting battery (ie, the dreaded "drop in), one consumer type of charger you could apply would be a nice Tecmate-Optimate Lithium (LFP specific) charger.  If you abuse it, this will bring it back and perform some modicum of balancing to a simple 4S battery.  Not lab perfect, but good enough - at least in my own use.

mvas

liamg said:

They say the 12V box contains "finely balanced cells with identical performance" ... 

We call that "Marketing".
Do you have any proof what-so-ever that this actually occurs?

Is the warranty really only 1 Year?

liamg

The warranty is 1 year, indeed, and they have another nasty terms: you have to pay all the shipping taxes to exchange a DOA product!

Anyway, I guess I'll pass the LiFePO4 technology for now: seems like the NMC is the new "game changer" (though I bet it will be obsolete in a year or so).

That's it, there's no chance to buy a really mature product these days (except for the grandpa's Pb batteries).

liamg

[duplicated]

PNjunction

mvas - The relative ease one can cut one open to gain access to the individual cells, and use even consumer hobby-type instruments to measure individual charge, capacity, and internal resistance makes *quality* manufacturers do this.  Those that do might even be able to cross-reference their measurements against data sheets filed against the cells with serial #'s.

liamg - you won't get one "DOA" if you buy from a reputable seller / distributor.  However, most battery manufacturers have shortened their warrantees knowing that many consumers purposely buy the wrong battery for their application hoping to play the warranty-scam to get free batteries for life, or at least several "free" ones.  Either that, or they know that the average consumer just doesn't know the basics about LFP and is likely to kill it straight away.

Giveaways are the unwillingness to send back the old one first for evalution, having no proof of purchase, or inability to verify where the battery was purchased.  Then when the manufacturer / distributor refuses to play this game, the owner bashes it online, usually without any reputable back-story about the application it was put into.

It's a game played with Pb batteries - most automotive boards are filled with this type of scam from a few members.

In your case, the "NMC" is an entirely different lithium chemistry than lifepo4, and charging LFP with NMC voltages will kill it.  Hence the reluctance of many manufacturers to offer any warrantee at all to hobbies end users like ourselves who suspect that we are just going to wing it, kill it, and demand a refund or freebie.

mvas

PNjunction said:

mvas - The relative ease one can cut one open to gain access to the individual cells, and use even consumer hobby-type instruments to measure individual charge, capacity, and internal resistance makes *quality* manufacturers do this.  Those that do might even be able to cross-reference their measurements against data sheets filed against the cells with serial #'s.

So, do you actually buy two of everything, cut one open and then do destructive testing to prove that you actually purchased "Finely Balanced Cells"?  I don't.  And I don't know anybody who does.  Many off-shore companies habitually lie about a much simpler specification: the Amp-Hour Capacity. Testing the Amp-Hour capacity is easy to do.  And who has done that?  You, me and maybe handful of other people, but not any of your typical 4 Billion consumers. There is very little "truth in advertising".

What is WInston's definition of "Finely Balanced Cells".

  Are you telling me that they sort the cells at the factory, and then assemble some battery packs with all higher-end capacity cells and some battery packs with all lower-end capacity cells?  How is this higher-end capacity vs lower-end capacity actually labelled on each battery?  Because I would prefer a battery with all higher-end capacity cells.

Until I see a definition and proof that the cells are "Finely Balanced", it is just Marketing Hype.
Oh wait, maybe they are "New & Improved" ...

Lumisol

jonr said:

I would definitely want access to each individual cell for balancing.   Not sure you get that in a 12V pack.

Don't these normally have a built in balancing microprocessor circuit to handle that automatically?

Lumisol

mvas said:

PNjunction said:

mvas - The relative ease one can cut one open to gain access to the individual cells, and use even consumer hobby-type instruments to measure individual charge, capacity, and internal resistance makes *quality* manufacturers do this.  Those that do might even be able to cross-reference their measurements against data sheets filed against the cells with serial #'s.

So, do you actually buy two of everything, cut one open and then do destructive testing to prove that you actually purchased "Finely Balanced Cells"?  I don't.  And I don't know anybody who does.  Many off-shore companies habitually lie about a much simpler specification: the Amp-Hour Capacity. Testing the Amp-Hour capacity is easy to do.  And who has done that?  You, me and maybe handful of other people, but not any of your typical 4 Billion consumers. There is very little "truth in advertising".

What is WInston's definition of "Finely Balanced Cells".

  Are you telling me that they sort the cells at the factory, and then assemble some battery packs with all higher-end capacity cells and some battery packs with all lower-end capacity cells?  How is this higher-end capacity vs lower-end capacity actually labelled on each battery?  Because I would prefer a battery with all higher-end capacity cells.

Until I see a definition and proof that the cells are "Finely Balanced", it is just Marketing Hype.
Oh wait, maybe they are "New & Improved" ...

Using this logic, the only product you can trust is the one you make yourself. I have always said if you want something done right, do it yourself.

When you buy a new car, there is no proof that you are buying anything worth owning so do you just never drive a car again?

Estragon

There was a time, some us of a certain age may remember it, when buying a car was almost as much of a crap shoot as buying "finely balanced" banks of batteries from China.

BB.

Learned a fair amount of car repair from my father as a very young kid... Much of it on the two day trips from SF to Phonies Arizona and back that we would take every spring break to see my grandfather--In a 1962 International Harvester Scout. Had a full tool box and roll of bailing wire to fix whatever broke (virtually every trip). That engine (literally 1/2 of a V8 designed four banger). Would do its best to shake off everything bolted to the engine (shatter the generator bracket bolts, toss of the throttle linkage, go through a wheel bearing or two, etc.).

And there was the older Jaguar that had a piston and rod that wanted out of the engine block really bad to visit San Bernardino.

New (after the Japanese "invasion" of reliable and not very expensive) cars are just so much more reliable (on average) than any of the old iron.

-Bill

Lumisol

I remember my parents wrapping up a roast in a dozen layers of foil and putting it in a covered pot and strapping it to the engine on the way to Payson and having dinner cooked when we got there.

BTW, buying a car is still a crapshoot.

karrak

I am responsible for two off grid systems that use Winston batteries that are around four years old. Total number of cells is 64. To date I haven't had any problem with any of the Winston cells although I have a question mark over maybe one cell in my system.

I can see why lithium ion battery manufacturers would be hesitant  to give long warranties on the individual cells as they can be easily damaged if the final system that the cells are part of are is not designed, commissioned, and used properly. It should be a different matter if the battery is part of an integrated battery system with appropriate battery management and safety systems.

LiFePO4 (LFP) is not a fly by night technology. The first functional batteries were made in the 1990s. It has taken this long for the technology to be refined, tested and commercialised.

As far as I can see LFP batteries should have the edge over lithium technologies based around cobalt as they are safer and run at a lower cell voltage which implies that they should last longer. Having said this, the market for lithium cobalt based batteries is currently much larger than for LFP batteries so there has probably been much more work to extend the life of lithium cobalt based batteries.

Simon

liamg

PNjunction said:

you won't get one "DOA" if you buy from a reputable seller / distributor.  However, most battery manufacturers have shortened their warrantees knowing that many consumers purposely buy the wrong battery for their application hoping to play the warranty-scam to get free batteries for life, or at least several "free" ones.  Either that, or they know that the average consumer just doesn't know the basics about LFP and is likely to kill it straight away.

Giveaways are the unwillingness to send back the old one first for evalution, having no proof of purchase, or inability to verify where the battery was purchased.  Then when the manufacturer / distributor refuses to play this game, the owner bashes it online, usually without any reputable back-story about the application it was put into.

The vendor is quite a reputable one (ev-power.eu) but still a DOA could happen and sending a cell back and forth would cost me enough to disagree with this gamble.

PNjunction said:

In your case, the "NMC" is an entirely different lithium chemistry than lifepo4, and charging LFP with NMC voltages will kill it.  Hence the reluctance of many manufacturers to offer any warrantee at all to hobbies end users like ourselves who suspect that we are just going to wing it, kill it, and demand a refund or freebie.

I wasn't talking about NMC as a direct LiFePO4 replacement, as I'm going to review my entire charging system anyway if/when I'm going to switch to a different battery chemistry. Regarding the "users killing their batteries" - that should be a valid point but I guess the vendor/manufacturer could distinguish between an abused battery and a DOA one. Couldn't they?

liamg

karrak said:

LiFePO4 (LFP) is not a fly by night technology. The first functional batteries were made in the 1990s. It has taken this long for the technology to be refined, tested and commercialised.

Your statement is correct - the LiFePO4 has a known past but I was talking about its future. I've read a document about the chinesse government putting a pressure on manufacturers to reach a power density of 200Wh/kg  for their (EV) batteries and it seems that the LiFePO4 could not keep up with those regulations.

That's why I thought of taking a break with my next purchase until this "chemistry war" it's over (will it ever?).

mvas

Lumisol said:

jonr said:

I would definitely want access to each individual cell for balancing.   Not sure you get that in a 12V pack.

Don't these normally have a built in balancing microprocessor circuit to handle that automatically?

I searched the Winston website and I cannot find where it states "BMS is Included or not included"
Are all of the Winston cells / batteries sold as unprotected?
It appears that there are multiple terminal connections for external BMS, on the batteries that have series connected cells.
I am waiting for a reply email from Winston.

liamg

None of the Winston 12V battery blocks have any BMS included. Quote from the vendor product page:

NOTE:
The monolithic 12V batteries do not have any PCM (any electronics) inside. They consist of finely balanced cells with identical perfomace. The battery must be managed as a single monolithic 12V block.

Anyway, I guess none of the LiFePO4 cells came with the BMS included. Usually, a BMS is monitoring a large number of cells.

Lumisol

Estragon said:

There was a time, some us of a certain age may remember it, when buying a car was almost as much of a crap shoot as buying "finely balanced" banks of batteries from China.

It's kind of like buying "fine electronics made by Apple" that are made in China.

mvas

liamg said:

None of the Winston 12V battery blocks have any BMS included. Quote from the vendor product page:

NOTE:
The monolithic 12V batteries do not have any PCM (any electronics) inside. They consist of finely balanced cells with identical perfomace. The battery must be managed as a single monolithic 12V block.

Anyway, I guess none of the LiFePO4 cells came with the BMS included. Usually, a BMS is monitoring a large number of cells.

Thanks, for the link to the "GWL Power" website, which has the answer.
Very odd that Winston's website http://en.winston-battery.com/ has nothing on the subject.
Just learned that it may be called: BMS, PCM or, PCB.

Lumisol

BMS=Battery Management System (sometimes also 'monitoring')
PCM=Pulse Code Modulation
PCB=Printed Circuit Board

mvas

As they apply to Lithium Ion Batteries ...
BMS = Battery Management System
PCM = Protection Circuit Module
PCB = Protection Circuit Board

Lumisol

I think the former are more widely used than the latter.

BB.

Every occupation has its abbreviation--And, many times, they use the same TLA's from other disciplines. Perfectly valid, but can be confusing (TLA--Three Letter Acronym  Top Level Assembly, are a couple variants I have used at work). TLA:

http://acronyms.thefreedictionary.com/TLA

TLA

	Three Letter Acronym
TLA	Three Letter Abbreviation
TLA	Texas Library Association
TLA	The Last Airbender (movie and TV series)
TLA	Text-Link-Ads (Internet advertising)
TLA	Top-Level Aggregation
TLA	Temporal Logic of Actions (logic system)
TLA	Tennessee Library Association
TLA	The Lost Age (game)
TLA	Theater of the Living Arts (Philadelphia, PA)
TLA	Temporary Lodging Allowance
TLA	Teaching, Learning and Assessment
TLA	Teacher Learning Academy (UK)
TLA	The Language Academy (Fort Lauderdale, FL)
TLA	Trial Lawyers Association
TLA	True Love Always
TLA	Transportation Lawyers Association
TLA	Total Laboratory Automation
TLA	Temporary Living Allowance
TLA	Thin Layer Activation
TLA	The Lawrence Arms (band)
TLA	Territorial Local Authorities (New Zealand)
TLA	Transformative Language Arts (Goddard College)
TLA	The Last Alliance
TLA	Top Level Architecture (information security defense-in-depth)
TLA	Timber License Agreement (Philippines)
TLA	Truth in Lending Act
TLA	Trinidad Lake Asphalt
TLA	Teller, Alaska (Airport Code)
TLA	Term Loan A
TLA	Three Letter Agency
TLA	Throttle Lever Angle
TLA	Top Level Assembly
TLA	Tournament Life Announcement (chess)
TLA	Two Letter Acronym (less common)
TLA	Top Level Aggregate
TLA	Training Level Assignment
TLA	Transluminal Angioplasty (navigating transluminally through blood vessels to perform angioplasty.
TLA	Terminal Lecteur Applicatif (French: Terminal Drive Application)
TLA	Temporary Lodging Assistance
TLA	Two-Location Algorithm
TLA	The Last Ambassadors (band)
TLA	Talk, Listen, Act (United Parcel Service training)
TLA	Telephone Line Adapter
TLA	Transmit Level Adjustment
TLA	Termination Liability Agreement
TLA	Toulouse Lalande-Aucamville (French rugby club)
TLA	True Life Anatomy Pty Ltd (software)
TLA	Triathlon du Lac d'Aiguebelette (French triathlon)
TLA	Time Line Analysis
TLA	Telemetry Link Adapter
TLA	Tenant Lease Agreement
TLA	Travel & Living Allowance
TLA	Total Living Allowance
TLA	Term Life Assurance
TLA	Teaching and Learning Assistant (education)
TLA	Terminal Low Altitude
TLA	Terminate and Leave Activated
TLA	Tie Line Class A (24 hours/day service)
TLA	Triple Letter Acronym (less common than Three Letter Acronym)
TLA	Techniques Loisirs Automobiles (French automobile service company)
TLA	Tissue-Like Assemblies
TLA	Theater Lead Agent (US DoD)
TLA	Transmitter Launch Amplitude
TLA	Talk-Listen-Action
TLA	Tamilnadu Library Association (India)
TLA	Top Level Alarm
TLA	Top-Level Administrator (computing)
TLA	The Latin Americanist (journal; Southeastern Council of Latin American Studies)
TLA	The Lost Art
TLA	Teaching and Learning Activities
TLA	Technology Licensing Agreement (contract)
TLA	Telstra Learning Academy (Australia)

Why it is nice to spell out the Three Letter Acronym first and put in brackets (TLA) for the rest of the conversation.

-Bill

Lumisol

Exactly, using an often otherwise used initialism, is just confusing and sometimes a lazy way of typing.

The PCB, PCM, TLA and BMS are all initialisms, not acronyms. An acronym is an initialism that is pronounceable, like NASA or NAFTA, an initialism is not pronounceable and is pronounced as the letters that make it up, like CIA and FBI.