# lithium sulphur



## MN Driver (Sep 29, 2009)

I'm trying to figure out what is so exciting about them. The smallest cell is 600Ah which means you'll end up using a very low voltage system, the graphs make it look like its about 1.7 volts nominal so you'll end up with a low voltage pack unless you have a desire for lots of capacity and weight. They seem to have a similar weight to capacity as LiFePO4 but without knowing the nominal voltage, it is hard to say but it looks close.

FWIW, Jack Rickard wanted to try these out on his Cadillac Escalade but he instead got 400Ah LiFePO4 because the Lithium Sulpher cells weren't ready for customers yet, that was after Winston-battery started their own thing and before the news broke about the ugly split of the company into Winston and Sinopoly.


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## jeremyjs (Sep 22, 2010)

MN Driver said:


> I'm trying to figure out what is so exciting about them. The smallest cell is 600Ah which means you'll end up using a very low voltage system, the graphs make it look like its about 1.7 volts nominal so you'll end up with a low voltage pack unless you have a desire for lots of capacity and weight. They seem to have a similar weight to capacity as LiFePO4 but without knowing the nominal voltage, it is hard to say but it looks close.
> 
> FWIW, Jack Rickard wanted to try these out on his Cadillac Escalade but he instead got 400Ah LiFePO4 because the Lithium Sulpher cells weren't ready for customers yet, that was after Winston-battery started their own thing and before the news broke about the ugly split of the company into Winston and Sinopoly.


Agreed. In those sizes they're not too useful for a car unless you're going for a low voltage system. Hopefully if/when they do start producing them they'll have something in the 100-200 ah size range. Even at 1.7v nominal these things would have almost 2x the wh/kg of the lifepo4 though; which is why I find them interesting. That's why I was wondering if anyone had heard anything. So long as they're relatively safe, won't explode/catch fire if over charged/discharged, they could be awesome if the specs they're giving are accurate.


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## bjfreeman (Dec 7, 2011)

Electrical Specifications:
Nominal Voltage: 2.15V
Maximum Charge Voltage: 2.5V
Minimum Voltage on Discharge: 1.7V
Nominal Capacity @ 25C: 2.5 Ah @ C/5
Maximum continuous discharge rate: 2C
Maximum charge rate: C/5
Specific Energy: 350 Wh/kg
Energy Density: 320 Wh/l


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## jeremyjs (Sep 22, 2010)

bjfreeman said:


> Electrical Specifications:
> Nominal Voltage: 2.15V
> Maximum Charge Voltage: 2.5V
> Minimum Voltage on Discharge: 1.7V
> ...


What battery is that?


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## bjfreeman (Dec 7, 2011)

jeremyjs said:


> What battery is that?


got it from this site
 

not a big one, but the other specs should be the same.


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## MN Driver (Sep 29, 2009)

bjfreeman said:


> Electrical Specifications:
> Nominal Voltage: 2.15V
> Maximum Charge Voltage: 2.5V
> Minimum Voltage on Discharge: 1.7V
> ...


That's a bit weird to me. Either the graphs are strange or the Lithium Sulfur cells show 1C right at the specifications you posted above as being the minimum voltage on discharge. Seems the nominal voltage isn't the same on the Winston cells or the graphs are wrong, I have no way of knowing and not even a small amount of information to make an educated guess. The 2C draw is right below 1.6v and 5C is 1.3v. I can't imagine pulling 5C from a 600Ah cell though. ..but considering a cell so large and heavy at 11.66 pounds per cell, I'd imagine you aren't going to have a high voltage system and would probably be pulling some heavy amperage. Not sure what motor would be suitable for the job of a very low voltage system with high amps. It feels like lead-acid thinking to me IMHO, granted I'm sure they will last tons longer versus lead-acid but the large Ah and low voltage aspect is hard to get my head around.

http://en.winston-battery.com/index.php/products/power-battery/item/wb-lsp600aha?category_id=183


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## GuySmily (May 11, 2012)

Whoa, that is a LOT lighter: 9 lbs/kWh for Li-S vs ~24lbs/kWh for LiFePO4, assuming 2.15 volts (from the sionpower link) for the Winston Li-S cell.

https://docs.google.com/spreadsheet/ccc?key=0AvMX8BQDtW6kdHBid1ZnQ2tXa3RZX1IyZzBQN0pSMUE
edit: fixed link


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## Elithion (Oct 6, 2009)

From a power handling stand point (1 C or more current), the Winston Lithium sulphur cells have the highest specific resistance of any of the 20 Li-ion technologies that I have analyzed. That is, a battery of given voltage and capacity will have the highest internal resistance (and the lowest efficiency) if built with these cells compared to using just about any other Li-ion cell. Specifically: 45 % more resistance than standard Thundersky LiFeYPO4, 2.5 times the A123 20 Ah pouch, 4.7 times the Valence cells, 14 times the Kokam high power LiPo cells.

(I am not talking about energy density in slow discharge application; I am just talking about power handling and efficiency in power applications.)

Secondarily, a battery using these cells will require a BMS with twice the tap points as a battery using LiPo cells (unless one were to monitor 2 cells in series as a single cell).

I believe these cells are worthy of consideration for low voltage (<= 12 V), long discharge (>= 10 hour) applications.


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## rmay635703 (Oct 23, 2008)

To me its all about price, if sulphur cells are half the cost per Wthr, I wouldn't care, a 48-96v pack is all I need and lots of ahr would be excellent, 100-200miles range would be easy.


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## MN Driver (Sep 29, 2009)

Thanks for the analysis Davide. I'd imagine that these are what Winston was trying to put into his '1000 mile bus'. That would mean a huge capacity of these less capable cells that won't get pulled into a deep C discharge. I'd imagine if there was a fairly aerodynamic vehicle that could handle a substantial amount of weight at the same time that something like this might make sense for someone looking to have a long-range project without lots of performance. It would be an upgrade for a heavy lead-acid pack where the original owner put over 1000 pounds of lead into the car and was able to fit 1000 pounds of these in their place. You'd really need some space though.


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## rmay635703 (Oct 23, 2008)

Elithion said:


> From a power handling stand point (1 C or more current), the Winston Lithium sulphur cells have the highest specific resistance of any of the 20 Li-ion technologies that I have analyzed.
> 
> I believe these cells are worthy of consideration for low voltage (<= 12 V), long discharge (>= 10 hour) applications.


The real question is how much of a peukert affect would these have?

I doubt they are anywhere near FLA levels and would be ideal for the many folks who already have a FLA pack and want to upgrade for range.

In my case steady state driving is from 50-150amps depending on speed, my controller peaks at 275 amps, my goal ahr would be 300-600 ahr, so I don't think the resistance would be real bad.

Also if you have enough capacity you could skimp on the BMS and have a simple pack divided style sensor and not charge beyond a specific point or discharge past a specific point. 

The main question is will these become the loss leader or be considered cutting edge and expensive?


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## jumpjack (Sep 9, 2012)

I thought LiS battery were yet to come.... instead they're here already? They have 2 to 4 times standard LiFePO4 capacity! (80Wh/kg for Winston) What about the costs?
Why so big capacity only? Can't smaller batteries be built in LiS technology?
Within the 60 kg my old e-scooter has for LeadAcid batteries (38 fake-Ah, 20 real-Ah) I could put up to 17500 Wh!!!  Or "just" 12500 considering 250 Wh for Winston cells.
At a consumption of 40Wh/kg typical for my 48V scooter, that would mean 300 to 430 km!!


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## jeremyjs (Sep 22, 2010)

jumpjack said:


> I thought LiS battery were yet to come.... instead they're here already? They have 2 to 4 times standard LiFePO4 capacity! (80Wh/kg for Winston) What about the costs?
> Why so big capacity only? Can't smaller batteries be built in LiS technology?
> Within the 60 kg my old e-scooter has for LeadAcid batteries (38 fake-Ah, 20 real-Ah) I could put up to 17500 Wh!!!  Or "just" 12500 considering 250 Wh for Winston cells.
> At a consumption of 40Wh/kg typical for my 48V scooter, that would mean 300 to 430 km!!


It looks like they're still not available. Apparently a lithium sulfur chemistry battery, is a tough nut to crack.


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## jumpjack (Sep 9, 2012)

jeremyjs said:


> It looks like they're still not available. Apparently a lithium sulfur chemistry battery, is a tough nut to crack.


I found them!
enershop.generplus.it/product_info.php?cPath=33_35&products_id=32

580 Eur/kWh w.r.t. 420 for LYP.

But why such gigantic capacity only?!?


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## racunniff (Jan 14, 2009)

jumpjack said:


> I found them!
> enershop.generplus.it/product_info.php?cPath=33_35&products_id=32
> 
> 580 Eur/kWh w.r.t. 420 for LYP.
> ...


I don't know why the capacity (probably related to intended application), but its energy density per cubic cm seems lower than LiFePO4. The linked cell is 300Ah at (guessing) 2.1v nominal giving 630 Wh. Its volume is about 6400 cc, so its density is 0.098 Wh/cc.

In comparison, the CA180FI has a nominal capacity of 180*3.2 or about 580 Wh and its volume is about 3500cc, giving its density as roughly 0.170 Wh/cc - significantly higher.

Of course, the density per Kg is a different story - the Winston LSP looks to have about 630/5.3 = 119 Wh/Kg, whereas the CA180FI has 103 Wh/Kg. But, for the purposes of squeezing a lot of Wh into not a lot of cc (i.e. electric automobiles  LiFePO4 looks like it still has an advantage.


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## jumpjack (Sep 9, 2012)

racunniff said:


> I don't know why the capacity (probably related to intended application), but its energy density per cubic cm seems lower than LiFePO4. The linked cell is 300Ah at (guessing)


why in the world do you suppose 300Ah for a cell named LSP600AHA with "capacità 600 Ah" text in its data???


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## jeremyjs (Sep 22, 2010)

Yep. Thats a 600 ah cell. So double your numbers.


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## racunniff (Jan 14, 2009)

jeremyjs said:


> Yep. Thats a 600 ah cell. So double your numbers.


Oops, yes. Not sure what happened, brain slip in my spreadsheet entry which carried through to everything else.

This looks substantially better then - call it 2 Wh/cc vs. 1.7 Wh/cc. Hmm. The only other drawback is the voltage is significantly lower, but would maybe not be a major problem for DC conversions (I really like my AC conversions at 240V or higher


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## jumpjack (Sep 9, 2012)

What happened to Winston sulfur cells? 
Withdrawn?

Other manufacturers around?


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