[jeremyjs]

I was just wondering if anyone's heard anything about these batteries. I know sometime last year the word was about a year until you could buy them. The current listed formats are a bit big for a car conversion, but the energy density is very encouraging. Below is the link to the potential LSP batteries on the Winston site.

http://en.winston-battery.com/index....ry/lsp-battery

[MN Driver]

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.

[jeremyjs]

Originally Posted by MN Driver

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.

[bjfreeman]

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

[jeremyjs]

Originally Posted by bjfreeman

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

What battery is that?

[bjfreeman]

Originally Posted by jeremyjs

What battery is that?

got it from this site


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

[MN Driver]

Originally Posted by bjfreeman

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

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....ategory_id=183

[GuySmily]

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/...1IyZzBQN0pSMUE
edit: fixed link

[Elithion]

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.

[rmay635703]

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.