Latest Report from LiFeBATT

[Battboy]

Tom in Sandia Laboratory, New Mexico told us today that our 40138 cell has already passed 2000 cycles at 4C rating @ 1.5 minutes. He expects our battery to last 10,000 cycles or more, and it still works great! He can't write the report yet, because the life cycle test is not finished, but he will tell people who have interest to know right now. Report is due out when the cells go dead. This might take some time! We don't mind at all. If anyone has a need to verify this news, write me and I can give you Tom's phone number at Sandia Labs.

Our cells have already passed all the destructive testing and other tests that Sandia typically applies to battery cell testing. Tom said that these cells are by far the best performing they have tested yet in their laboratory. A manufacturer in China by the name of AA Power sent him a pack to test and it went kaput before 300 cycles in testing.

This also means our LiFeBATT cells will also work extremely well for "storage applications", so those of you who have Telco contacts, start spreading the word! Solar will also work well with our cells. We are planning a major revision of the LiFeBATT website, in about two weeks. Please visit us then to see the latest developments: http://www.lifebatt.com Our new 1210C Hard Packs will be available in early February and we will have complete specs on these packs on the new website. We continue to support Bob & Gary in their e-bike packs and have granted them an exclusive LiFeBATT Distributorship in the U.S. for these products. You will shortly find their offering on their website: http://www.tppacks.com

Also, LiFeBATT, Taiwan is preparing a " New Products Announcement Ceremony" this month in the Taipei world trade center for all our potential customers, some big potential investors and the Industral Development Bureau (IDB) of theTW Government. It will be the first debut of our "GlobeTRAC" gsm system worldwide. This technology event will be opened to the public and shall get the attention of the world media. We will also install a LiFeBATT system on a vehicle and let customers have the "seeing is believing" experience.

Don Harmon

 

[Jozzer]

Excellent news Don, Congratulations! Your bringing a wonderfull product to a desperate market

 

[Battboy]

Trying our best!

 

[Arbiker501]

Don,

WOW, This is where lifebatt shines.. I am looking forward to more info as well.

 

[recumbent]

Congradulations for passing the 2000 cycle test and more! I hope the elements don't degrade too much with time, but I guess they try to simulate that also with heat and such. Great news, hope to see Lifebatt reach the top of their game. Should we start buying stocks in the company now that they are low enough ?

 

[Battboy]

I plan on buying some shares myself !

 

[Battboy]

Congradulations for passing the 2000 cycle test and more! I hope the elements don't degrade too much with time, but I guess they try to simulate that also with heat and such. Great news, hope to see Lifebatt reach the top of their game. Should we start buying stocks in the company now that they are low enough ?

I just received this email today from Sandia Labs as an Update:

LifeBatt Testing Update:
After receiving your LiFeBatt cells in November of 2007, I began a limited test procedure to evaluate performance. The testing included the following:

1) Capacity measurements at 1C (10A) rate.
Results: Capacity was within specification

2) Ohmic resistance measurement
Results: Resistance was within specification

3) Float current tests
Results: 3.5 volts was selected as float voltage, float current was measured at 0.003A.

4) Ragone Plot from cell capacity measurements at 0.1C, 0.2C, 1C, 2C, 4C, 10C
Results: The Ragone plot looked good - power roll over was at about 1000 W/l, or 600 W/kg

5) Spectral Impedance
Results: The ESR was consistent with the ohmic measurements. The results will be compared with the end of life after cycle testing.

6) Over Charge Abuse Test at 1C rate to 12V
Results: Cell vented at 111C at 11V - Open-circuit at 120C - No fire - Max Temp was 160C

7) 1C Capacity at temperature -40C, -20C, 0C, 25C, 35C
Results: Capacity at -40C is very low (0.3 Ah), -30C ( 4.7 Ah), -20C (6.3 Ah), 0C (7.3 Ah), 25C (9.8 Ah), and 35C (10.4 Ah) Recharge for -20C and lower is very slow.

8) Cell Utility Cycle Test - This test is at 50% SOC and the cell is charged and discharged at the 4C (40A) rate for 1.5 min.

Results: The cell will cycle nearly 1000 cycles before reaching the end voltage of 3.65V, then capacity is measured. At present, the cell is approaching 5,000 cycles. Capacity is slowly fading. Operating temperature is about 30C.

Summary:
Test results look good
------------------------------------

Sandia National Labs
Power Sources Development Dept.

 

[fechter]

8) Cell Utility Cycle Test - This test is at 50% SOC and the cell is charged and discharged at the 4C (40A) rate for 1.5 min.

Results: The cell will cycle nearly 1000 cycles before reaching the end voltage of 3.65V, then capacity is measured. At present, the cell is approaching 5,000 cycles. Capacity is slowly fading. Operating temperature is about 30C.

Cool.
What does that mean about the end voltage of 3.65v? What happens to the voltage after the cell gets too many cycles?

What I'm getting at is there a way to asses the health of a cell by some measurement other than running a full cycle test?

 

[D-Man]

Yeah, how can this be a "real world" test if its just a non-stop "marathon." What about longevity, shelf life, and the effects of rising and falling fluctuation temps over time. You can't draw conclusions on just a non-stop marathon. No one is going to be e-biking 24 hours a day in perfect temperatures. Also, Looks like the capacity tests for ambient temps has the same % drop as sla.

 

[Ypedal]

Shelf life and durability over real world use will take a long time, I don't feel like waiting 10 years to find out either.. so this is all good news !


5000 cycles even at that depth of discharge sounds good to me.! 8) Specially if you consider the 500 cycles i'm told i will be lucky to acheive with my LiMn packs under perfect conditions after 2 or 3 years !

 

[fechter]

Dman has a point about all this testing not telling us much about calendar life. It would suck, for example, if they lasted for 2-3 years whether you cycled them or not. But I'm with Ypedal, these results are impressive. Most batteries will totally crap out after that kind of marathon cycling.

 

[Battboy]

Warranty on Bob & Gary's e-bike packs is Two Calendar years.

Best,

Don Harmon

 

[Jeremy Harris]

Interesting, but that cycle depth is misleading in my view, as it's a very, very long way from real world EV use. We all know that the relationship between depth of charge/discharge cycles and number of cycles obtained through life is very non-linear. If you run pretty much any secondary cell at shallow cycle depths you will get massively extended life. For example, my Prius will get many millions of cycles from it's NiMH pack, but each of these cycles will only be between 40% and 90% SOC maximum, many will be a lot shallower. We all know that cycling NiMH over deeper ranges kills the cells in a few hundred cycles, so this graphically illustrates the non-linearity of life versus cyclic charge/discharge depth.

As far as I can see, the cyclic testing of these LifeBATT cells is only charging and discharging the cells over a 10% range at around 50% SOC. This is significantly less than the conservative charge/discharge control regime used in the Prius, so one would expect these cells to last many thousands of cycles when treated like this. In fact, if they are as good as NiMH, then I would think that they should last a few million cycles under this sort of cycle regime, so I would be disappointed if they didn't do at least 100,000 cycles, preferably far more.

In EV terms, this 10% testing is equivalent to buying a battery TEN times bigger than you need, and only ever using ONE TENTH of it's capacity before you re-charge it. My guess is that even the cheap Chinese cells will last a long time if treated like this. In all probability, cell calendar life degradation would have a far greater impact than cyclic charge/discharge degradation for such a shallow cycle regime.

The really telling test will be the results of your deep charge/discharge cyclic testing, running cells between about 5% and 95%, or thereabouts. I look forward to seeing those in due course, as they will most probably set a real world benchmark figure for us to compare these cells with others. The results from that test will give us a reasonable way of predicting real world life on an EV, unlike the shallow cycle tests done so far. Until then the cycle figures for the shallow tests mentioned above don't tell us anything meaningful, I'm afraid.

Jeremy

 

[recumbent]

We've see a few solid numbers in places we need to see them, for example: the Ragone plot looked good at 600w/kg which is a very important test parameter for RC guys.

Another good number is temperature abuse, granted it's rough science but important when your 25 KMs away from home, middle of August and your pulling lots of amps, it passed with flying colors, 112 Celcius at 11volts, plenty durable 8)

Lastly, Lithium cell chemistries have a 10+ year shelf life, listed in many places. Double anything out there.

I think these cells are lookin just fine, lets lower the price, how bout $35 per cell, in March, and we'll all buy double size orders and less warrantee issues cause we'll only do partial discharge and our batteries will last 8 years +, that would be sweet. 8)

Lets get them out in the market place Don Harmon and adjust the web site to reflect new prices to sell lots of them.

 

[drewjet]

Don,

Those specs look good. Thank God I live in Florida and don't have to worry about -20C temps.

I think a much more useful and realistic life test would be 80% DOD cycles at 10 C discharge with 1C Charging.

 

[safe]

Lastly, Lithium cell chemistries have a 10+ year shelf life, listed in many places. Double anything out there.

Is that a fact?

I did not know that and thought that after a few years the Lithium cells would die just like all the rest.

Any links of proof about that?

That's great if true... then you would want to buy a bigger pack and get longer range and longer life. Very cool. 8)

Buying the bigger pack is not such a negative because calender life is not such an issue.

Let's see... if I buy the Thundersky cells from Patrick and get at least 50 miles per ride (that's half the capacity) and then go for 5000 cycles that's 250,000 miles stretched out over 10 years... 25,000 miles per year. That's a lot of riding. (effectively infinite) I'd be satisfied with 5,000 miles per year and 50,000 miles lifespan... one fifth of the theoretical limit. $1000 divided by 10 years is just $100 a year for "gas" so to speak.

LifeBatts use a smaller form factor and make more sense on a regular bicycle. I'm going to have to build a special frame to hold the Thundersky cells.

 

[Jozzer]

Thundersky's arn't lifebatts though, Lifebatt seem to be much higher quality, and A123 higher still. I'd bet shelf life AND cycle life is higher on lifebatts, and even higher on A123's than thundersky's...

 

[Ypedal]

The lithium cobalt battery in my cell phone dies every 3 years pretty consistently..

I'm told Lithium Manganese has a 2 to 3 year service life if the C rate is kept in check.. remains to be seen, i'm on year 2 now.

Lithium Iron, god knows as it's only been out a few years.

 

[Battboy]

Thundersky's arn't lifebatts though, Lifebatt seem to be much higher quality, and A123 higher still. I'd bet shelf life AND cycle life is higher on lifebatts, and even higher on A123's than thundersky's...

A123 can achieve such high discharge C-rates. ( please note; ONLY during discharge, the charging performance is not so impressive = 1C)

PLEASE NOTE;

That most of the time you will not run into that the LiFeBatt cells will NOT limit the performance, 20C discharge is a hell of a lot, and 3C ( 20 min) charging is astonishing. You can throw all this discharge / charge data out if you DO NOT have a battery management system ( BMS) that can match the performance of the cells.

This rules as well for A123, they also have to build complete systems, and then you are looking at way lower performance. Within LiFeBATT we do have high power BMS that can deliver huge power, but they come with a HUGE price tag.

This is the sort of catch 22 situation that we are all facing, A123 sort of have a “Super-charged motor” but no “Car” to put it in.

As well, do not get carried away with the “tech porn” that they all throw at you, why on earth do you need 100C discharge rates for…. rockets ?

Look at the applications and you will see, that EACH LiFeBatt cell can crank out 200 Amps peak, and I repeat that is THE CELL.

So do not get disappointed / surprised when you see the Discharge / Charge rates for the new hard-packs. I could not spot any big heat sinks so my guess is that the hard-packs will not be able to utilize the total 20C rates that the cells can perform, BUT the important thing is that it is a –Plug and Play – product, something anybody will be able to integrate into their products. And THAT is HUGE, a SELLABLE PRODUCT, right here right now.

Don Harmon

 

[Jeremy Harris]

Just in case my last post was interpreted as criticism, I'd like to assure everyone that it wasn't meant that way.

I was just pointing out that shallow depth cycle testing doesn't give a meaningful indicator for real world EV use cycle life.

From all I've read so far, I suspect that the LifeBATT cells are as good as other makes of LiFePO4 cells that we know work OK, like the A123 and emoli cells. Like any new product it will take time and experience to establish a reputation.

It would be really useful if we could gain some solid, objective, evidence on the real performance of all the various flavours of LiFePO4 cells out there. In particular, being able to trade between cycle life, performance, reliability, calendar life and price, using real understanding rather than just guesswork, would be useful.

My best guess is that the "best" battery for most of us may not be the most expensive, or the one with the longest cycle life, if we worked out just how we were going to use the battery through life. Mind you, it might not be the cheapest either, especially if reliability was questionable.

Jeremy

 

[safe]

You can tell by looking at my bike that my strategy has been to use larger batteries (bigger capacity) and then run them at less than their breaking point. My feeling is that it's the perpetual need to push things to their limits that is degrading the life of these batteries. You need a BMS (either automated or manual like with an observable cell voltage monitoring system) for the discharge side and you also need to balance on charge. The two systems can be separate or combined into one system.

My guess is that a system designed for 10C that is always run at 10C will wear out pretty fast if you also discharge them fully no matter how carefully you manage them.

A battery designed for 10C that is run at 5C (or even 1C) and not completely discharged with each cycle will likely last as long as the longest calender life of the batteries allows.

It's all about proportions... it's always better to have MORE battery than less as far as lifetime. I've found this to be true with SLA already and have gone a lot further than I initially had hoped.

When it comes to batteries you actually don't save money over the long term by using the smallest battery capacity. There's a "perfect size" for longest life and lowest price and most people tend to miss on the low side of the curve. The peak of the cost-benefit relationship is usually about double what people first desire based on the C rating. People need to get bigger battery packs... this is just reality.

(good news for LifeBatts and others )

 

[Frxdy]

I'm going to guess the 10 yr shelf life is for lithium batteries.... not recgargeable lithiums. Just recently I bought some lithiums for a remote control temperature gauge. A yr ago they were rated 8 yr shelf life, now I see they are rated at 15 yr shelf life. The non-rechargeable lithiums and the rechargeable lithiums are so far apart scientifically I wish they would call one of them something else!

 

[TylerDurden]

Re-thiums.

Gung Hay Fa Choy!!!!!!!

 

[recumbent]

I got the "ten year lifespan for lithiums" you guys are quibbling about, from this site: http://www.mpoweruk.com they call them "primary cells" but the site is mostly about rechargable batteries. I've seen it written elswhere, also, if stored properly. For litiums: is 40% charged in a cool place seems to be the accepted norm. My cell phone is 6 years old and still going.

IT would be nice having a stable chemistry to work with for a change, I think we have it finally with Lifepo4 cells.

 

[farmer]

Hi Don,

You mentioned LifeBatt stocks a few posts back. Do you have investment information on LifeBatt? What stock exchange? Ticker symbol?

Thanks!
Farmer