72V LiFePo4 Question

You sound pretty overly-defensive to me, and especially when i was right on the verge of changing my mind about lifebatt. =] Honestly i don't have any "loyalties" one way or the other, i'm going to be building a full-scale e-motorcycle in a few months and I want to be absolutely as well informed as I can possibly be, which is why i'm doing all this r&d beforehand. As a mech-engineer student, this is the hard part for me (learning about electronics), the building and such is the easy part. So I'm not really trying to argue one way or the other, i would just like to figure out why there inconsistencies in my understanding of whats going on (as opposed to assuming that these inconsistencies are an indication that one manufacturer is being misleading).

NOT REALLY, JUST TRYING AS ALWAYS TO BE COMPLETELY HONEST AND MAKE CLARIFICATIONS THAT ARE NEEDED.

However, in the spirit of argument, to which I will always enjoy, here are my "quirks"
For starters, the lab tests page om the lifebatt site is not up. If its not up, there really shouldn't be a tab, just add the tab later.
Second...is there a place where it says nano? I hate to categorize, but other then checking out the website of the place you say is the supplier, theres no way to know.

THE FULL REPORT HAS BEEN DONE NOW FOR OVER TWO WEEKS. I WANT TO PUT IT UP ON OUR WEBSITE BUT I CAN'T UNTIL IT'S OFFICIALLY SIGNED OFF AND PUBLISHED BY SANDIA ON THEIR WEBSITE. IF YOU SEND ME AN EMAIL I WILL BE HAPPY TO FURNISH YOU A COPY BUT YOU CAN'T PULISH IT. WE DON'T WANT TO GET ON THE WRONG SIDE OF THE DEPT. OF DEFENSE. WRITE TO: DON [at] LIFEBATT.COM

I did find a bunch of new info by digging through the pdf. 60% of capacity at 10C The a123 graph shows about 99%+ retained capacity at 10C and above.

I DON'T DISPUTE THERE ARE SOME DIFFERENCES HOWEVER OVERALL A123 ARE CLOSE IN SPECS. LIFEBATT'S CHEIF SCIENTIST WAS INVOLVED IN A123'S ORIGINAL BATTERY DESIGN.

The 7C graph appears OK, but it only goes up to 250 cycles.

IN THE SANDIA TEST USING A PSOC PROTOCOL FOR HEV TESTING THE LIFEBATT CELLS EXCEEDED 8,900 CYCLES ALEIT AT A FAIRLY SHALLOW DISCHARGE. WE HAD NO CONTROL OVER THE PROTOCOL SANDIA USED AS THEY WERE PRIMARILY TESTING FOR HEV USE.

The "Burst" capacity on the a123 site is "over 100C" however they don't specify the length of the time where as yours is listed at 40C but the time IS listed..18s.

YOU MIGHT WANT TO LOOK AGAIN: MAXIMUM DISCHARGE CURRENT IS LISTED AT 140 AMPS FOR AN 18S PULSE. A123 LISTS THEIR PULSE DISCHARGE AT 120 AMPS FOR 10S.

The maximum continuous current for one 72gram a123 cell is 70A
the maximum continuous current for one 359g lifebatt cell is 120A

so relative to eachother...359g of a123's is 359/72 = 4.98 * 70A = 350A
So while by weight, a123's can deliver 350 continuous, lifebatt can only deliver 120A

HAVE YOU CONSIDERED THE AMP HOUR RATING ON A SINGLE A123 M1 CELL IS 2.3 AH WHILE THE LIFEBATT 40138 CELL IS 10 AH ? IT WOULD TAKE 4-5 OF THE A123 CELLS TO EQUAL 1 LIFEBATT CELL.

Anyway, for similar pricing, it would be nice to know how big these differences in performance really are. Not that I would actually buy a123's now anyway because of the high price and lack of bms/charging ability, but it could be useful in the future. I already have someone designing a pack balancer, i may extend that to a bms or cms for future models.

www.lifebatt.com

AGAIN, ALL YOU CAN BUY FROM A123 ARE DEVELOPER'S CELLS.

BEST,

DON HARMON

Hey Don,
Just a few more questions,
Did you mistype the specs on that HPS-7210? The website says L14.33 x W7.17 x H 6.36inch 18lbs. It's pretty important if I am going to fit 2 into my existing battery frame.

YES, THANK YOU FOR CATCHING THAT ! THE CORRECT SPEC. SHOULD READ: L. 14.33" X W. 7.17" X H. 6.36". WEIGHT = 27.7 LBS.

As for the controller I have a Alltrax AXE7245 that is programmable so I think it can high and low voltage cut off. Do you know anything different or had any bad experiences with this controller?

I KNOW THE NAME THAT'S ALL. NO PERSONAL EXPERIENCE WITH THEM. SOUNDS LIKE A HIGH END CONTROLLER SO IT SHOULD BE FINE.

I would feel better getting everything from one supplier(with warranties) so if I got 2 of your 36V chargers would i have to disconnect anything to charge or just plug it in and forget it until I ride again?

WE WILL HAVE A 72V CHARGER AVAILABLE SOON WHICH WILL BE OFFERED IN REGULAR OR SPEED VERSIONS LIKE THE OTHER CHARGERS WE OFFER NOW. THIS PAGE IS ALSO NOT UP ON OUR SITE AS I HAVE BEEN WAITING UNTIL IT IS COMPLETE TO PUT IT UP.

I would love to be riding right now but for $200 I think I can wait until July since 2 weeks would be mid June anyway.

ONE OTHER CHANGE I MUST REMEMBER TO MAKE IS THAT OUR STOCK OF INVENTORY WILL NOW BE DELIVERED IN SEPTEMBER, NOT JULY - HOWEVER ALL PRODUCTS ARE STILL AVAILABLE FROM OUR FACTORY IN TAIWAN. IT DOES HOWEVER MEAN YOU WILL HAVE TO PAY UPS AIR CHARGES WITH ORDER.

BEST,

DON HARMON

www.lifebatt.com

Hi from Germany,
I am new here, but i am reading in this forum for quite a while.

I purchased 2 36v 20Ah Lifepo4 batteries and connected them in series for 72v in order to use it for a x5304. The controller should work until 48amps.

I have the following problems:
- I was only able to get at most 2000 watt out of the packs, then probably one of the BMS cut off
- Out of the 20 Ah on the first ride I got only 6 Ah out with constant cut offs towards the end at decreasing watts (cut offs at around 400 watts in the end was when I stopped running the vehicle)
- Charging them did not work afterwards

I got the hint that may be some of the cells are out of balance, so i should run them empty on very low power. I did that with one of the packs seperately at 36v and it worked until a total of 14.3 Ah (which seems okay for the first charge)and charging this pack works now fine. BUT the second pack did not do anything, even the braindrain control unit showed nothing and charging is not possible.

What can I do? Is this one pack dead?? (I hope not!)

Regards,

Thomas

What vendor sold you the batteries. Ping says not to do what you did if it was him.

Well, If it helps you to help me solve the problem...

yes, Ping said he does not recommend them to put them in series. So if I can blame anyone for it its myself, I am aware of that...but this itself does not solve the problem, right?

No it doesn't, but I was fishing for info that may help one of the smarter folks help you. As I understand it, from other posts, if your ping bms cuts out on one battery, it may fry the bms on the other. Ping is rumored to have new bms coming that won't have this problem so maybe you can get one of those to replace it if you have a fried bms. I doubt the battery is damaged unless something looks melted on the pack. A voltmeter can be used to read each cell and find the bad one if you do have problems with cells. The only test I know for the bms is the does it look burned visual inspection. Another option that may work for you would be to sell off the good cells and try again with a new battery. The community would be likely to snap up the loose cells. Good Luck!

The pack looks perfectly fine, no smell no nothing. The BMS is the same...nothing black, nothing burned, no smell...

Thanks already for the hint with the new BMS from Ping, the testing of the cells I will try tomorrow.

Is there anyone who experienced the same or knows a method how I could make the pack working again?

But just for those who are thinking about Ping batteries: IF you use them as supposed, things should work fine ;-) How their long term performance is I cannot judge at he moment.

I believe endless sphere has some threads about repairs to duct tape batteries. I don't recall any on testing the bms, but there are many many pages to read over there. You may be able to attract more help here by starting a new thread instead of continuing this one.

I did find a bunch of new info by digging through the pdf. 60% of capacity at 10C The a123 graph shows about 99%+ retained capacity at 10C and above. I DON'T DISPUTE THERE ARE SOME DIFFERENCES HOWEVER OVERALL A123 ARE CLOSE IN SPECS. LIFEBATT'S CHEIF SCIENTIST WAS INVOLVED IN A123'S ORIGINAL BATTERY DESIGN.

The 7C graph appears OK, but it only goes up to 250 cycles.

IN THE SANDIA TEST USING A PSOC PROTOCOL FOR HEV TESTING THE LIFEBATT CELLS EXCEEDED 8,900 CYCLES ALEIT AT A FAIRLY SHALLOW DISCHARGE. WE HAD NO CONTROL OVER THE PROTOCOL SANDIA USED AS THEY WERE PRIMARILY TESTING FOR HEV USE.

*awesome, this is great news for the longevity of the batteries*

The "Burst" capacity on the a123 site is "over 100C" however they don't specify the length of the time where as yours is listed at 40C but the time IS listed..18s.

YOU MIGHT WANT TO LOOK AGAIN: MAXIMUM DISCHARGE CURRENT IS LISTED AT 140 AMPS FOR AN 18S PULSE. A123 LISTS THEIR PULSE DISCHARGE AT 120 AMPS FOR 10S.

*its not fair to compare a 359 gram cell with a 72 gram cell....thats why I have the comparison below*

The maximum continuous current for one 72gram a123 cell is 70A
the maximum continuous current for one 359g lifebatt cell is 120A

so relative to eachother...359g of a123's is 359/72 = 4.98 * 70A = 350A
So while by weight, a123's can deliver 350 continuous, lifebatt can only deliver 120A

HAVE YOU CONSIDERED THE AMP HOUR RATING ON A SINGLE A123 M1 CELL IS 2.3 AH WHILE THE LIFEBATT 40138 CELL IS 10 AH ? IT WOULD TAKE 4-5 OF THE A123 CELLS TO EQUAL 1 LIFEBATT CELL.

*yes i understand that it would take 4-5 a123 cells to equal the amp hour rating of one lifebatt however 1 lifebatt cell is exactly 4.98 times heavier then 1 a123 cell...so in my mind, they are nearly equal on a weight basis, with the power advantage and extra cost leaning towards a123
on the plus side however, 10ah cells would be a lot easier to deal with then lots of 2.3ah cells in parallel*

www.lifebatt.com

BEST,

DON HARMON

Yes, I agree with you. Our 40138 Large Format cells also allow us to break down the Voltage Management into groups of (4) Cells. Since we end up with much fewer cells to manage we think this offers a simpler and better way to go with "battery management". Also our current cells offer the screw post ends which eliminate and solder connections and make our HPS Packs much easier to replace a cell should the Pack need servicing. One more thing I will mention is that we will have a 14 Ah Cell (same 40138 form factor) in production by the end of 2008. These will also fit all of our standard HPS Packs.

Best,

Don Harmon

My first post and just a FYI as to my experience.

I called so many so called "LiFePO4 dealers" as of March 08 and still do not have a battery.

I called and Emailed the following:

Foxx-spoke to owner once, then no call back(3 calls)
Yesa-paid for battery and have not received it(many communication via email)
Lifebatt-left two emails and 2 phone messages with Don Harmon on answering machine. NO RESPONSE. Now I see his name all over here. I won't do business with him.
Ping- no batteries left.
Ebikes.ca- None/However, very professional and helpful advice.

For your information we do not have an answering machine except on weekends and even then rarely it's on. So don't believe this poster when he says he's emailed us and called us. We answer all emails and all phone calls. This person is not telling you the truth and if he wants to call me my number is 702.804-2641. It is posted on our website: www.lifebatt.com

Best to all,

Don Harmon

I found it exceptionally easy to get in touch with Don

Don is tops in my book, too. :)

Sent him a message through his website and he personally replied within 24 hours. Doesn't get any better than that.

Thanks guys, this poster lives up to his handle and must have a hidden agenda ? LiFeBATT is always available to answer questions and replies to all inquiries. We can't always please everyone but we keep trying. I really am glad to see we have some support from the members here.

Cheers!

Don Harmon

Thanks guys, this poster lives up to his handle and must have a hidden agenda ? LiFeBATT is always available to answer questions and replies to all inquiries. We can't always please everyone but we keep trying. I really am glad to see we have some support from the members here.

Cheers!

Don Harmon

There is no hidden agenda here. I assume this is an unbiased forum as well and not owned by any battery dealers. If so, then I will take opinions here as truths. I am not going to research my phone records to prove to everyone that I called. The fact is, there were 2 phone calls to Lifebatt with no response. Further, I have not singled out Mr. Harmon either. I have posted my experience with all dealers I have dealt with.
I am willing to concede the fact that Mr. Harmon may be busy and is not able to return all calls as he admitted to in a previous post("We can't always please everyone but we keep trying". If he wanted to keep trying(as he stated in his post), then he should try to get customers business here after the bad experience instead of trying to bash the customer by saying there is a "hidden agenda". This is not only unprofessional but shows a lack of business savvy as well. This was his opportunity to correct a situation and he chose to be defensive. He should have offered immediate assistance but that is how I run my business and can't expect others to run their business the same.
I am not trying to bash lifebatt or Don Harmon. Simply put, this is obviously the only way to get a response from the LiFePO4 battery dealers by posting on a forum.

I am glad that some have had positive experiences and thanks for your input to your experience. This is my experience and hopefully my experience will be positive in the end. Again, as long as the opinions here are unbiased , then I am willing to concede that I have just been in the 1 percentile of companies dissatisfaction rate.

Thank you,

Anthony Saya

I have a friend who is an extremely good salesman. He is super passionate about his products and everything else he is involved in. People that don't know him well think he is an out of controll insane wildman! But those of us who know him well just undestand he is just enthusiastic to a degree those who don't know him are not used to. Give Don a break, he just loves his product. If he is like my friend he has about 200 iorns in the fire at once. I can handle maybe 2.

A word for Don, When you type all caps, you are screaming at us like a drill seargeant. So we think you are attacking then no matter what the words say. Personally I can't wait till your cells are everywhere. Maybe by then I can afford some. They are clearly worth the money. You've just had some roadblocks keeping you from selling them in a pack that is sised for ebikes. My purchase of duct tape was based more on avaliabilty at the moment than anything else, I needed 20ah, and Mr Ping had it. He made buying from him easy, and us customers like easy even more than low price.

Hi Dogman, There is something going on now that might be of interest to you and the other members on here. I won't get into the details here but you can check it out over at Power Assist: http://tech.groups.yahoo.com/group/power-assist/message/74478 It's a great way to get some quality packs @ a great price I think.

Best,

Don Harmon

Haha, drill sargent...It seemed to me he was using capitals within quotes as "answers" i would have thought it better to use bold or underline or something but it didn't bother me since i ended up using bold to respond.