12Ah 3.3V LiFePO4 cells on ebay

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flip_normal

100 W
Joined
Jul 12, 2007
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These on ebay look like Psi Corp 12Ah 3.3V LiFePO4 cells.

discharge rate 6.5C continuous ie. 80A on ebay (edit) 130A continuous Psi Corp spec.

3.3V x 12Ah = 39.6 Wh/cell

49Au$ = ~46US$ / 39.6Wh = 1.16 US$/Wh

Just to compare.

MILWAUKEE V28

28V x 3Ah = 84Wh/pack

80US$ / 84Wh = 0.95 US$/Wh

Headway LiFePO4 38120 cell of 3.2V 10Ah (Edited after reading Jeremy Harris' post below)

3.2V x 10Ah = 32 Wh/cell

19US$ / 32 Wh = 0.60 US$/Wh
 
Those are from the factory that makes "lifeBatt" cells. Depending on who you talk to or believe, they may be legit or slag from early runs.

:?
 
OOOH, More goodies to drool over.
I emailed the seller to see if there were more available and what shipping costs would be.
 
The current production lifebatt cells are rated 20C..

These 6C cells i beleive were earlier production runs, possibly from a different factory, they did not meet standards set by lifebatt , not the real slim shady..

All things considered however, an option like many others right at this point in time.
 
HMM, I thought that the LifeBatts had green heatshrink?
Who is it that has the batteries of that configuration in green?
(not that it wouldn't be easy to change the heatshrink to try to hide the actual source.)

Oh well. 6C is plenty for me, and the price seems to be pretty decent... and easier to hook up with the screw terminals; I'm tired of welding tabs already.
I'm going to keep an eye on them.
 
I'm not so sure how much these cells have to do with lifebatt except it's claimed the "cells are manufactured from the highest grade of cathode powder which is supplied by Phostech Canada".

The seller also says they'll include a spec sheet with each cell showing "its individual serial number listed along with its measured voltage and internal impedance".

Message sent to seller asking for details of internal resistance and dimensions, will post reply if/when I get one.
 
Just heard back from him on my query. He has hundreds of them available.

I replied, and recommended that he join up here, and pointed him to this thread. Maybe he will join and answer all of our questions.
 
I just got this reply from the ebay seller;

"This cell is a common industry standard 40138 size cell. That is it measures 138mm long and is 40mm diameter. The specification on these cells is that the internal resistance (impedance) is less than 6 milli ohms. I actually just measured the internal impedance of a cell which is sitting on my desk and it measured out at 2.2milli ohms."

So that means that these aren't the same as the 12Ah cells on the Psi Corp site since those are 155.6mm long.

They're also unlikely to be LifeBatt rejects, what with the extra 2Ah capacity in the same size cell, assuming sellers claims are accurate. I'd like to see what Docbass makes of these.
 
I strongly suspect that the seller is lying about the origin of these cells. To the best of my knowledge, the majority, if not all, of this type of cell are actually made in the Peoples Republic of China. Even the LifeBatt cells are made in the ROC, as are the other similar cells given in the link above.

Whilst I think some of the sellers observations regarding Chinese re-sellers are possibly true for a tiny minority, I'd be put off from dealing with him simply as he seems to be slagging off all Chinese re-sellers as his main sales pitch. We, on this forum, know full well that there are some very decent, honest and honourable Chinese re-sellers, with just one or two that seem to be a bit dubious. In my personal experience I've dealt with more dubious ebay sellers from the West than I have from China, in fact I've never had a problem buying anything from China.

If these cells turn out to be OK, then they will be much easier to use than the 38120 Headway cells that I've just purchased (which are 10Ah capacity, rather than 8Ah). I like the idea of the bolt connections. If the price was a bit more competitive then they would be a good deal - as it stands they are nearly double the price of the Headway cells ($1.16 per Ah, versus about $0.60 per AH).

Jeremy
 
Thanks for the clarification on the Headway 38120 10Ah capacity Jeremy, I missed it. That's an impressive 25% increase in capacity over the 38120 Headway cells Doc tested, I don't have any reason to doubt it but do you have any way of testing it, makes those Headway cells you got look even better.
 
flip_normal said:
Thanks for the clarification on the Headway 38120 10Ah capacity Jeremy, I missed it. That's an impressive 25% increase in capacity over the 38120 Headway cells Doc tested, I don't have any reason to doubt it but do you have any way of testing it, makes those Headway cells you got look even better.
Click to expand...

Yeah, really! If it weren't for the distance, (and another 60 or so of my own batteries to test in the next week)... I'd loan my CBA to make sure...
 
Headway do two versions of these cells, 8Ah and 10Ah. They were both independently tested here: http://www.zeva.com.au/tech/headway/

The testing seemed to show that the cells I have, the 38120L versions, actually had a 10.5Ah measured capacity against a 10Ah rated capacity. The difference between the "L" and "P" versions is in maximum discharge rate, the 38120L is rated at 50A continuous, 100A peak, the smaller capacity ones are rated at 80A continuous, 160A peak. As I'm using four cells in parallel per sub-pack, I can safely draw 200A continuous, 400A peak, which is adequate for my needs I think. Had I been looking for more current from the same pack configuration then I might have opted to go for the cells that Doc had samples of.

As soon as I'm in a position to do some testing I will, I don't want to unbalance my cells before I build the pack though, so will try and test them once I've built the pack.

Jeremy
 
I found that link to the zeva tests right after I posted above... Didn't know prior to that that they had two model numbers with two different capacities. Seems to me that the 10Ah types you got are better for 95% of our ebike needs than the higher current ones. Only the 'hot-rodders' who want maximum speed and acceleration with small, light packs should need the 100A cells. IMHO...Even with my 2 motors I wouldn't often stress out a 2p pack, much less a 4p .

They sure tempt me more than the 8A ones. My 5AH 32650 LiCo batts still slightly beat them for $/WH and are significantly lighter weight... But in strict terms of power per dollar, it is getting closer than anything before...and my LiCos are frustratingly fragile in terms of surviving even minor electrical accidents (and stupidities) that wouldn't bother either the Headways or the original subject of this thread. Which, by the way... The seller also has 10Ah rated batteries at $5 less (each) than the 12 AH ones listed on eBay.

I wish I could get a 'do-over' of the last 4 months. Spending a little more up front on LiFe would have saved me several hundred dollars worth of ruined cells and weeks of work and frustration.
 
These are legit cells, and they are definitely from BMI, the factory that makes the LiFeBatt cells. The factory actually has several "mixes". LiFeBatt chooses to use the one that puts out the highest power, but they have this other new mix that trades a slightly lower "C"-rating for more capacity. LiFeBatt has an exclusive arrangement for their cells, but not in every region in the world. These cells are a different animal. The Ozie guy selling these used to be involved with LiFeBatt, but like some others, had a falling out. Now he is going directly to BMI.

As for the colors, there's no shrink wrap on the cells. They are annodized/painted. The original LiFeBatt cells were green. The newer ones are grey. The factory will make them any color desired.

-- Gary
 
In which case that just confirms my original guess - these cells DO come from China, despite the Aussie vendor boud-mouthing Chinese vendors in his advert...............................

Seems a fairly daft way to advertise to me, especially as it's been relatively straightforward to show the origin of these cells. What's even more stupid is that these cells are most probably reasonably good, if they come from the same factory as the LifeBatt cells.

Looks like the Aussie guy has just shot himself in the foot, at least as far as those of us that prefer to buy from honest vendors. I certainly wouldn't buy from someone who advertises using misinformation like this.

Jeremy
 
Jeremy Harris said:
- these cells DO come from China, despite the Aussie vendor boud-mouthing Chinese vendors in his advert.......
Click to expand...

I guess that depends on whether you subscribe to the "One China" view, or not, but I take your point.

These cells seem even more suitable for ebikes than the Lifebatts, to me. Anyway, I'd be happy to lose a bit of power density for a gain in energy density...
 
Not sure what he is advertising, but the BMI factory is in Taiwan, not the Mainland, and BMI uses Phostech Canada powder, so there's no import issues.

-- Gary
 
Hmmm. On a side note ... Looks like I can get 26650 LiFePO4 bats (my cost) about $5.00 USD each (min $5000 order). That comes to about $0.71/Wh.

26650 LiFePO4 battery specifications:
Voltage: 3.2v
Capacity: 2200mAh,
Internal Impedance: ≤12mΩ
Weight: 69-73g
dimension: 26x65mm

Still not as good as this post ...

Headway LiFePO4 38120 cell of 3.2V 10Ah (Edited after reading Jeremy Harris' post below)
3.2V x 10Ah = 32 Wh/cell
19US$ / 32 Wh = 0.60 US$/Wh

That looks like an awesome price for LiFePO4!
I think this is the link ... http://www.endless-sphere.com/forums/viewtopic.php?f=14&t=3374&st=0&sk=t&sd=a
 
Last I heard Taiwan was still in the Peoples Republic of China, so I honestly can't see the difference. It's a bit like implying that California (or any other State for that matter) isn't really part of the USA.

His advert (on ebay) is essentially a bit of a rant against Chinese sellers. It includes quotes like:

"EnviroSafe are not some cheap, poor quality Chinese made cells which provide inferior performance and when you send your money to China (as so many people have already found out) you are ripped off and either not sent the product, or if you do receive the product you find it fails dismally in a short time and you are stuck when the manufacturer won't honor their warranty claims."

and:

"12Ah is a genuine minimum capacity and independant testing recently showed these cells will measure an actual capacity of between 12Ah and 13Ah. This is a far cry from cells from China which in the majority of cases do not live up to their stated capacities."

I've no doubt that, like the majority of Chinese cells, these are OK. I just happen to think that selling by slagging off other sellers is a bit unethical. Certainly I'd not buy from someone who advertises in this way, irrespective of the real quality of their product.

Jeremy
 
Knuckles said:
Hmmm. On a side note ... Looks like I can get 26650 LiFePO4 bats (my cost) about $5.00 USD each (min $5000 order). That comes to about $0.71/Wh.

26650 LiFePO4 battery specifications:
Voltage: 3.2v
Capacity: 2200mAh,
Internal Impedance: ≤12mΩ
Weight: 69-73g
dimension: 26x65mm

Still not as good as this post ...

Headway LiFePO4 38120 cell of 3.2V 10Ah (Edited after reading Jeremy Harris' post below)
3.2V x 10Ah = 32 Wh/cell
19US$ / 32 Wh = 0.60 US$/Wh

That looks like an awesome price for LiFePO4!
I think this is the link ... http://www.endless-sphere.com/forums/viewtopic.php?f=14&t=3374&st=0&sk=t&sd=a
Click to expand...

The new solderless kit I did for a123 packs, listed here, will work for these as well. :)

-- Gary
 
Jeremy Harris said:
Last I heard Taiwan was still in the Peoples Republic of China, so I honestly can't see the difference. It's a bit like implying that California (or any other State for that matter) isn't really part of the USA.
Click to expand...

When did you hear that? I'm afraid it's not, Jeremy. It's Taiwan (R.O.C.) which is not the same at all, despite the wishes of the mainland....

Washington doesn't have missiles aimed at California, AFAIK :mrgreen:

Miles
 
Miles,

Doesn't the "R.O.C" stand for "Republic of China" then?

If I've got this wrong, then I retract all I've written, as I have always assumed (which I know to be a dangerous thing) that Taiwan was actually a part of China, even if it is semi-autonomously governed (a bit like Hong Kong, I thought).

Maybe a better comparison would have been to compare it to the Isle of Man, or the Channel Islands, which remain part of the United Kingdom despite their own governance systems.

Jeremy
 
Hi Jeremy,

Taiwan is a completely autonomous entity despite the efforts of P.R.O.C (blocking their membership of UN etc.).

They had elections recently....... and, yes, China has missiles trained on Taiwan.

I agree that it's confusing to have Republic of China (Taiwan) and Peoples Republic of China (mainland China)

Miles
 
GGoodrum said:
Knuckles said:
Hmmm. On a side note ... Looks like I can get 26650 LiFePO4 bats (my cost) about $5.00 USD each (min $5000 order). That comes to about $0.71/Wh.

26650 LiFePO4 battery specifications:
Voltage: 3.2v
Capacity: 2200mAh,
Internal Impedance: ≤12mΩ
Weight: 69-73g
dimension: 26x65mm

Still not as good as this post ...

Headway LiFePO4 38120 cell of 3.2V 10Ah (Edited after reading Jeremy Harris' post below)
3.2V x 10Ah = 32 Wh/cell
19US$ / 32 Wh = 0.60 US$/Wh

That looks like an awesome price for LiFePO4!
I think this is the link ... http://www.endless-sphere.com/forums/viewtopic.php?f=14&t=3374&st=0&sk=t&sd=a
Click to expand...

The new solderless kit I did for a123 packs, listed here, will work for these as well. :)

-- Gary
Click to expand...

Oh I like this. Like what I did on the chopper forks - 12 a123 stick in compression. (see http://endless-sphere.com/forums/viewtopic.php?f=6&t=4160). But I don't see a spring on the main central compression rod (rod compresses bats but rod is in tension). Just add a spring (to accommodate cell thermal expansion/contraction) and that baby is a winner! Very nice work. And all set up for balancing too. Cool!

Gosh ... So Much Politics on this thread! How about we just call Asia ... "Peoples Republic of Capitalism" ... WTF!
 
I've asked for a quote on 20 cells, a 24 charger and a 36v charger - to make two packs to put in series for 60v nominal.

Mark
 
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