2.5USD per Ah for 15Ah and 20Ah 30C cells

[cell_man]

Guys,

Tests are still pending for these cells. As data becomes available it will be made available. If all goes well packs could be starting to despatch next week.

If anyone else wants to get some test cells to abuse please let me know as there will be a quantity of cells from the main batch here within a couple of days in addition to some of the orinal samples. Will make some efforts to get some test figures on the cells already here tomorrow. It's driving me crazy having these cells here and not having the required load to test them fully....

I've got 2 * 2ohm loads so I may have a play tomorrow and see if I can come up with any meaningful data. Hopefully I can visit a battery pack supplier that I've met with before to run a few tests on these cells tomorrow also.

Price will be 2.5USD per Ah for bare cells Maybe some small additional fee for pack assembly and materials to be determined. Packs will start shipping once I've confirmed the specs, so hopefully sometime next week. So 50USD per 20Ah and 37.50USD per 15Ah. Shipping at cost and as cheap (but good) as can be found.

No need to mention any specific battery manufacturers please Any questions please fell free and PM me if you want to chat.

Thanks
Cell Man

[nieles]

what Chemistry are these cells? lipo or lifepo4?

also where are you located? (for shipping)

if you are in europe i would like to test some cells for you!

Niels

[Ypedal]

we like open discussion here..... lol..

What format cells ? 18650, prismatic, cylindrical, foil pouch ?

chemistry ? limn, lifepo4, etc..

And we got plenty of power users on this forum.. no shortage of that

[lynchy]

.

[lynchy]

.

[cell_man]

These are prismatic cells with the following dimensions and weight

Capacity: 20Ah Capacity: 15Ah
Size: 7.0X 166X227mm Size: 6.8X 150X211mm
Weight: 480g Weight: 400g
3.3V nominal

Independent tests will be forthcoming soon. Will also put my own test data up in the next few days as it becomes available.

The 30C figure is just an estimate from the limited available information available. Tests will confirm actual vaues very soon.

Will ship from China. Happy to let some sample cells go for independent tests once we're happy they are to spec.

[Ypedal]

is this a double personality disorder ?

[cell_man]

It's late here now so I'll respond to any subsequent posts in a few hours. I'm sure some others will chime in shortly

I don't really want to discuss branding and these cells will be delivered without any identifying marks. This is a big forum and similar cells can be discussed on different posts. Pics confirming sizing and test results etc will follow. Hope to start shipments next week once tests have confirmed specs.

[cell_man]

I don't know what you mean...

These cells will perform or they will not be released.

I feel a little discretion is required

Feel free to drop me a PM and we can have a chat.

[thomas]

Is this the price for 1 cell?

Whats the price for ex. 400 20Ah cells, the same?

[CroDriver]

Hi.

I would like one 20Ah and one 15Ah.

Where are you located?

PayPal, wire transfere...?

[johnrobholmes]

This either needs to be a sale thread, or tech thread. If you plan to sell them you need a thread in the for sale subforum, I can move this thread there if you wish.

[cell_man]

John,

I'm sorry for posting in the wrong section. Please move it to the appropriate section as you see fit

Hi.

I would like one 20Ah and one 15Ah.

Where are you located?

PayPal, wire transfere...?

Paypal is probably best but I need to sort a couple of things first but any charges will need be added. Can drop me a PM and we can have an MSN chat or something

Is this the price for 1 cell?

Whats the price for ex. 400 20Ah cells, the same?

Thomas, we need to have a bit of a chat but to be honest there isn't a huge margin in them at the price I have set. we would need to discuss this on MSN/Skype or something.

[Doctorbass]

is this a double personality disorder ?

Maybe asking directly...

Lynchy , are you also Cell man ??

Doc

[liveforphysics]

Yes. (as you can of course see from IPs)

And the cells are also the world's most respected brand in LiFePO4.

However, as we well know, this brand has strict policy about not permitting it's bare cells to be sold to the public, so precautions/discretion needs to be taken to keep the availability of these cells to the public where they can help advance the grass-roots EV moment.

This is a tremendous value for premium LiFePO4, and doing it this way will let this excellent value be available indefinitely.

[Ypedal]

My biggest concern is how they make it out the door.. are these the real deal, 100% perfect consistent cells, or the one's that don't meet QC for the big contracts ..... either way if they perform even near what is being wished for i'd be one happy camper to strap on a bunch for my Agni 95 motor and 72v 500amp controller !

Having had my fair share of early batches of all sorts of stuff and found layers of glue residue under shrink wrap layers with x of y hacked up into sub-packs proving recycled rejects or that kind of jazz ( trying to build a quality pack from mis-matched cells is a bitch ).... i'm reluctant to jump for joy .. but all that said i anxiously await the detailed specs from trusted sources !

[cell_man]

Cells arrive in a white plastic tray as they come from manufacturer. These stack together and will be used for shipping if the cells are not built into a pack. These are not damaged or seconds in any way. Discussions are already underway to get some sample units out to a few trusted people that can run their own tests. Some have already been sent.

I'm now informed 100pcs (50 of each) will be sent for final approval, arrive about Monday or Tuesday next week. Should be a nice Christamas present The full batch has arrived and is undergoing checks to ensure they are all 100%. I still have a few of the original sample pieces and would be happy to send 1 or 2 of these to a respected knowledgeable person for some independent tests. Cells will be marked with test parameters and I should have some typical test parameters soon from the batch now undergoing tests.

I have a cell charger/discharger on the way and a big resistive load. I've paid a bit extra to get the loads here tomorrow and will run some tests over the weekend.

There's no rush for anyone to throw money at me right now, just get Cristmas and maybe New Year out of the way and the tests should have verified the cells by then. There is a lot of interest from some big buyers but will keep some back for some at least. There should be future batches so even if you miss the boat this time around things are in place to ensure future batches will be made available. I'll try to ensure that end users can get access to these even if big customer wants the lot. I could offer something like a small refundable deposit if it's required, to put aside some cells who is really keen to guarantee some cells. I'm not ready to do this quite yet but will have something in place soon.

By the way what is the going rate for the cell log 8S and icharger 208B. I'm gonna see what they will do for me and could maybe source these in quantity and could put some of these in with the packs if people thought that would be of interest I'm going to get some samples sent to me today as I think they'll be very useful for my testing. They want a lot of money for retail price What's the norm for 1 or 2 pieces from them? Would you guys recommend going with the P350 charger that they also sell?

[cell_man]

SIZE(mm) MAX S NOM CURRENT MAX CURRENT BALANCE A MAX CHARGE A CHARGE/DISCHARGE
116*97*30 16S 80A 100-160A 200mA 20A Separate
125*120*30 20S 100A 120-180A 200mA 30A Separate
160*153*30 24S 100-300A 400-600A 200mA 300A Separate/Share

Here are a few examples of some high power BMS that are available.

[GGoodrum]

SIZE(mm) MAX S NOM CURRENT MAX CURRENT BALANCE A MAX CHARGE A CHARGE/DISCHARGE
116*97*30 16S 80A 100-160A 200mA 20A Separate
125*120*30 20S 100A 120-180A 200mA 30A Separate
160*153*30 24S 100-300A 400-600A 200mA 300A Separate/Share

Here are a few examples of some high power BMS that are available.

High power?

It just kills me that the Chinese BMS variants have current limits at all. There really is no need for this, especially with 30C cells. Controllers have current limits, why on earth do you need one on a BMS? I guess the early units that came with the "duct tape" packs, they needed to limit the current to 20 or 30A, because the cells were so weak that's all they could handle, so a "standard" 40A controller could damage the cells. Since then, the cells have gotten a lot better, but still they include a current limit. Now it would appear they are extending a bad practice by having versions with 200-600A current limits. Why on earth would you need this? Typical inside-the-box thinking, if you ask me. This is just plain ridiculous

Another pet peeve I have with these is the woefully wimpy shunt/balance current. Having a BMS that can be charged at 30A, much less 300A, implies these are to be used with higher capacity setups used on larger EVs, and yet they still can only manage 200mA of balancing current? For anything larger than an electric skateboard, it will take days to balance the cells at that rate. We use 750mA on bikes, and I can't imagine anything less than 1A for a motorcycle, or anything with 80Ah, or more, maybe 2A.

Anyway, I'm done.

[olaf-lampe]

what Chemistry are these cells? lipo or lifepo4?

also where are you located? (for shipping)

if you are in europe i would like to test some cells for you!

Niels

Try to ask Martijn from allgreenvehicles for these cells. He is located in Oosterhout, NL and has plenty of stock

-Olaf

[cell_man]

SIZE(mm) MAX S NOM CURRENT MAX CURRENT BALANCE A MAX CHARGE A CHARGE/DISCHARGE
116*97*30 16S 80A 100-160A 200mA 20A Separate
125*120*30 20S 100A 120-180A 200mA 30A Separate
160*153*30 24S 100-300A 400-600A 200mA 300A Separate/Share

Here are a few examples of some high power BMS that are available.

High power?

It just kills me that the Chinese BMS variants have current limits at all. There really is no need for this, especially with 30C cells. Controllers have current limits, why on earth do you need one on a BMS? I guess the early units that came with the "duct tape" packs, they needed to limit the current to 20 or 30A, because the cells were so weak that's all they could handle, so a "standard" 40A controller could damage the cells. Since then, the cells have gotten a lot better, but still they include a current limit. Now it would appear they are extending a bad practice by having versions with 200-600A current limits. Why on earth would you need this? Typical inside-the-box thinking, if you ask me. This is just plain ridiculous

Another pet peeve I have with these is the woefully wimpy shunt/balance current. Having a BMS that can be charged at 30A, much less 300A, implies these are to be used with higher capacity setups used on larger EVs, and yet they still can only manage 200mA of balancing current? For anything larger than an electric skateboard, it will take days to balance the cells at that rate. We use 750mA on bikes, and I can't imagine anything less than 1A for a motorcycle, or anything with 80Ah, or more, maybe 2A.

Anyway, I'm done.

It's not all bad GGoodrum. If they got it 100% all of the time there wouldn't be any room for innovation from people like yourself. The above is only some options that I have available and maybe good enough for some users and will be enough to get them started. If they prove to meet the specs then it may be a good option for some. I'll happily just get the pack built for whatever BMS the user wants to use. These cells are apparently very easy to assemble and just require a special PCB to enable a nice secure way to series up the cells, which will be supplied whether self build or pre assembled. There is no current flowing through the PCB other than for BMS signals/charging. If people want to use your BMS I'll make the necessary connections as required, no problem

I've spoken with Hill RC and will have some prices on their kit and they are happy to do custom builds for a reasonable sized batch. So that could be another option but I need to get to Shenzhen to discuss, maybe can in about 2 or 3 weeks.

I've got a 208B charger/discharger, 350W PSU, 2 * cell log8s and 20 * 0.1ohm resistors/switches/bus bar etc arriving tomorrow. The test parameters for the cells under test should be with me tomorrow and each cell will have paramets marked on them. I hope to confirm these myself next week when I receive the preliminry batch. Testing of the samples I have here will be done over the weekend.

Cheers
Cell Man

[liveforphysics]

It just kills me that the Chinese BMS variants have current limits at all. There really is no need for this, especially with 30C cells. Controllers have current limits, why on earth do you need one on a BMS? I guess the early units that came with the "duct tape" packs, they needed to limit the current to 20 or 30A, because the cells were so weak that's all they could handle, so a "standard" 40A controller could damage the cells. Since then, the cells have gotten a lot better, but still they include a current limit. Now it would appear they are extending a bad practice by having versions with 200-600A current limits. Why on earth would you need this? Typical inside-the-box thinking, if you ask me. This is just plain ridiculous

Another pet peeve I have with these is the woefully wimpy shunt/balance current. Having a BMS that can be charged at 30A, much less 300A, implies these are to be used with higher capacity setups used on larger EVs, and yet they still can only manage 200mA of balancing current? For anything larger than an electric skateboard, it will take days to balance the cells at that rate. We use 750mA on bikes, and I can't imagine anything less than 1A for a motorcycle, or anything with 80Ah, or more, maybe 2A.

Anyway, I'm done.

Agreed Gary. The cells should have a direct connection to the controller with nothing in between. The BMS should be there to balance cells, and the LVC should be done by a simply turning off the ACC lead to the controller, or better yet, a first stage pre-LVC that activates a little LED on a pigtail you can tape to your handlebars or dashboard, then when it reaches full LVC, it just turns off the turn-on (ACC) wire to the controller. The charge input can go through BMS through a FET that turns-off if any cell goes above the HV limit.

There is zero need for shunts, or big FETs in a BMS. This makes for not only better functionality, but better performance and a more compact package as well.



If you're going to charge at 20-100amps, you've gotta have a minimum of 1-5amps balance shunt current, or you may as well not be balancing.

[JRP3]

I wonder how much balancing is really going to be needed. If these cells are top quality they should all have the same capacity and internal resistance. Just under charge slightly and don't discharge completely and no single cell should go too low or too high.

[RoughRider]

do you have new test results?

[liveforphysics]

I'm watching the tracking numbers. Cells are still in transit from China to Seattle.
Tests will happen once I get the cells.

-Luke