Valence 18650 cells

[dimitrib90]

Does anyone have any specs on these type of cells? Whats their discharge rate, burst rate, ah rating, nominal voltage, etc etc? I think we might be able to get a really big quantity!!

 

[MitchJi]

Hi,

http://www.endless-sphere.com/forums/viewtopic.php?f=14&t=3374&st=0&sk=t&sd=a&start=255#p87472

Valence 18650: (3.21V@1.21A), (3.10V@3.03A), (2.812V@10.76A)
IR(1C,3C)=60.4mohm
IR(1C,10C)= 41.7mohm

Valence 26650: (3.18V@3.12A), (3.10V@6.11A), (2.73V@21.24A)
IR(1C,3C)=26.8mohm
IR(1C,10C)=24.8mohm

The 26650 would be better (much easier to build a pack using less than 1/2 the cells.

The ability to get a "really big quantity" is only useful if the price is very very good.

 

[oofnik]

I think we might be able to get a really big quantity!!

As in, you have an inside source and you want to know if people are interested in a group buy? Maybe?

 

[dimitrib90]

I think we might be able to get a really big quantity!!

As in, you have an inside source and you want to know if people are interested in a group buy? Maybe?

Not maybe, definitely. I am going to send the cells priority mail to Doc to test and see what the specs are before we go all in.

 

[oofnik]

Sweet.
Are these the same cells Ian tested over at ZEVA? If so, they look pretty good. A source for them would really be great. However I think for e-bike applications the 26650 size would be a better choice, don't you?

On a different note, I would really like to see these cells from Voltphreaks tested. They are offering a crazy good deal on a quantity of 50+ cells.

 

[dimitrib90]

Here is a picture of the cells. I dont think that these cells can discharge 10C but you never know.

 

[oofnik]

You can't tell a cell's discharge rate by looking at it, you know.
Wait for the tests and let the cells speak for themselves.

 

[dimitrib90]

Yea I posted the pick to show people the type of cell that it is. I got these from cammy-cc and my 24V 40ah is made out of these. Cammy told me that this battery could do 3C but the BMS cant do more than 1C. I was wondering since the wires are already there and soldered to the batteries, could I just get a different BMS so that I will to able to discharge to the full capacity?

 

[oofnik]

I suppose you could do that.
I wonder why they would package an underpowered BMS with cells that could do more... :|

I also wonder if those are genuine Valence cells there. I wouldn't have any reason to doubt, but considering China's market specialty...

 

[Toronto_ebiker]

I suppose you could do that.
I wonder why they would package an underpowered BMS with cells that could do more... :|

I also wonder if those are genuine Valence cells there. I wouldn't have any reason to doubt, but considering China's market specialty...

Only one way to find out... test them

 

[MitchJi]

Hi,

I also wonder if those are genuine Valence cells there. I wouldn't have any reason to doubt, but considering China's market specialty...

Only one way to find out... test them

Sending a few to Valence might be a better way to find out if they are genuine.

Before you move ahead on testing and verification of the 18650 cells you should see if you can get a similar price on the 26650 cells.

 

[dimitrib90]

Hi,

I also wonder if those are genuine Valence cells there. I wouldn't have any reason to doubt, but considering China's market specialty...

Only one way to find out... test them

Sending a few to Valence might be a better way to find out if they are genuine.

Before you move ahead on testing and verification of the 18650 cells you should see if you can get a similar price on the 26650 cells.

Personally I dont care if they are genuine, I just care if they test as well as Valence's batteries.

 

[MitchJi]

Hi,

Personally I don't care if they are genuine I just care if they test as well as Valence's batteries.

Personally I don't care if they are genuine either. I just want to be sure that all the cells I purchase are as good as Valence cells.

How throughly do you plan to test the cells? Number of discharge cycles and calendar life are big issues.

If they are not genuine the quality control might not be as good. Just because a few cells test out OK doesn't mean every cell in every batch will be the same. The following was posted on the EVDL after a large group purchase of cells. Before that purchase they did very through testing of individual cells:

A while back a group of EVDL members arranged a group buy from TS. TS had
a bunch of batteries that didn't pass their crappy QC so they decided to
offload them on the Stupid Americans. They KNEW they were bad cells and
they sold them anyway.

These days folks that are smart go to the factory in China and test the
batteries before buying them. They end up rejecting many of them that
pass Thundersky's QC.

If TS is willing to sell known defective batteries to us, what do you
think they are going to do with ones that pass their "QC" but aren't
purchased by the above buyers?

Even folks who buy LOTs of batteries from TS, have had batteries that
looked good initially but failed within the first year. Internal
corrosion caused by poor quality control during assembly.

If you're comfortable taking that kind of crap shoot with that much money,
knock yourself out.

Something similar is probably much more likely with counterfeit cells as opposed to a direct purchase from a company selling their own product.

The odds of getting any kind of warranty coverage if you get a bad batch of fake counterfeit cells is probably close to zero.

 

[dimitrib90]

Hi,

Personally I don't care if they are genuine I just care if they test as well as Valence's batteries.

Personally I don't care if they are genuine either. I just want to be sure that all the cells I purchase are as good as Valence cells.

How throughly do you plan to test the cells? Number of discharge cycles and calendar life are big issues.

If they are not genuine the quality control might not be as good. Just because a few cells test out OK doesn't mean every cell in every batch will be the same. The following was posted on the EVDL after a large group purchase of cells. Before that purchase they did very through testing of individual cells:

A while back a group of EVDL members arranged a group buy from TS. TS had
a bunch of batteries that didn't pass their crappy QC so they decided to
offload them on the Stupid Americans. They KNEW they were bad cells and
they sold them anyway.

These days folks that are smart go to the factory in China and test the
batteries before buying them. They end up rejecting many of them that
pass Thundersky's QC.

If TS is willing to sell known defective batteries to us, what do you
think they are going to do with ones that pass their "QC" but aren't
purchased by the above buyers?

Even folks who buy LOTs of batteries from TS, have had batteries that
looked good initially but failed within the first year. Internal
corrosion caused by poor quality control during assembly.

If you're comfortable taking that kind of crap shoot with that much money,
knock yourself out.

Something similar is probably much more likely with counterfeit cells as opposed to a direct purchase from a company selling their own product.

The odds of getting any kind of warranty coverage if you get a bad batch of fake counterfeit cells is probably close to zero.

Well first I was going to give the individual cells to Doc to see what their specs are. For my battery, Im going to get a better BMS so that I can actually find out what these cells can really do. The main problem is that my 24V 40ah battery pack doesn't have much use if it cant discharge over 1C. I am going to stick this pack on my new bicycle with an RC motor, controller, and servotester. Once I finish this project, I will be discharging the battery everyday for a couple of years and Ill let you know how it goes. (I probably wont use them for that long but you never know.)

 

[jumpjack]

Official datasheets now online:
http://www.valence.com/sites/default/files/18650_cell_datasheet_may_2013.pdf
http://www.valence.com/sites/default/files/26650_datasheet_april_2013.pdf

25,6V module:
http://www.valence.com/sites/default/files/power_cell_module_jun_2013.pdf

Valence states it's now selling single cells.
Does anybody know where and at how much?