New Panasonic Cell ncr18650bd 3200mah

[parabellum]

Was reading this whole tread once again and did find this link http://www.fasttech.com/products/0/10001980/1686800-authentic-panasonic-ncr18650be-3-6-3-7v-3180mah but do not recall if someone ordere from this source and confirmed those cells as legit. Any info?
Sorry if it was somewhere.

 

[okashira]

Was reading this whole tread once again and did find this link http://www.fasttech.com/products/0/10001980/1686800-authentic-panasonic-ncr18650be-3-6-3-7v-3180mah but do not recall if someone ordere from this source and confirmed those cells as legit. Any info?
Sorry if it was somewhere.

Uh, the cells I JUST tested on the prior page were from fasttech.
Still waiting on the BD's

 

[parabellum]

Was reading this whole tread once again and did find this link http://www.fasttech.com/products/0/10001980/1686800-authentic-panasonic-ncr18650be-3-6-3-7v-3180mah but do not recall if someone ordere from this source and confirmed those cells as legit. Any info?
Sorry if it was somewhere.

Uh, the cells I JUST tested on the prior page were from fasttech.
Still waiting on the BD's

O, I got the impression those are PF, or is it reliable source overal?

 

[okashira]

They are fine for all brand name 18650's if you don't mind 2 months shipping time.

 

[parabellum]

They are fine for all brand name 18650's if you don't mind 2 months shipping time.

Thanks. That is the hidden Free Shipping price.

 

[okashira]

Just for fun, added a 1A run of an LG E1 18650.
Great energy capacity. Blue curve at the top.

Testing the three cells I got as I'm going to put three of these suckers into an LG G2 smartphone as a side project. Should be good for nearly 1 week battery life. Since I'll be replacing the stock battery, it won't be too terribly thick.
Bonus - my phone will soon serve as a 9600mah powerbank.
I compared it to HJK's test of an E1, and the data lined up so well the points completely obscured each other. Makes me feel good about this test setup as he uses a $1000+ 4-wire DC load and a $1000+ 4-wire power supply to charge.
I'm using an arduino shield DC load and a $6 ebay chinese CC/CV power supply to charge.

Does anyone know how to display images without just creating a link on the forum? I did it before by accident...

 

[parabellum]

Does anyone know how to display images without just creating a link on the forum? I did it before by accident...

I upload the image, then puch img on top and paste url of the image in between. Sometimes they are visible 2 times in the post, big one and small copy at the end.

 

[okashira]

Does anyone know how to display images without just creating a link on the forum? I did it before by accident...

I upload the image, then puch img on top and paste url of the image in between. Sometimes they are visible 2 times in the post, big one and small copy at the end.

perfect! thanks

 

[okashira]

I completed a comparison between the Rank D and Rank B cell...

The B rank cell was putting out about 15-20mv more voltage at 1A and 3A. But this effect was less at 10A.
The D rank cell was about 1.5% lower capacity in each test to a 2.8V cut.

This is only a single B and a single D cell, so I don't know if this answers any of our questions. It could be that the B cells are just more consistent then the D cells, and a more statistically significant # of samples would need to be tested to confirm this. I am not going to unless someone wants to donate me cells.... :-D And until I design an automated charger/dis-charger setup.

Note on the 10A discharge of the B cell, I accidentally stopped the load for 8 seconds around 2.98V. Note the increased voltage for a brief period after the load was resumed.
This is because the chemical reactions and mechanical effects that occur within the cell continue to proceed even when the load is removed. The result is an increase in voltage during that time.
When modelling battery performance, this is typically done by modeling a capacitor in parallel with a voltage source where V = ƒ(T, SOC); and two resistors... one in series with the cap and voltage source, and one in series with just the voltage source. A temperature dependent resistor in series with the cap and voltage source too as this recovery occurs faster at high temps.

This is "free energy," what I mean is... a cell that is run under a pulse load will put out more energy then a cell with a continuous load. This appears quite pronounced for these Panasonic NCA cells, and is even more pronounced at lower temperatures (<75°F)

 

[riba2233]

Nice

When's the BD coming?

 

[okashira]

More then one week... they shipped Nov 27, but they're still on the boat

 

[tumich]

Panasonic's are the best cells on our planet.
I have NCR18650PF 2900mah and by discharge 10A they have 2750mah~

 

[parabellum]

okashira.
Nice graph!
Do you have or can figure out the resting voltage on 50% DOD?

 

[okashira]

Yes..
Actually I already ran that one.

This is another useful feature of these cells.... voltage is very linear with capacity making estimates of remaining capacity easy.
Approx 3.73V resting voltage (after 1 hour) for 50% SOC.

This was run on my "beat up" cell, but it should be the same for a newer cell.

 

[parabellum]

Thanks! Nice info.

 

[okashira]

I found a NCR18650BD discharge graph from Panasonic... They did 4A 6A 8A

I overlayed it with my test of a BE

At first, the 6A trace is even with the BE at 5A. this means the IR is 5/6 that of the BE. or 18% less DCIR, which is actually pretty significant, but not earthshaking.
The BE almost catches up by 2Ah, but this could be because the BE is warmer at this point.

Linear interpolating the temperature at 2.5V, the BD at 5A would be 45.5°C
I measured 45.7°C on the BE. But I just used some masking tape and a cheap thermocouple. So maybe 47°C.

but it looks like they started at 80°F, much warmer then me. That will help DCIR.
I'll be sure to test BD and BE back to back at same temperature.

 

[savaoaknyc]

Just for fun, added a 1A run of an LG E1 18650.
Great energy capacity. Blue curve at the top.

Testing the three cells I got as I'm going to put three of these suckers into an LG G2 smartphone as a side project. Should be good for nearly 1 week battery life. Since I'll be replacing the stock battery, it won't be too terribly thick.
Bonus - my phone will soon serve as a 9600mah powerbank.
I compared it to HJK's test of an E1, and the data lined up so well the points completely obscured each other. Makes me feel good about this test setup as he uses a $1000+ 4-wire DC load and a $1000+ 4-wire power supply to charge.
I'm using an arduino shield DC load and a $6 ebay chinese CC/CV power supply to charge.

Does anyone know how to display images without just creating a link on the forum? I did it before by accident...

Okashira nice tests.Soon i will be able too to do some tests with batteries and will post some results.We need a database with bench results like dampfakkus.de and http://lygte-info.dk/, but for ebike batteries with some lifecycle results as well.About your phone mod, pls post here some photos iam getting lg g3 this week and would like to see how this looks like.
Greets Sava

 

[Drokz]

Ohhhh NICE !!!! here are test results

 

[okashira]

The BD's are still on the boat... :-/
If anyone has some BD's... send them my way and I can test them and send them back.
If anyone has any battery they'd like tested, not just an 18650, I can do up to 20A discharge with this setup... just PM me. It's a 4-wire setup now and accurate to about +/- 0.0015V and +/- ~0.002A. I can setup the load to do anything, constant V, current, resistance, varying load, pauses to determine resting voltage, etc.

 

[okashira]

I wanted to test the old PF that I had abused earlier with a few shorts and a loaded discharge to 0.9V.

This test started at about 72°F.

At about 3.55V, I used a heat gun and heated the cell to about 95°F surface temp to see how much it affected DCIR.
The result was it lowered effective DCIR by about 35% at that point compared to resting voltage...!!!

The black trace is the same cell a few cycles back. I've since been using it to power another device for a few cycles. It seems to be holding up..

 

[okashira]

This is probably the last test to share before I get my BD's.

I wanted to compare the PF to the BE directly.
I took the BE I tested for Riba at 5A and did a 3A and two 10A, because I forgot to data-log on the first 10A run.

Lined up the data with my old PF and the more recent Rank B and Rank D PF data.

Basically, the BE performs like a PF, with 9-10% more capacity. Not bad at all.

But the BE got VERY toasty in the 10a draw. Got to 73°C by 2.85V. Was at 54°C half way through (1.5Ah)

2nd chart, zoomed in, you can see the DCIR is on the lower end of the PF's data, but that's still pretty good.

Given the temp, I wouldn't rate the cell for 10A discharge... But even dropping it down to 9A would probably get the temp to a reasonable level on a CONTINUOUS discharge.
15A burst should be fine for this cell as well. (20-30 seconds)

9A continuous is still plenty for any useful e-bike application I can think of. Remember, the 10A test only took 20 minutes. Who wants an e-bike with a 20 min battery life?

 

[cwah]

Where did you buy the be you tested?

 

[riba2233]

That's not to bad, Samsung 25R is rated 20A continuous, and at 20A it gets to 93°C, and at 10A it gets to 60°C.

 

[okashira]

That's not to bad, Samsung 25R is rated 20A continuous, and at 20A it gets to 93°C, and at 10A it gets to 60°C.

Is that to 2.5 or 2.0 V?

If I ran the BE to 2.5, it would have hit 80°C easy. 73°C at 2.85V.

At 3.0V it was 69°C. I guess you could do 10A cont. if you had temperature monitoring and cut at 3V or 65°C.
I believe they are rated to 70°C during operation.

This was with a taped on thermocouple and NO airflow. Maybe I should run one with a small fan to give some small airflow.

Where did you buy the be you tested?

fasttech

 

[riba2233]

That test was up to 2.5 V.

Yes, with some cooling system it wouldn't be problem at all, but still I wouldn't use them at 10A continuous because of the voltage drop. But for peaks, even 15 or 20 A is ok.