NCR18650G 3600 mAh 2C capable

Anyone here got their hands on these yet? The only samples I can get are rejects that have been spot welded.

If they are NCA I bet they are going in the next Tesla pack for the topline Model X and Model S AWD. Nice upgrade over the current 2900 mAh PD (actually 3300 mAh grade AA PD cells, we only get the rejects sent to China for power tools and LEVs)

Less sag than the 3400 mAh B version for sure
The keeppower 3600 is the panasonic cell with protection
They add protection because they are buying obviously used cells and recap them
http://lygte-info.dk/review/batteries2012/Common18650comparator.php
Looks similar to the samsung 29E IR wise
The fact the knee at the end is not sharp likely indicates NCA
Fingers crossed

There is no cell in the link of 3600 mAhr capacity. .??

There is under 18650 keeppower black

Note the curves only go down to 2.8V while the rating is based ona 2.5v cutoff

Like i I said the keeppower 3600 black is a USED panasonic ncr18650G cell with protection (to cover for the fact they are actually used cells with already welded tabs)

"http://lygte-info.dk/review/batteries2012/Keeppower%2018650%203600mAh%20(Black)%202014%20UK.html

The cell does the not have the tesla c shape vent design but they are all pilot run cells salvaged from the dumpster by the Chinese

They were only made available to OEMs a couple months ago in sample quantities


Tesla uses them at 10.5 amps peak
A little over the 2c max rating beacuse they have active cooling
They charge at 135kw (1.5c) because
1) active cooling
2) they taper the charge (you will really shorten the life of the cell charging at even 1c with no cooling and no taper)
3) supercharging does shorten the life significantly (they are relying on the fact most people dont do it everyday

flathill said:

They were only made available to OEMs a couple months ago in sample quantities


Tesla uses them at 10.5 amps peak
A little over the 2c max rating beacuse they have active cooling
They charge at 135kw (1.5c) because
1) active cooling
2) they taper the charge (you will really shorten the life of the cell charging at even 1c with no cooling and no taper)
3) supercharging does shorten the life significantly (they are relying on the fact most people dont do it everyday

Click to expand...

This is the first /only time i have heard anyone suggest Tesla is using anything bigger than a 3100/3200 mAhr cell
Even the now established 18650B , 3400mAhr, cell has not been thought by "insiders" to be in Teslas packs.
If true , it would put the 7104 cell, Model S pack up at 92+kWhr capacity, and i would think Tesla would be shouting that loud and proud, from the rooftop !
What make you so sure they are using them ? ..or do you just think they are testing them ?

PS:--from those test curves, anyone attempting to get more than 3Ahr repeatedly out of those cells would be mad !
After the 3Ahr / 3.3v point the curve is already in freefall and has no chance of making anywhere near 3600mAhr , even if pushed to sub 2v at 0.2 C !..its just going to shorten the cycle life rapidly.

What are you talking about?
The cell measured 3.4Ah and was not fully discharged
Rated capacity is down to 2.5V

"The cell used can be discharged down to 2.5 volt, in my test I only discharges to 2.8 volt, i.e. I do not measure the full capacity. But then, not all lights will be able to use the full capacity."

I dont know if Tesla has the G cells or something better

Current cell is 3.3 Ah
The same cell is available to us but only 2.9Ah
3.3Ah x 3.65V nominal x 7102 cells = 85.5 kWh current pack

The new pack for the model X should be at least 105 kWh
The rumor is 110 kWh

Note Tesla doesnt use the full pack and the reserve changes over time
So even though the cells are aging to the end user the range is declining much slower
With a new pack 0 miles might mean you still actually have 12kWh in reserve
8 years later 0 miles might mean you still have 8kWh in reserve
This is how they guarantee 70% of new range after 8 years to Mercedes
But that is assuming range charge and worst case useage pattern
Even their range charge is a military charge 4.15V

flathill said:

...Even their range charge is a military charge 4.15V

Click to expand...

Damn military copying me again. :lol: 4.15V is all I've ever used starting in 2008 with my first batteries rated for 4.2V charge cutoff.

flathill said:

What are you talking about?
The cell measured 3.4Ah and was not fully discharged
Rated capacity is down to 2.5V

Click to expand...

Look at the "1C" line.
At 3Ahr & 3.0 volts, it is dropping 0.1v for each 0.1Ahr and getting worse.
So its not even going to make 3.5Ahr at 2.5 volts !...lucky if its 3.4Ahr !
In reality the "1C" line is a pretty tame discharge test for an EV cell .
And there is practically no difference in the max discharge "energy" at 12.5 Whrs compared to he 3.4 Ahr "B" cell
BUT. we all know that pushing the discharge "over that cliff" ( beyond 3.0 Ahr on these) is not going to encourage long life ..or yield much useful power.

If they are going to rate these as a 2C cell, they should be capable of 3.6Ahr AT 2C discharge. !
...but none of the Battery suppliers would do that !

Yeah Samsung and Panasonic and many others all use 0.2C to measure/state the rated capacity and the minimum capacity is typically 1000 mAh less than rated (aka typical)

Again these keeppower cells are USED with additional resistance from the protection circuit

But they measured 3.4Ah at 0.2c down to 2.8V which is damn good. If continued Down to 2.5V at 0.2C they would have hit 3.5+Ah which is in spec without the protection circuit. The fact the protection circuit was in place makes it even more impressive. For most it is hard to get excited about a few percent gains but if we do it every year....long term

There is only going to be a big jump in capacity if someone is brave enough releases a solid state battery

Those who have tried before have been have been buried but now Applied Materials is on our side so we are going to win

The cell is ~2C max, 1C continous, the SAME as the most popular NCA battery on the market for ebikes, the Samsung 29E, which is only rated at 2850 mAh @ 0.2C down to 2.5V. Quite an improvement if you compare it this way!!!!! I could go ~26% farther if I dropped this G cell in place of my 29E's at the expense of 1 additional gram per cell and a tiny tiny bit more sag (not an issue as what is the point of having an ebike that doesn't last more than an hour besides racing). An practical ebike must last a minimum of 1 hour which means 1C average. If you run out of juice in less than an hour you need a bigger pack. It's that simple. Imagine if the Tesla ran out of juice after an hour of normal driving. No one would buy it.



AGAIN NOTE THE KEEPPOWER CELL HAS A PROTECTION CIRCUIT
THIS IS AT 5 AMPS:

note the G cells don't appear to have the C shaped vent like the Panasonic PD cells do so they might not be destined for Tesla Model X or they could be using a new pack design without bond wires. Bond wires work well as a fusible connector and can be automated by robots, but are very fragile and sensitive to vibration. This is why Telsa glues all its cells in place. The next gen pack will not have the cells glued in place.

Here are the actual Tesla Roadster cells showing the C vent. The newer cells in the Tesla Rav4 have a PD style triangular positive terminal, and the C shaped vent

Tesla holds the patent on the C shaped vent. The purpose is to break the bond wire Tesla uses to connect cells to the bus bar when it opens.

I think the NCR18650BE must be the Model S cell. Rated at 3200 they probably give the lowest impedance grade A cells to Tesla that are probably closer to 3300 mAh which would match the 85kwh pack given we now know for sure the total number of cells

Note it has the Tesla vent design on the negative terminal (the patent shows both a O shaped and C shaped version)

Also has the triangular postitive terminal as seen on the Tesla Rav4EV. That means the PD version only went in the Rav4

Now it all makes sense

http://i.imgur.com/QtJJIuy.jpg

Isn't the PD cell too recent to have been in the Rav 4 packs ?
If you saw the video of the Rav4 pack tear down by Jehu (now deleted ??) ... All those cells tested at 2600mAhr. .?

Yeah so much for tesla opening their patents although I feel it was proababy Mercedes that served the the take down notice on the jehu evwest video showing inside the tesla/ mercedes smart pack (used or old packs)

I dont know what cells are in the smart pack but they are likely the same as the rav4ev the pd (28-2900 mah new at 0.2c)

Remember a cell just sitting for a year will lose rough 5-15% the first year depending on storage temp due to calendar fade. Keep em cool and you might get even less than 5% but most are stored in warehouses with no a/c

Even if you do manage to get grade a cells from china most are lots from 2012 or 2013 that panasonic or samsung unloaded on the chinese grey market. I havent from any PD or BE or 29e cells with 2014 lots numbers at all. Most are early 2013

Episode 35 was totally deleted

"
Update: There has been a little snafu with the OEM and the vids will be down until further notice…we’ll update when/if they are back online"

3.13. Storage Temperature
1 year :
3 months :
1 month :
-20~25°C (1*)
-20~45°C (1*)
-20~60°C (1*)

Note (1): If the cell is kept as ex-factory status (50% of charge), The capacity recovery rate is more than 80%.

3 months at 45c at 50% state of charge and all they guArantee is 80% of initial capacity!!!!

on a samsung nca cell!

now you see why samsung must dump any old cells on the grey market. no oem will touch old cells with a 10 foot pole. they want this quarter fresh cells

lucky the calendar fade stabilizes at 75% on nca cells after a few years and and slowly fades to 70% on year 20 or so if not abused

ncm nmc continues to calendar fade in a linear downward fashion which is why it sucks even though it has higher power density