1) Charged starting from 3.4V, so not fully discharged, the image above does not show the full capacity.
2) Charging capacity is always different from discharge capacity.
3) My discharging function on my charger doesn’t work, waiting for a (better) replacement charger which is currently backordered, so can’t do a proper capacity test atm.
4) Just ordered a controlled load to have another device to test with, this one here reviewed by HKJ: Test/Review of Electronic load 60W, because who knows how long the backordered charger will take to arrive.
5) Engineering samples have undergone thermal and/or load cycling, performance may not represent that of a brand new cell extracted from a model 3 or powerwall 2.
Length: 70mm +0.05/-0.05 (The metal body only is 70 +0/-.05 but the plastic ring can stick up above by 0.05)
Diameter: 21mm +0/-0.06
Weight: 69g +0.5/-0.5
Yeah, basically
Unfortunately just based on these recharges from 3.4v it seems that the best case scenario is close to 5000mAh, not more.
This puts the Wh/kg and Wh/L up with the best 18650 cells, but not far above, just as I had predicted based on the model 3’s cell count and battery capacity.
Will still be interesting to see what the actual mAh of the cell are
The real model name of this cell is: Sanyo NCR21700A which has a nominal capacity of 5000mAh and a continuous discharge rate of 3C, therefore 15 Amperes in continuous discharge. Tesla does not manufacture any cells themselves, in the Tesla GigaFactory equipment and personal from Sanyo work to produce EV cells under contract with TESLA, so Tesla do not manufacture themselves, it’s a kind of outsourcing home. This cell has been rewrapped for some time by Vapcell, I give you the link below. The only major defect of this cell is its positive pole which is recessed posing some contact problems in the 21700 compatible device.
There is no sanyo NCR21700A.
There is a sanyo NCR20700A which is 4000mAh or a Panasonic NCR21700A which is 5000mAh.
Maybe you’re getting confused because panasonic owns sanyo.
Everyone already knows panasonic is making tesla’s batteries btw.
Also, just as with the “3500mAh 18650” cells the real world performance is always less, you will not get 5000mAh at 3C discharge, MAYBE at 0.2C.
The real world capacity will be somewhere between 4500 and 5000.
It is Panasonic that produces the NCR21700A and not SANYO, but there you quibble because they are the same two brands, we can say that it even merge, I knew perfectly that SANYO belongs to Panasonic, except that Sanyo remains independent on many of its production and model, otherwise there would be no Sanyo NCR20700A, Sanyo NCR20700B and Sanyo NC2070C, and they are well stamped Sanyo and not Panasonic. For the NCR21700A, wholesalers sites that provide Vapcell with this clearly denominates “Panasonic NCR21700A” but hey have you listened I do not know what I’m talking about, while I was wrong that’s all, the mistake is human , no?
For the history of the 3C: I never said that the NCR21700A gave 5000mAh with a continuous discharge at 15 amps, I just gave his technical specs official ie: nominal capacity of 5000mAh and continuous discharge current maximum of 15 amps is 3 times its load so it gives 3C in C-Rate calculation, when I write something at least read it correctly, thank you.
PS: I just learned the only cell that has a common production between Panasonic and SANYO is the NCR18650GA, and that’s all, if in the other models of these two brands, you see two different brand names for the same model is simply a mistake.
The average internal resistance of the 4 NCR21700A cells I own is about 12 milliOhms in ACIR-1kHz (Tested with YR1035 Internal Resistance Tester). How much did you get on your measure, just out of curiosity?
This is perfectly normal, Vapcell applies retail prices to individuals / public in their store, when Vapcell sells to NKON, they make them wholesale prices and NKON purchase large volumes by contract of regular supply, therefore NKON can afford to sell Vapcell batteries cheaper than Vapcell themselves in their Store, there is nothing illogical on the contrary, it must be attractive to the customer, right?
So I did a discharge test at 2A using my new hobby charger and got 4630mAh down to 3V. unfortunately it doesn’t let me discharge any lower than that
Consistent with the results form this test:
Still haven’t received the battery discharger I ordered from banggood, but when that gets here I will do more tests.
Promising results, higher Wh/L and Wh/kg than any 18650.
I’m curious to see how it compares to the LG M50 and samsung 50E.
In this case, you will see the Sanyo NCR21700A is the most efficient (discharge / capacity) in this range, then come the Sony (finally Murata, lol I still have trouble with this brand name) US21700VC7 which is very close, then the Samsung 50E much less powerful than the two previous ones (at the same time the two first ones have maximum continuous discharge of 15 Amperes, the Samsung 50E him has 9.8 amps officially) and lastly comes the LG M50 but which does not fare too badly for a cell with a maximum discharge of 7.35A (1.5Cx4.9Ah). In short, you’ll see …
Hi Enderman and HydraXX -
I ordered one of the Chinese load calculators (eBay) and it must have been a seconds - because everything was off on it. The current was off, and wattage was off, and even the time clock was off. The only thing accurate with it was the voltage. They had not bothered to calibrate it and I could not find how. It came with no instructions and could not take the 150W advertised load - and pooped out (error) at about 90W. It was constant current. But without the Wh meter working, it was useless. So beware.
I have read elsewhere that the Tesla 21700 is rumoured to be at 5.75 Ah. But your report is the first I have seen with a real cell, and not just guestimates. I would be rather surprised if it is at 5.75 Ah. On the other hand pls. note that your charger/discharger may not be so accurate. I have one that looks similar to yours and it consistently underreports the discharge by about 10%.
I am also in Vancouver - so may I ask what kind of project are you working on? I am trying to electrify a small airplane, and find today’s L-ion to be somewhat short of desire. If the Tesla cell does not increase capacity by 10 or 20%, we are truly hooped. The NCR18650B came out IIRC in 2013. And there has been no off-the-shelf improvement for the gravimetric energy density? So depressing.
I bought this exact discharger which got a good review from one of the battery and electronics experts on this forum
It’s 5Ah, this test is accurate:
They are the exact same cells I have.
I still haven’t received my discharger yet but I have a new hobby charger which discharged the cells down to 3v and got 4600mAh at 2A which is in line with the test linked above, so I’m confident their numbers are correct.
I build mainly flashlights and remote control vehicles.
The improvement is at most a few percent, not anywhere near 10-20 unfortunately.
Hopefully in the future they can get closer to the theoretical 300wh/kg
18+ battery content warning. Still haven’t made it through this whole video but it is interesting. Especially, about why he thinks Tesla is interested in Maxwell Technologies. Around 12 minutes he starts talking about Maxwell’s dry coating electrode process that would eliminate a production speed limiting drying oven. The process would also replace a particularly nasty solvent with something more easily handled. All of which decreases manufacturing cost. While electric cars won’t entirely replace gasoline vehicles for various reasons, there is a tipping point where the decreasing cost of batteries makes them comparable in cost to a gasoline car. At which time paying around a 1/3 of the cost per mile to drive becomes a very attractive option. He is also developing what he calls “selfish solar” using entire Tesla battery packs. Spoiler alert. It is still cheaper to buy electricity from the big electrical companies. But, there are some applications out there where it starts to make cents.
“While electric cars won’t entirely replace gasoline vehicles for various reasons, there is a tipping point where the decreasing cost of batteries makes them comparable in cost to a gasoline car. At which time paying around a 1/3 of the cost per mile to drive becomes a very attractive option.”
And then this will be when the next “tipping point” is your Local, State and finally Federal Gov’t’s will issue a “Road use Tax” to make up the lost fuel tax for road upkeep and construction.
Already happening in some states.
Say what you want about Gov’t. They may not be good at using your tax money efficiently but they are Very Good at collecting it
