Last year, Samsung had a small outflow of Samsung 50s. This year, it will be more, but it is still very limited
This is a 21700 5000mAh 25A continuous discharge battery, which has both capacity and power
I dont think these batteries will make it past the dewalt/makita/milwaukee and then the scooter companies and get to get to flashlight users.
Instead of introducing a new battery that we wont be able to buy, you should tell us how Samsung is increasing production so we can actually find some at decent prices.
Thanks, most venders wonât tell you whatâs under the wrapper.
I always wondered - are these outflow cells grade A? For these major manufacturers about 2% of production cells cannot meet the QC and where do these cells go?
Molicel has authorized dealers so grade A can be guaranteed if you buy from authorized dealers. However Samsung, Murata, LG and Sanyo/Panasonic do not have authorized dealers, can resellersâ description of grade A be really trusted? Even they are on Moochâs trusted list? For re-wrapped cells, what grade of cells were used?
Also for Chinese brand cells about 4% of production cells cannot meet the QC.
And official CDR rating for Samsung 50S should be 20A (without temperature cut) and 35A (with 80â temperature cut). Donât know why Vapcell claims 25A CDR
This is the 25A CDR marked in 50s specification
It was originally thought to be 20A
The specification shall prevail
This is Grade A. the original packing is unopened
One batch, same date, batch production
Vapcell deserves recognition that they were able to stock samples of this particular cell. The cells I received last week are probably factory samples as they carry scratches on the tube? Other branded cells from Vapcell always came in perfect mechanical conditions. I tested three samples and their initial parameters correspond to the manufacturer`s specifications of this particular type, also parameter consistency is good.
Nominal (0.2C) capacity / IEC DCIR at 50% SoC measured at 25 °C in temperature chamber
5.0371 Ah / 14.1008 mOhm
5.0266 Ah / 13.9924 mOhm
5.0208 Ah / 13.9593 mOhm
For comparison I am adding the values of a new Samsung 40T3 model:
4.0944 Ah / 14.6298 mOhm
However, according to my measurements, I would rather label those 50S samples as 20A CDR, because at 25A CDR (5C) I measured the temperature of 74 °C at the end of the discharge in a temperature chamber with forced air circulation with temperature of 25 °C. This is significantly more than âestablishedâ 5C rated cells. For example 40T3 ends 5C discharge with 59 °C or 30Q6 with 61 °C under the same conditions.
So, when can we get these cells? Anyone find them for sale yet? I want them on my eBike.
Vapcell sells them as the âT50â and they are $24 a cell right now. The 50S is not good for longevity. The 50S will match a 40T3 in capacity after ~300 charge cycles and is basically toast at that point. The 40T3 will last 1,000+ cycles. See: Cycle life tests of High Power density cylindrical cells | Endless Sphere
The 50S is made for applications with a BMS and careful cell management (like power tools). They donât like being overcharged to 4.2v all the time and prefer a nice soft cutoff voltage, something we donât always get in flashlights. 9f you use them.in single cell applications the longevity is not good. Plus theyâre super expensive. Your better off getting P42As or even 50Gs (or 40T3).
Damn, I didnât know charging to 4.2V was considered overcharging.
Interesting. Though, that was 100% DoD and 5C discharge, on bikes we commonly only charge to 90% and average discharge is more like 1C or less, with 2-3C peaks for a few seconds.
Yes, that was a âhard useâ test. But look at the OP. That datasheet says >60% at 250 cycles. Many other cells are >80% at 500 cycles.
Iâm willing to bet Samsung took their standard NCA chemistry, and just slapped an even higher percentage of silicon in the anode without really taking care of silicon anode expansion at high charging voltages.
That way, theyâd be able to offer high energy density(270Wh/kg) and high power density.
Of course, if you charge at high voltages(>4.10-4.15V), that does mean anode silicon expansion is likely pretty severe.
1 Thank
Nkon few weeks ago listed them in their store Samsung INR21700-50S 5000mAh - 35A - 21700 & 20700 - Li-ion - Rechargeable batteries | NKON I was able to order samples from there before they went out of stock. If something doesnât go wrong, I will soon add sample to the ~90% DoD 1C test. Also thinking about re-testing 50S at lower discharge rate like 4C to limit the max temperature up to 60°C.
50S samples coming from Vapcell show significant cycle life problems even at low C-rate at 100% DoD. So yes the high DoD seems to be the major limiting factor for 50S. Will see if there will be any significant change in the samples coming from Nkon.
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Interesting and more on individual. I donât really care how many cycles my cell can do. Do we actually count them???
I discard them every 2 years regardless of any factor.
At any time, since I have gotten charger with capacity test(4.2V down to 2.8V) and ~IR reading, for eg, any 30Q within 2 years that has a capacity of less than 2900mah, IR over 100mohm, I will discard them.
Having said that, I have a few pieces of T50 (50S under the wrapper) that I paid half the current price. Why notâŚ
For the price now, no way for me, Iâd rather go for P42A.
the extra .1v cuts useful life span in halfâŚ
50S is in stock at 18650 Battery Store.