Today I finally recieved my 40T5’s from Nkon! The 5 under the ‘S’ from Samsung indeed indicates that it’s a new version, since the 40T3 has a ‘3’ on that spot and the original 40T (the “version 1”) didn’t had a number in that spot.
On the photo below I compared it with the first version of the 40T, since I don’t have a 40T3. The original 40T is on top, the 40T5 is below it.
I haven’t got the equipment to do really in dept and accurate battery tests, but I will do a capacity test and IR tests on my Opus BT-C3100. To limit the possible variations between the different slots on the charger, I will test them all in the same slot, so that I will get the best results for the batteries relatively to each other. Doing it this way it does take a bit longer, so it will take several days before I have the results.
All the four 40T5 batteries where at 3,453 Volts (measured with DMM) when I recieved them today, so maybe a tiny bit on the low side, but nothing to really worry about.
It wasn’t a normal datasheet with (continuous) discharge rates, number of charge cycles, etc., but more a document with comparisons between the 40T3 and 40T5 in terms of the new/different construction of the 40T5.
Given that the document is labeled ‘Confidential’ all over by Samsung and explicitly states that only they are allowed to distribute it, I don’t feel comfortable to share it publicly, because I don’t want to get Nkon (or myself) in trouble.
This ‘confidential, we are hiding everything’ approach is more and more annoying. If they don’t say what the differences are they should not sell these products at all, imho.
Be careful with what you say, remember that sourcing cells from Murata, Samsung, and LG was getting harder every year, because they only want to sell to OEMs and try to keep them from consumer hands.
It’s also probably why the M58T and other “next gen” high capacity cells are so scarce, with unobtanium-level info.
If you check each manufacturers website, it quickly becomes clear they’re purposely avoiding b2c sales, with pretty much the minimum information possible, needing to contact for anything more detailed.
Samsung SDI only lists old outdated cells on publicly accessible information for example.
Murata’s public datasheets are all as simple as possible
LG Energy basically has no information available other than “we make cylindrical li-ion cells”
Even the chinese manufacturers are pretty quiet with their information and datasheets, but at least there’s other ways to obtain datasheets from them.
Like with their LEDs. Seems to be a general thing with them…
Probably because they want to avoid liability in the event of accidents or mishandling of the cells. (The printing of ‘never carry or handle’ is also a clear sign for this.) Avoiding distribution to B2C seems to be the quickest and cheapest way.
Not really, the LEDs are way tougher, probably because they’re sold and used inside China, whereas the batteries are commonly also used elsewhere.
The batteries are easy in comparison, with BAK having datasheets available for everyone, though Lishen doesn’t provide datasheets. I tried to ask myself, and they wanted way too much information.
A lot of the manufacturers are leaving their cells at 30% SOC after initial testing so their voltage will be lower than we’ve seen over the years. This reduces the amount of energy available to support a fire in case the cells are shorted/damaged during shipping.
I have done a capacity test on my four 40T5 cells. I tried to eliminate as much variables as I could, to get the most accurate results, within my limited means.
The discharge capacity test was done on an Opus BT-C3100 and all cells were tested in the same slot. The discharge current was 0,7A/700mA.
Obviously not sure how accurate the capacity results really are, but it should at least give an idea how they performed, relative to each other.
Tested capacity:
Cell 1: 4194 mAh
Cell 2: 4198 mAh
Cell 3: 4181 mAh
Cell 4: 4182 mAh
Given the fact that all 4 cells tested so close to 4200 mAh, so almost 5% above rated/typical capacity, I suspect that my Opus measured a bit on the high side.
I will also do some IR testing in the next few days, to see how well these cells measure up/match each other.
Thank you. Seems just like a small change in production without changing the performance or design. The 40T3 cells should also be just fine for our purposes.
Nothing really worth discussing about tbh. Only advantage is that 40T5 are guaranteed to be newer as 40T3.
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