Compoundbike
100 W
Has Anyone used those cells? Just saw those on NKON they're claiming to have 5570mAh at least with 12.5 ah continuous.
LG INR21700-M58T?
- Thread starter Compoundbike
- Start date
I googled a couple threads.. here's one that's relevant:
https://budgetlightforum.com/node/82096
Could not find a datasheet for them..
Seems to live up to a ~5700mah capacity according to people testing them, but i cannot find a datasheet on these.
Some people noticed that there were spot welds broken off them etc; my best guess is that they're a newer generation of cell made for a certain manufacturer and haven't really hit public availability yet.
They may be pulls from some device or car.. IE lightly used.
Supposedly these are ~275whr/kg cells it's quite exciting that such things even exist out in the wild. C rate is probably garbage ( ~1C
) but it'd be just the ticket for building a >2kw-hr pack with to tour with.. or build a solar storage battery with 
https://budgetlightforum.com/node/82096
Could not find a datasheet for them..
Seems to live up to a ~5700mah capacity according to people testing them, but i cannot find a datasheet on these.
Some people noticed that there were spot welds broken off them etc; my best guess is that they're a newer generation of cell made for a certain manufacturer and haven't really hit public availability yet.
They may be pulls from some device or car.. IE lightly used.
Supposedly these are ~275whr/kg cells it's quite exciting that such things even exist out in the wild. C rate is probably garbage ( ~1C
) but it'd be just the ticket for building a >2kw-hr pack with to tour with.. or build a solar storage battery with
Compoundbike
100 W
C-Rate looks like 2 times? it's also a expensive cell.
Probably good for long range if done right.
Probably good for long range if done right.
Compoundbike
100 W
My mistake I meaned discharge Rate. 12.5 Ah: 5.6= 2..
"These batteries are from a canceled car project" I guess those cells won't be easily released again.
"These batteries are from a canceled car project" I guess those cells won't be easily released again.
Pajda
10 kW
The fact is that M58T is quite new cell, but it is likely that more >5000 mAh cells in the 21700 format will appear very soon. Close to the mass market is BAK N21700CD 5300 mAh cell. http://www.bakpower.com/yybk_rlx_en.php
Found this, supposedly it's a rewrapped LG
Vapcell F58 5800mah 21700
Saggy.. but if you want a high range pack... this would be it @ something like 285whrs/kg
Vapcell F58 5800mah 21700
Saggy.. but if you want a high range pack... this would be it @ something like 285whrs/kg
Chalo
100 TW
Not once you finish assembling a sack of lipsticks into a pack that can dependably bounce down the road at speed. The more cells you need, the more structure and packaging you need, the more you negate any Wh/kg advantage as you add points of failure.
Seems like a great cell for a dry herb vape or an EDC flashlight. It's about the right size for that job.
Pajda
10 kW
First of all for clarification, the cells supplied by Nkon are described on the body as M58 (without T) even though they are listed as M58T.
And secondly here is the cycle life data compared to the Vapcell F60. It can be seen that both models are suitable for practical use. Regarding the F60 results, it is fair to say that these are probably FEB cells, which have a prescribed discharge limit of 2.75 V, whereas I tortured them down to 2.5 V, hence the sudden death at 100% DoD.
And secondly here is the cycle life data compared to the Vapcell F60. It can be seen that both models are suitable for practical use. Regarding the F60 results, it is fair to say that these are probably FEB cells, which have a prescribed discharge limit of 2.75 V, whereas I tortured them down to 2.5 V, hence the sudden death at 100% DoD.
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Tomblarom
10 W
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There is some stock in italy: 100x Zellen LG2170-M58T Neu Original 5800 MAH | eBay
Pajda
10 kW
I was considering starting a new topic with the clickbait "Do LIB really not suffer from the memory effect?", but I find it disrespectful to the community. The idea is based on the observation of my LIB cycle-life data, where you maybe noticed that cycling at a constant SoC range, lower than 100% produces so-called waves in the data. As it happens, some cells seems do not suffer much from this phenomenon and others have it very visible, which is the case of the LG INR21700 M58 model.
What is considered a memory effect in this case? It is a gradual loss of usable cell capacity during cycling, which is not permanent and can be restored.
What causes it in a real application? Long-term cycling within limited SoC window.
How capacity can be restored? The cell needs to be charged to 100% SoC.
Let's take a look at the M58 cycling data. Here we see a standard cycling life test with 0.5C-chg and 1C-dchg settings with limited SoC window to 4.15V-3.00V (ca 90%) for 49 cycles. This setting is the same for all three samples in the graph. The difference is caused by the nominal capacity test, which is inserted every 50 cycles. For red (M58) and yellow (F60) samples the nominal capacity test cover 100% SoC which is 4.20V-2.50V, but for blue sample (M58) this nominal capacity test is limited to 4.15-3.00V (the same SoC as for cycling) where in the 200th cycle a full 100% SoC cycle 4.20V-2.50V is inserted to demonstrate this phenomenon.
Also, you may have noticed that the blue sample (M58) experiences little capacity recovery even when the nominal capacity test is inserted with the same 4.15-3.00 SoC. This is due to the fact that the nominal discharge rate 0.2C is here used to discharge instead of the test 1C rate. Thus, the cell discharges deeper (to lower OCV voltage) at 0.2C due to the effect of cell IR.
So the conclusion is that some cells like F60 sample does not suffer significantly from the memory effect, but with the M58 you can lose a significant amount of usable energy during the life cycle of the pack thanks to this phenomenon.
What is considered a memory effect in this case? It is a gradual loss of usable cell capacity during cycling, which is not permanent and can be restored.
What causes it in a real application? Long-term cycling within limited SoC window.
How capacity can be restored? The cell needs to be charged to 100% SoC.
Let's take a look at the M58 cycling data. Here we see a standard cycling life test with 0.5C-chg and 1C-dchg settings with limited SoC window to 4.15V-3.00V (ca 90%) for 49 cycles. This setting is the same for all three samples in the graph. The difference is caused by the nominal capacity test, which is inserted every 50 cycles. For red (M58) and yellow (F60) samples the nominal capacity test cover 100% SoC which is 4.20V-2.50V, but for blue sample (M58) this nominal capacity test is limited to 4.15-3.00V (the same SoC as for cycling) where in the 200th cycle a full 100% SoC cycle 4.20V-2.50V is inserted to demonstrate this phenomenon.
Also, you may have noticed that the blue sample (M58) experiences little capacity recovery even when the nominal capacity test is inserted with the same 4.15-3.00 SoC. This is due to the fact that the nominal discharge rate 0.2C is here used to discharge instead of the test 1C rate. Thus, the cell discharges deeper (to lower OCV voltage) at 0.2C due to the effect of cell IR.
So the conclusion is that some cells like F60 sample does not suffer significantly from the memory effect, but with the M58 you can lose a significant amount of usable energy during the life cycle of the pack thanks to this phenomenon.
Pajda
10 kW
Thanks to the support of ES community i got access to the samples of serial production M58T model. In few weeks i will start cycle life test. Let's see if there's a significant difference from the M58 sample.
