Samsung INR21700-48G | Page 2 | Endless Sphere DIY EV Forum

Hillhater

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• Jan 14,

• #26

Have you seen other tests on these cells ?
Here is one such, on this forum.. https://endless-sphere.com/forums/viewtopic.php?f=14&t=
It fairly clear from those tests that the full mAh iis available , but there is very little between 4.2-4.1 volts (350mAh ?). And less in the 2.9 - 2.5 volt range (200mAh)
And here the test only ran to 2.8 v cut off, but still discharged over mAh
http://lygte-info.dk/review/batteries/Samsung%20INR-48G%mAh%20(Gray)%20UK.html
So , run your 4.2-2.5 volt discharge test, then compare results and test methods.

ElectricGod

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• Jan 18,

• #27

Life has been busy!

I have done discharge tests on several sets of cells now down to 2.5 volts from about 4.1+ volts and I'm consistently seeing mah or less.

I have tried load testing at about 11 amps, 6 amps and a few lower current draw amounts. mah is about all I ever see. I'm recording my results as I get them and will post that later. I'm not overly excited about these cells! Charging from around 2.5 volts to full typically gets me mah or less.

ElectricGod

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• Feb 7,

• #28

Well I am done testing INR-48G cells!

The INR-48G is disappointing. The best I have gotten is mah and typical has been mah. I've never gotten mah and IR is pretty high. I seriously doubt I will buy more of this cell. I've now charged and discharged every one of the 40 cells I have on my SkyRC charger and a Chargery 12S balance charger twice each per cell and get similar results. I've also used a watt meter and my halogen bulb load...same thing. My test results are 100% less than acceptable. Samsung is over rating these cells. That or I got 40 sub par cells!

IMHO...buy something else...the 48G is at best a lack luster cell. MEH!!!

Hillhater

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• Feb 7,

• #29

Did you compare your test method and equipment with others who have achieved satisfactory results ?
Have you checked /recalibrated your measuring equipment ?
Did you run control tests on other known capacity cells ?
Its not likely that other reputable tests have falsely achieved spec results, and equally unlikely you have received 40 bad cells. ?
So you have to suspect an error in your equipment or test proceedure.

TheBeastie

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• Feb 9,

• #30

That is a pretty good cell, but after looking around online it seems pretty expensive for the pure Ah/$.
If you didn't look at it or know it was a cell you wouldn't be so interested.

I was thinking the cell is kind of similar to my current battery pack of Samsung 29E cells which are also quite a low C-rate but were excellent value at the time I bought them, when I first started testing a battery pack out with them I found 4P was not acceptable for me on a 500W Bafang ebike. So I bought more cells and made a 7P pack, this has worked out well as I only charge at best once a week. Being doing a lot of lazy summer rides this summer and have managed to get 100KM range out of the pack due to going slow.

Looks like this INR-48G is kind of the next generation of such a pack but it needs to be cheaper in terms of pure Ah/$.

youyoung

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• Feb 15,

• #31

@ElectricGod : your conclusion reach mine ! These cells are overpriced and useless.

I think they are 35E chemistry fitted in a larger case : when you normalize numbers and curves proportional to the cells mass, you get the same (=poor) cycle life and slightly more saggy discharge curve.

When you think about it, the form factor is better for small applications and high discharge rates : more cooling surface and less distance between battery poles and internal windings. And the ability to increment your packs in smaller steps for better fit.

Pajda

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• Feb 17,

• #32

Finally I got one tester channel free and start with cycle life test. It will take at least one month to get some initial results. But I have no problem with nominal capacity. On my calibrated 4-wire tester I got this results:

Nominal capacity test*: capacity: 4.795 mAh, energy: 17.400 Wh
My cycle life test 100%DoD**: capacity: 4.766 mAh, energy: 16.590 Wh

*0.3C charge( mA) to 4.2V @ 100mAh cut-off -- 10min rest time -- 0.2C discharge (960 mA) to 2.5V
**0.5C charge( mA) to 4.2V @ 100mAh cut-off -- 10min rest time -- 1C discharge ( mA) to 2.5V

coinmaster

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• May 2,

• #33

So did we conclude these cells are a rip-off? Even if they come out at just ma that is still better than anything else on the market by weight is it not?

Pajda

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• May 3,

• #34

This Samsung format cell have very problematic cycle life when compared with most of cells. There are many cells in format on the market which have better performance, better cycle life, better energy density and they are also significantly cheaper. So after my testing I do not find this cell interesting.

ElectricGod

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• Aug 30,

• #35

Pajda said: This Samsung format cell have very problematic cycle life when compared with most of cells. There are many cells in format on the market which have better performance, better cycle life, better energy density and they are also significantly cheaper. So after my testing I do not find this cell interesting.

I agree. I have 40 of them just sitting in a bag. Not the best purchase I've ever made. Oh well!

ElectricGod

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• Sep 28,

• #36

I recently got an Icharger DUO and an ISDT D2. I have not used these cells at all except in bench tests. They have been sitting in a box hovering around 3.5 volts for a long time. I am charging and discharging them on the and the D2. I was curious to see if I got significantly different results than before on my D100.

Ir is usually in the 35-50 mOhm range.
Capacity is typically mah.

I should make one note in my capacity testing. I'm discharging from 4.1 to 3.1 volts. I expect a little less capacity than I'd get if I went down to 2.5 volts. However, in all honesty, you would be stupid to bother with 2.5 volts in any real application.

I think it's time to find some more cells and do more testing. This early batch of INR-48BG cells were disappointing.

Pajda

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• Sep 29,

• #37

I have some new info about cycle life tests for 48G.

Under my first standardized test 0.5C-1C 100% DoD settings the results should be marked as "disaster / non usable" I have run this setting on another cell sample with similar result. But then I lower down the charging current to 0.3C (manufacturer recomended nominal charging current) and now running the setting 0.3C-1C 100% DoD. The results are now much better and I give the mark" usable", but still there are cells in and format with better cycle life even with higher energy density.

Under my second standardized test 0.5C-1C 50% DoD (from 100% to 50% SOC) this 48G perform very well and is fully comparable to the best and cells on the market.

Short conclusion: This cell is usable if you plan to use slow charging /regen. But there are much better cells with lower price on the market. LG INR M50 is better choice in all aspects including the price.

Comparing it at 20A and 30A to its high current 3Ah peers like the Sony VTC6 and the Samsung INR-30Q, the big advantage seems to be much cooler operational temperatures. I don’t think any of the cells can be safely used at over 18A-19A in continuous use. Looks like the INR can be safely used at 25A for continuous use. The e-cig guys will be loving this cell.

Read more

It can be used at safely at 35A as long as it have free air around it (A metal holder can be very close to free air) (It did not get too hot in my 40A test). That is the reason I call it the best high current cell I have seen.

I hate it, it means I have to do some extra work.

JOINSUN contains other products and information you need, so please check it out.

A new battery holder looks like this:

But I change the connecting wires and this means when it looks like this I have work to do:

Where in the world can I order these cells? I’ve been using the Sanyo B, but I really want to get my hands on those. Any info or links would be greatly appreciated.