LG INR21700-M58T (5570 mAh)

Finally cell which can beat a mythical 800 Wh/l in cylidrical format?

I found this cell on Nkon store https://eu.nkon.nl/rechargeable/li-ion/21700-20700-size/lg-inr21700-m58t-5570mah-12-5a-clear.html only other source which listed this cell is EVVA 24V 36V 48V 72V LEV Battery Pack with A Grade LG INR21700M58T 5570mAh 12.5A Cell New Products EVVA-High End Lithium ion Battery Expert

Ordered samples from Nkon, I will start cycle life and other tests as soon as it arrives.

Im looking forward to your results. Hopefully voltage wont sag too much while under moderate loads. I suspect cycle life will be considerably shorter than most name brand lower capacity cells.

Wait wait wait.

At rated capacity, this is 280Wh/kg, and at minimum capacity, it is 270Wh/kg.

I’ve seen semi-custom form factors reach 300Wh/kg without taking into account lower packaging efficiency(which is functionally the highest with cylindrical cells), so this is impressive.

I wonder what is different about it at the chemistry level.

Some photos of M58T samples from Nkon. It can be seen that cells were removed from modules, but the welds are nicely cleaned. An interesting feature is the use of a one-side busbar connection in that app, I guess laser was used for welding. The dark circle in the middle of the positive terminal is probably caused by the laser as some surface treatment.

I hope to have first test results today.

Can you check the actual dimensions and post them here? Diameter, length, etc. Because according to the information from NKON and EVVA, it looks like this cell is a bit larger than the usual standard and I’m wondering if it will fit in some of my light where it was a tight fit.

EVVA states 21.80x71.0mm and NKON 21.3x71.0mm.

Look at the end of Nkon’s page


Performance I understand, but safety ?

The one possibility for why safety is an issue is that LG likely found a way to increase the thickness of the electrodes through an innovation internally, but without finding a way to offset the internal resistance loss of such a change.

That would mean the cell gets hotter, losing more cycles, and all of the usual stuff during charging, and they don’t want warranty claims because of that.

It looks like a very thin positive terminal that’s already bent/ pushed down near the lower left leg in the picture. Flat tops of many cells are not really designed to be abused and or dropped in flashlights even with springs in both ends.

So first results added to the comparison here: Cycle life tests of High Energy density cylindrical cells | Endless Sphere

Unfortunately, due to the declared larger dimensions D: 21.7 mm and H: 71 mm, the volumetric energy density is only 768 Wh/l and therefore the “magic” value of 800 Wh/l in cylindrical format still resists. :frowning:

I can do measurement and weighing on Monday at first. The EVVA dimensions are max. limit values delcared by LG. It seems that Nkon samples used a thicker tube than LG original tube.

Actual dimensions of Nkon sample:

with tube: D: 21.6 mm, H: 71.2 mm, Weight: 71.8 g (Nkon transparent tube)
without tube: D: 21.4 mm, H: 70.5 mm, Weight: 70.8 g (this cell have an elevated positive terminal)

So without tube and with 20.3 Wh as measured nominal 0.2C energy it makes exactly 800 Wh/l :slight_smile:

Exciting stuff. Thanks for testing it Pajda. This cell probably can’t be stuffed into an S21A it’s so fat.

I measured 5700mah from the cell included with my Sofirn LT1 Mini using a SKYRC MC3000. I wonder if they used this cell and rewrapped it. The positive contact looks to be the same shape. BLF LT1 Mini Review – At Long Last – Grizzly's Reviews

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Thanks for the shared measurements, that looks interesting to me, I’ll order a few.

I’d only buy the cell if you were planning not to draw more than 3A TBH.

You can also check a new thread about simple calendar ageing test results of modern cylindrical cells here: Calendar ageing tests of mixed cylindrical cells | Endless Sphere DIY EV Forum

Anyway, here’s the 1st product that actually seems to use the M58T:

I just searched for LG M58T on Youtube, and found this :stuck_out_tongue:

Also, the M58T’s energy density is quite impressive.

285Wh/kg is nothing to sneeze at.

Hello, are the M58 21700 batteries of nkon disassembled from the equipment? Or is there a brand-new M58 without welding marks?

Dissasembled, Nkon says “These batteries are from a canceled car project”. Brand new M58T cells comes in standard LG tube. !http://evva-tech.com/uploads/220519/1-2205191T32O48.png !