Molicel IMR-26700A/AB

[methods]

That is pretty standard.... The Hobby City Lipo is good for about 250 cycles IIRC. What is important is how they rate the life. Could be the point where it only has 90% capacity, or 70%... It is not like they work 300 times and then just die

Ignorance is pretty much bliss and I think you will find that most people have no idea how many cycles their cells are rated at.

Cycles are also misleading... a cycle is a hard swing from HVC to LVC to HVC. That will cause much more wear and tear than a reasonable ride from 4.0V to 3.3V to 4.0V. Only a tard cycles their cells down to LVC. By short cycling your cells last forever - I am still running the original white-shrink hobby city cells I bought for my first electric scooter years ago.

-methods

[SlyCayer]

Tests...

As of now, it's not looking too good...

I just did a test on 2 cells separately 4 times:

Cell 1 at 1C: 1.05Ah, 1.06Ah, 1.15Ah and 1.01Ah.
Cell 2 at 1C: 1.69Ah, 1.65Ah, 1.65Ah and 1.65Ah.

At least I can say they are constant with the Ah... These cells we're from one battery so please let me open more and test the cells out of other batteries.

I will also change my testing method. I am currently using a "high resistance" way of testing them with long small wires between the tester and the cells...

I will shorten the wires to bare minimum and see if it makes a difference.

[liveforphysics]

Tests...

As of now, it's not looking too good...

I just did a test on 2 cells separately 4 times:

Cell 1 at 1C: 1.05Ah, 1.06Ah, 1.15Ah and 1.01Ah.
Cell 2 at 1C: 1.69Ah, 1.65Ah, 1.65Ah and 1.65Ah.

At least I can say they are constant with the Ah... These cells we're from one battery so please let me open more and test the cells out of other batteries.

I will also change my testing method. I am currently using a "high resistance" way of testing them with long small wires between the tester and the cells...

I will shorten the wires to bare minimum and see if it makes a difference.

Definately need to 4 wire it. Or use as short and fat of wires as you can.

[SamTexas]

Cell 1 at 1C: 1.05Ah, 1.06Ah, 1.15Ah and 1.01Ah.
Cell 2 at 1C: 1.69Ah, 1.65Ah, 1.65Ah and 1.65Ah.

1) At what voltage did you terminate the test? What was the cells' voltage after 5 mins rest? For laptop LiCo cells, I terminate the test at 2.50V. After 5 mins rest, the cells' voltage recovered to about 3.50V.

2) What were the cells' voltage at the beginning of the test? I charge the laptop LiCo cells to 4.20V before testing.

I will also change my testing method. I am currently using a "high resistance" way of testing them with long small wires between the tester and the cells...

I will shorten the wires to bare minimum and see if it makes a difference.

It will make a difference, but not a big one for sure. You were testing only one cell at the time. At 1C, the current is only 1.0A and 1.7A respectively, so the wires' size and length matter only a little.

But these are high discharge cells, so I think most people are interested in 4C and up discharge tests. For 1C, people would be much better off with laptop LiCo cells which have much higher energy density.

[SlyCayer]

1) At what voltage did you terminate the test?

2.8V

What was the cells' voltage after 5 mins rest?

back to 3.7V

2) What were the cells' voltage at the beginning of the test? I charge the laptop LiCo cells to 4.20V before testing.

4.2V-4.3V

It will make a difference, but not a big one for sure. You were testing only one cell at the time. At 1C, the current is only 1.0A and 1.7A respectively, so the wires' size and length matter only a little.

But these are high discharge cells, so I think most people are interested in 4C and up discharge tests. For 1C, people would be much better off with laptop LiCo cells which have much higher energy density.

You are 100% right it didn't change anything, reran a test with Cell number 2 and got 1.71Ah which is still FAR from 2.9Ah.

I will be running further tests on multiple cells from multiple packs and let you guys know.

I do all of this for the fun of testing and find out more interesting stuff...

I will be testing Milwaukee's M18 cells(Red-Lithium) which are supposedly a lot better.

[cassschr1]

Red lithium ,hum, do you mean 18650 cells or 26700, 18650 red is probably sanyo and the only 26700 I've seen are a brown or white cardboard. Hope your testing gets better capacity than the three hundred I tested

[gblast123]

I believe that they are the 18650 W2 cells from Sanyo. They have something like a 5c or 10c discharge rate and are 1.5Ah.

Pretty hardy cells.. they are being used in the Ridgid tool line.

[liveforphysics]

Whoa! Hopefully you just happened to have picked some duds from the bunch when you tested? Or did you test a bunch and got dud results?

Methods and I both have over 1,000 of these moli-cel 26700 LiMn cells in new condition that do test over 2.5Ah. I personally don't sell things like that, only give it away to folks who do things that impress me.

Methods sells his I believe though.

[nebriancent]

you think i could impress you by taking my bike into a large steel cable deck mount on a car bridge at over 60k and only damaging my ca and front rim(besides my pride and body) j/k

so how many cycles do you think we would get at a much more conservative charge and discharge on the cells??

[liveforphysics]

you think i could impress you by taking my bike into a large steel cable deck mount on a car bridge at over 60k and only damaging my ca and front rim(besides my pride and body) j/k

so how many cycles do you think we would get at a much more conservative charge and discharge on the cells??

If you get it on video so I can enjoy it, I would totally dish out cells for that. Watching ebike parts explode into plasma, watching batteries burn on bikes in public, watching human bodies thrown from ebikes cartwheel and flip and slide and tumble, etc. Those are all the things on here I like to see.

I mailed off a premium 1.3kw-hr ebike battery this week all ready for free to a very deserving awesome person on this forum.

[nebriancent]

no video plasma or fire just a lot of bent and broken parts in the front end

**edit the thing that realy impressed me was the bike still turned on, spun up, lights all still work, and after folding the front rim in half i didnt get a flat or kill my shocks:)

already fixed - front rim, CA, front brakes, wiring to CA,

had to make a hole new bottom end for my CA
i used some extra plate at work last night and made a mounting point out of a few nuts and a couple of bolts
but... now im geting a dead line thru the ca i meen it all works just one line in the display dosnt function
eg

xxxxxxxxxxxxxxxxxxxxxxxxxxx
xxxxxxxxxxxxxxxxxxxxxxxxxxx
xxxxxxxxxxxxxxxxxxxxxxxxxxx

xxxxxxxxxxxxxxxxxxxxxxxxxxx
xxxxxxxxxxxxxxxxxxxxxxxxxxx

any ideas on what it could be...
mabee just a bad connection to the lcd board in one part or somthing???

[beast775]

damn it! i just had my front fender brace lock up my front wheel,i need a vid cam.thats awesome to hear LFP .

[heathyoung]

A dead line on the LCD is caused by the rubber strip between the LCD glass and the circuit board underneath it. These are crimped at the rear (the metal 'tangs' onto the PCB) - sometimes moving these fixes the issue, otherwise the LCD is a standard 16X2 unit.

[cassschr1]

Luke, in testing those cells about the highest was 2050 ma with most at 1300 to 1700, and a whole lot of just dead ones. At one point I had taken apart 40 milwaukee V28 packs and every f.....g cell was bad. Ridgid 24v were better. Both have the same BMS manufacturer. I built four packs of moli 12s4p with every cell tested by itself , 192 cells . This is all on one TF on the top tube. I wish my cells delivered 2.5 ah

[SlyCayer]

P.S: Milwaukee M18 Red-Lithiums are not Sanyo, they are Samsung INR18650-15M

I will be performing tests on these to see the max discharge current.

[nebriancent]

A dead line on the LCD is caused by the rubber strip between the LCD glass and the circuit board underneath it. These are crimped at the rear (the metal 'tangs' onto the PCB) - sometimes moving these fixes the issue, otherwise the LCD is a standard 16X2 unit.

thanks i was thinking that the rubber sh%# might be the problem

ill have to give that a try on the weekend as i have sealed my unit of w/ silicon and don't feel like going through the bother till then

[methods]

....
Methods and I both have over 1,000 of these moli-cel 26700 LiMn cells in new condition that do test over 2.5Ah. I personally don't sell things like that, only give it away to folks who do things that impress me.

Methods sells his I believe though.

That is because I am a money grubbing energy whore.

-methods

[SlyCayer]

That is because I am a money grubbing energy whore.

LoL

[SlyCayer]

Took about half of the cells out of packs...

[Kin]

Woah, four screen work station?

[SlyCayer]

Woah, four screen work station?

Yeh, I might have 4 more coming that will be 2 high by 4 wide.

[SlyCayer]

Alright,

Test Cell 3 and 4 choosen very randomly scored a high 2.09 and 2.15Ah at 1C.

Is it possible that at like 7C the battery can't just take it?

The test went on for only like 2 seconds??

[SamTexas]

7C is 20.3A per cell, right?

That's only half of the maximum 40A claimed rate. Disappointing for sure but not totally surprising considering the common practice of over advertising. So do you plan to continue testing at lower rate? 5C, 4C...

I wonder if people who bought HK super duper high discharge RC Lipo batteries (50-100C) have ever actually done any testing at all.

Edit: I just went back to look at the discharge graph in the data sheet you provided:

Please see: http://www.molicel.com/ca/pdf/IMR26700.pdf

They did have discharge data at 20A (red) and 30A (black), and the capacity is only about 15% less than 3A discharge. So it looks like you have problem with the test equipment.

[methods]

Emoli cells are good to about 3C in the real world. If you want high discharge then buy Lipo.

-methods

[liveforphysics]

Emoli cells are good to about 3C in the real world. If you want high discharge then buy Lipo.

-methods

+1

The datasheets on these cells were written by a dreamer.