SAMSUNG INR18650-29E cycle test.

Offroader said:

I'd like to see this thread about charging but I believe it is understood that higher charging rates, even if below the battery spec, seems to do a lot of damage.

This is why I usually charge my cells at around .2C charge. I don't care most of the time if it takes 2 hours of 8 hours to charge my pack.

My 18650GA samsung cells are rated at a 1.6 amp charge rate per cell (about .5 C charge), but since I have 14 of them in parallel, I don't care about charging them at .7 amps each cells. Still gives me a 700 watt charge rate because my pack is so large. It also still heats the pack up by a decent amount at that low charge rate.

But if one was to use these 18650 GA 3500 cells and charge them at 1.5 amp per cell, I agree you would get diminished life from the. I only know of one person who charged them above spec at like 3 amps per cell, and he got greatly diminished capacity.

Discharge at higher rates is probably not that much better, but most of us pulse the discharge when riding. If one was to run it full rated discharge, even half the rated discharge, you would probably get reduced capacity quickly, and a very hot battery.

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There was some discussion and tests done in this thread on various cells: https://endless-sphere.com/forums/viewtopic.php?f=14&t=68556&start=100

Both at high 1C charge currents where cycle life was garbage, and also 1C with 85% DOD.

Also we know Tesla super chargers are charging at around 1.5C+. They are using cells similar to the NCR18650BE/BD. The cells they are not using are not magical or anything. But guess what, go ahead and try to some cycles on some Tesla cells or even similar Panasonic cells at 1 to 1.5C with a 4.20v CC/CV charger. I guarantee you, you will see massive massive capacity losses after 100 cycles. Yet there have been Tesla's with 150-200K miles on them where they were only charged using super chargers and they still have decent capacity left. I think the trick is in the charge voltages at or around 4v and higher. I believe Tesla doesn't use CC/CV but uses something like what I described in my last post, they start reducing the current much quicker than a normal CC/CV charge method. And I'm sure a little chilled liquid cooling on the battery pack helps also.

Doesn't Tesla have that "standard". and. " range". charge options ?
I.E., in normal use they limit the charge capacity/voltage to something less than maximum.

Hillhater said:

Doesn't Tesla have that "standard". and. " range". charge options ?
I.E., in normal use they limit the charge capacity/voltage to something less than maximum.

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You can definitely limit the charge % within the settings of the car. My friend has one which I've ridden in and I think he changed it to like 90% or something be default. If he takes a long trip he can crank it up. But I was mainly referring to what the super chargers do, which is a fast charge at around 1.5C with about an 80% SOC. 30 minutes and 200 miles range I think is what they claim.

DrkAngel said:

Hillhater said:

..fair comments guys, but..
...There is no data to quantify any capacity loss due to the higher charge rate.
..and true , Redilast,...those capacity maps are only representative for the one discharge rate ...0.2 A
..and the one used (0.2A discharge) , is not relavent to these tests.
DA,..do yo have any higher rate discharge capacity maps ?

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Capacity loss from higher charge voltage, mirrors capacity loss from known damaging higher charge rate! = data indicates capacity loss due to the higher charge rate.
My "Capacity maps" are tasked to indicate capacity at static voltages and so are created at the minimal discharge rates to reflect best accuracy.
Capacity maps are produced to help determine optimal charge voltages
and
to help determine optimal discharged voltage ... not discharge voltage, discharged voltage.
Resultant voltage after discharge concluded.
Discharge voltage would be continuously variable, unquantifiable except for at a specific motor x rpm + controller x throttle position + battery condition x actual capacity

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Good grief Hillhater, drkAngel is completely right in his statements..
I thought untill reading your post what he was saying (and I have repeated it many times now) is now basic common knowledge on this forum for at least the last year or so for everyone, this is basic stuff next to absolute charge voltage limit is 4.20 for 18650 etc.
There has to be at least 5 separate threads that are pretty much dedicated to the fact that high charge current rates kill cells quickly.
I like you but I think you should be banned and have your IP permanently firewalled from even reaching this forum server for spending so much time on here and not knowing this stuff, charge rates are ultra important.

TheBeastie said:

.....There has to be at least 5 separate threads that are pretty much dedicated to the fact that high charge current rates kill cells quickly.
.

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That is true, but none of them duplicate the cell, or test scenarios used in these tests, so cannot be considered as supporting proof.
Further, the term "high charge rates" is pretty loose and subjective.
What is considered "high" for one cell type may not be so for another.
but my basic point was these tests produce no data to confirm that the charge rate used was the cause of the capacity loss. !
..it MAY be the cause , but the data doesn't confirm that.
Personally, i also doubt that a cell charged at a fractional C rate ( 0.65C, in this case) should suffer significant capacity loss...but again there is no data to confirm that.
and Ditto for the 4.2 charge voltage.
as has been said several times previously, a different set of test parameters would be needed to produce data to indicate those effects.

So when DA states..
.."

Capacity loss from higher charge voltage, mirrors capacity loss from known damaging higher charge rate! = data indicates capacity loss due to the higher charge rate

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..i would question,.. how do we know 0.65C is a "damaging" charge rate for these cells ? ..( again, its MAY be..but we dont know that for certain without testing, and it certainly has not been quantified )
..and so to state the capacity loss is due to the charge rate,..is purely an assumption, and not proven by the data.
DA is a respected, experienced,poster with a huge catalog of information to his credit, and i respect that and only question his input for clarity
There is a tremendous amount of useful information on this site and others, but i long ago learned to base conclusions on facts and data, not on internet chat or repeated forum statements no matter how genuine the author. Even firm data needs to be questioned at times as its easy to record false results.
i would worry if no one questioned information posted here, and would worry even more if anyone was sanctioned for questioning "accepted facts" .
Maybe that Melbourne heatwave at the weekend got to you Beastie ? :wink:

Any results on your 29E cycling test?

All the nitpicking and bickering like geeky old ladys. What is the conclusion to the cycle test? Are the 29Es decent ? Im gunna run 2 36v in series in a few minutes here. I noticed the Ford Go Bikes are using the 29E batteries. hehe

stuffc said:

Im gunna run 2 36v in series in a few minutes here.

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36V 10s2p recommended for 5.5A continuous use, up to 16.5A max, brief discharge.

36V 5.5A = 198w battery output ≤160-180w motor output

they will lose capacity when ridden hard:

https://drive.google.com/file/d/1AWTQlij0X1qYCiamB4hx25xNOyC0tWGd/view?usp=sharing

but these things are bascially unbreakable when keeping within spec:

https://drive.google.com/file/d/1v8PGphx0BzGzPJsUpUzXVG9fTgijW61g/view?usp=sharing

The Ford go bike ones are 36v and 11ah . Dont seem too exciting. Maybe ill try 3 in series.

DrkAngel said:

stuffc said:

Im gunna run 2 36v in series in a few minutes here.

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36V 10s2p recommended for 5.5A continuous use, up to 16.5A max, brief discharge.

36V 5.5A = 198w battery output ≤160-180w motor output

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for give my ignorance but are these in series worth playing around with ?

I was thinking that this is probably one of the most interesting in house 18650 cell cycling tests to see total capacity over time I have seen.

I was wondering if I have missed subsequent tests on ES forums, that would be for any lithium cell, not just 29E..
Has anyone else done tests like this? I am really interested in 500+ cycle tests to see the total mAh thats left over..

What is the conclusion for 29E?

I think for high discharge rate, and a decent capacity the 25R is a good choice, and good alternatives perhaps the VTC6?
But what about higher capacity which always means lower discharge rate, the 29E would be top 3 if not #2 because its 8.25A not 10A like PF?

markz said:

What is the conclusion for 29E?

I think for high discharge rate, and a decent capacity the 25R is a good choice, and good alternatives perhaps the VTC6?
But what about higher capacity which always means lower discharge rate, the 29E would be top 3 if not #2 because its 8.25A not 10A like PF?

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https://endless-sphere.com/forums/viewtopic.php?f=14&t=93989&start=25#p1459171

electricbike said:

Uppdated +150 cycles.

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I just registered to say thenk you! It's 2020 and after 4 years your data helps so much, I really apreciate your tests