3500-mAh NCA cell, Samsung, LG, Sanyo, Panasonic

Testing a bunch of cells now, and I am coming up with a win for the Samsung 29E. Not the highest capacity or the highest discharge, but the price to overall performance seems to be one of the best.
Anyone think there is a better value cell out there right now?

Looking at building packs in the 16S-20S range and 6P-8P range for the MXUS 3000W Kits we are selling. 40A-60A Discharge rate, typical, so 5A-10A per cell.
 
Are these 3.5Ah cells the same physical size as ~2.25Ah.
Im sizing up my a123, and these things are huge.
If I can find a decent 3.5Ah thats the same size as the 2-2.5Ah cells then that is a bonus.
 
The 18650 designation means 18mm diameter, and 65mm long, the last zero means a cylindrical cell. Another common size is 26650, same length, but fatter. An 18350, is same diameter, but shorter.

AA batteries can be found in rechargeable chemistries as a 14500.

You can also find very large cylindrical cells, Headways are famous, a 38120 is pretty huge.
 
markz said:
Are these 3.5Ah cells the same physical size as ~2.25Ah.
Im sizing up my a123, and these things are huge.
If I can find a decent 3.5Ah thats the same size as the 2-2.5Ah cells then that is a bonus.
Click to expand...


No, they are smaller, same length, but smaller diameter (18 vs 26 mm). You can find a more than decent 3.5 Ah cell smaller then 2.25 ah cell, it's actually half the volume of 26650 cell :D And half the weight too.
 
Yeah I mean seriously, a brand name 18650 ~3.5Ah in a 15A discharge flavor for a reasonable price. I think us eBikers would be all over that.
 
Free loose cans are the best.
I am never buying an already tab welded pack ever again.
I have 93 tab welded cans to go.
My next batch are high density, which I assume are the higher Ah batteries. Higher energy cells are the higher discharge cans/cells right?
 
This is a few years down the road before we can actually buy them, but Solid State Batteries (SSB), will double Ah per volume. High- amp output also seems to be a characteristic that is a side-effect of designing batteries that can be charged fast, and fast charging is a major benefit with a tremendous amount of market pressure on it to continue improving...
 
teslanv said:
Testing a bunch of cells now, and I am coming up with a win for the Samsung 29E. Not the highest capacity or the highest discharge, but the price to overall performance seems to be one of the best.
Anyone think there is a better value cell out there right now?

Looking at building packs in the 16S-20S range and 6P-8P range for the MXUS 3000W Kits we are selling. 40A-60A Discharge rate, typical, so 5A-10A per cell.
Click to expand...

Do you have a spreadsheet showing $$/Wh or $$/lb for the different cells.....How did you come up with 29E as best value?

Tim
 
I am coming up with a win for the Samsung 29E.
Click to expand...
Yes at 2900mAh and a bunch of loose cans to make 72V 9Ah, is only ~$250 shipped.
You got me re-interested in those 29E's, but the Sony V3 and VTC4's are the same price. Sony with 800mAh lower capacity, but trade it off for higher discharges.
I am fed up with untabbing my a123 40V 16Ah bus pack, but it will fit very nicely into my battery holder with a sheet of Home Depot Duraplex, and Epoxy.
Going to make it so the modules just slide in and out easy. 8S charging will be a challenge, but the 72V charger will be easy.
I have half taken apart, so the 18650 smaller then 26650, so for the 18650, I believe I can get twice as many in, so amazingly 18Ah 72V for 29E, the rest will be 15Ah. So either 27Ah pack or 24Ah pack, I think will suit my needs just fine. The smaller size cells are all no name.
 
Yeah so in a series cct, whatever your discharge is for that cell, 10A for the 29e or 20A for the 25r, thats what it is also for the output of the series cct.
If you want a 40A continuous discharge for your motor, you at a minimum need 4 parallel strings of 29e (10Acont discharge).

However the higher your voltage is in the series cct, the less each individual cell will see in terms of current draw from the single cell.
For example,
Lets say you are rocking four 29e cans in series, you have ~15V and 9Ah, so 4S3P. Your amp draw for continuous is 40A.
40 divided by 3 = 13.3A divided by 4 = 4.50A per cell. Or 0.5C

On the other extreme, lets say you are rocking 8S6P. 40Acont.
40/6=6.67A/8=0.83A/cell lets round up to 1A or 0.1C. For 40Acont.

Thats the way I look at it, is that right or wrong? It makes sense to me.
If I am doing it wrong, whats the calculation and formula?
 
How will NCR18650GA feel at 65A peak with 7p is this ok or will this be cell raping?
Click to expand...
According to some tests published here and on the cigarette forum, GA cell is behaving as the old PF cell, and is good for about 15A~18A peak. 65/7=9,2A, so you are safe. I'm using PF in 2p configuration at 14A~20A (10A per cell peak) for 1,5 years now and the range is the same as it was the first day. Those peaks are maybe 5% of its duty cycle, most of the time the cells are seeing very low currents (unless that youtube video of the wild ride in Stockholm is yours;) ).

By the way, vi får fixa en ebike träff i Sverige snart ;).

image-jpg.489396
 
So after reading all 3 pages, what's the concensus?? Forget about money. I care about density and power to weight ratio. Is the 35E holding up to 29E?
 
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