cell_man Li-NCM triangle packs, two sizes now

spinningmagnets

spinningmagnets

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Thanks to ES member popstar for the heads-up:

An article on NCM:
http://www.electricbike.com/lithium-cobalt-magnanese/

Our 14S 9P, 50V 18.5Ah Samsung SDI Battery Pack uses the SDI ICR18650-22P 4.5C rated cell {edit: this cell provides best life-cycle performance when limited to 3C use}
Click to expand...

Pauls controllers now come stock with an anti-spark circuit. For newer members of ES, cell_man (Paul) is a trusted vendor.

http://em3ev.com/store/index.php?route=product/product&path=35&product_id=123
Bag%20in%20Frame-500x500.jpg

EM3ev%20triangle%20bag%20with%20dims-500x500.jpg

14S9P%20Triangle%20with%20dims-500x500.jpg
 
How does it perform under load?
Btw how many amp are you using?

According to this:
http://www.dampfakkus.de/akkutest.php?id=73
The Samsung cells cant even be rated as 3c.
 
Well that's rather interesting that they'd rate the cells that high when they perform like ~2C in reality..

Keep in mind that this 2C graph is how many cells perform at half or a little over half their ratings.

That's why i run 20C lipo at 4C... :lol:
 
I realize that they may actually be a "real world" 2C chemistry, but...2C in an 18-Ah pack is...36-amps continuous? In my mind that makes this a real milestone, and the reasonable price and optional triangle configuration is a great bonus!

Any new vendor, and I would be more cautious, but Paul has worked very hard for a long time to develop and earn a reputation for reliable products, and I trust him at this point.
 
Thanks for the link, the bag measurements, and battery specs. Going to see if this will fit in my surly. I may bite the bullet on this. I really really need to up my current quiver of 24v and 36v electrics. My mind is screaming for me to increase speed into the >25 mph club.
 
Just looking at the graphs, i'd expect this to perform like some of the more stout 2C lifepo4 batteries, maybe a little better... but at much less weight and size.

Would you like to see a discharge graph of the '2C' Allcell batteries these are competing with? :lol: :mrgreen:
 
For anyone for whom the pack shape pictured above doesn't quite fit, Paul is telling me he is trying out a longer slightly shorter shape.

I have a pack on order. The discharge C rate and the cycle life are my biggest worries for this pack over the 20aH A123 packs. I'm hoping though that the easy fit within the triangle of a bike sized to fit everyone in the family will make the big difference from my huge headway on a rear rack.
Its too bad it would be difficult to make a hybrid battery with low weight, low volume NMC for the watthour supply and some A123 cylinder cells in some form of parallel arrangement to "soak up" the peak current draw away from low C cells.
 
Ah, they are Li-NCM. I've a 36V 20aH of this. For those who don't have this chemistry, it tends to slowly drop it's voltage near the last 1/3rd of the discharge cycle, similar to how SLA's feel. Not really sure it makes a difference at 50V performance levels, but at 36V in a 20" wheel @ 15-18mph you start to realize your legs are actually working more, although my legs really weren't working more to begin with 25+ miles into the trip :wink: .
 
Hey Guys,

I just wanted to put my perspective over. Whilst the -22P cells are rated in some places as 10A discharge, I have also seen 3C mentioned. Let's just say it is not so clearly defined. I will always dissuade customers from running very high discharge rates with these cells and I personally recommend users limit max discharge to a little over 2C and try to keep continuous levels a bit lower than that. I would never suggest anyone uses these SDI-22P cells at 4C or close to it.

I also tend to think that these cell types all have a discharge curve that can easily put them below the nominal voltage for a good portion of the discharge curve, so I made a choice to use 14S as my standard rather than normal 13S. 48V/14= 3.4V, so I figure with a 14S pack most users will stay over 48V most of the time. This also means the charge voltage and nominal are more in line with 16S A123. I also offer 17S NCM BMS and will soon have 21S, but not in triangle form just yet.

As this cell type do not have the same sort of lifecycle as A123, I supply a special charger with 3 switch positions for 3.8V per cell (50% SOC), 41.V (90% SOC) and 4.2V (100% SOC) so users can easily reduce the charge voltage if they wish or charge to half charge for storage. All the chargers I describe as Li Ion have this switch included. Such a charger could also act as a dual purpose charger for different packs if some adjustments were made internally, although there is only a limited amount of voltage adjustment available.

I am looking at a couple of other cell options for the future, namely some higher discharge rate 2Ah cells, which would be 20A rated and also some higher Energy density, close to 2.9Ah per cell (200Whrs/kg plus for a finished pack) and still reasonable discharge rate. Both of these options are that bit more expensive per Whr than the SDI-22P cells though. If there is interest in them, I'd be happy to offer packs made from these other cell types in the future.

Thanks
Paul
 
cwah said:
I heard lifepo can loose up to 6%/year and NMC up to 14%/year. Not sure about this one
Click to expand...

:| That's a big deal @ 14% losses per year if it is true. Even at 6%, I personally hesitate to click the "purchase button". If it is, then I better just use this NMC battery I have until it no longer serves it's intended purpose.
 
I like the way Paul works. He tries to be as transparent as possible. :)

Btw I also got a pack made from the same cell, but configured as 17s 16ah.
Should be able to test it in the coming weeks with a 30amp load in a 10t mac.
 
http://em3ev.com/store/index.php?route=product/product&path=35&product_id=123

Could anyone who owns one of these, please tell me if there would be room for this controller inside the bag:

http://em3ev.com/store/index.php?route=product/product&path=38&product_id=81

Does the pack sit forward inside the bag or to the rear?

Thanks
 
A123 is a LiFePO4 chemistry. If you can get authentic A123's they are a good cell. The Li-NCM chemistry would be smaller per the same Ah capacity.

Check the size of any other 18-Ah pack, and this one should compare well when size is an issue. Occasionally cell_man has A123 packs for sale. Compare the size and prices of the two packs and choose what works best for you.
 
spinningmagnets said:
A123 is a LiFePO4 chemistry. If you can get authentic A123's they are a good cell. The Li-NCM chemistry would be smaller per the same Ah capacity.

Check the size of any other 18-Ah pack, and this one should compare well when size is an issue. Occasionally cell_man has A123 packs for sale. Compare the size and prices of the two packs and choose what works best for you.
Click to expand...
Yea I wish there was a triangle pack made with A123's.
 
cell_man said:
I just wanted to put my perspective over. Whilst the -22P cells are rated in some places as 10A discharge, I have also seen 3C mentioned. Let's just say it is not so clearly defined. I will always dissuade customers from running very high discharge rates with these cells and I personally recommend users limit max discharge to a little over 2C and try to keep continuous levels a bit lower than that. I would never suggest anyone uses these SDI-22P cells at 4C or close to it.
Click to expand...
Very commendable!

But what would make it outstanding is the genuine datasheet from Samsung along with a 2C discharge graph with cell temperature. Then there would no longer be any doubt and/or speculation. As far as I can tell, the "ICR" is simply Li-Ion (I) Cobalt (C) Rechargeable (R). Which means the cell will get EXTREMELY hot at 2C continuous, and less than 70% of the capacity can be drawn at that rate. There is NOTHING to indicate it has Nickel and Manganese in it. I would never run ICR cells continuously at a rate higher than 1C.

In fact I have in front of me Samsung's own Nickel (Manganese) 18650 cells. They are labeled INR. Note the "N" instead of the "C". I have tested these cells at 3C continuous and they do deliver full capacity at that rate. Push it to 5C and they become hot and capacity is greatly reduced.
 
gensem said:
I like the way Paul works. He tries to be as transparent as possible. :)

Btw I also got a pack made from the same cell, but configured as 17s 16ah.
Should be able to test it in the coming weeks with a 30amp load in a 10t mac.
Click to expand...

That's why i'm a big cell_man/em3ev whore. Paul is engineering-minded and tells it straight.

Curious to see how they do. I usually refer people to pingbattery but these are lighter, smaller, and priced close enough to be a better deal all around.
 
gensem said:
According to this:
http://www.dampfakkus.de/akkutest.php?id=73
The Samsung cells cant even be rated as 3c.
Click to expand...
How did I miss this post? If the discharge graphs in that link is real (and I have no reason to doubt it), then this cell CANNOT even be rated at 1C! Pathetic! At 2A (0.9C, NOT even 1C) it only delivers 2057mAh or 94%.
 
Yep, 2.15ah is only the best case scenario. You will find that all proper cell spec sheets will mention this.
At 1C continuous, it looks like you get 2.05AH.

http://www.panasonic.com/industrial/includes/pdf/UR18650F.pdf

Here is a spreadsheet for the Panasonic cell used in the allcell batteries. These are sold as being 2C, but perform like a 3.3v nominal cell and deliver about 2450mAH. 2600mAH is outputted at a 0.2C rate.

Batteries should always be overrated for the job at hand. You will always get the most capacity / performance / life out of a battery by taking the manufacturer's max figures for discharge and cutting them in half or even fourth.
 
I am almost finished with my build using this pack and will put more info in the build thread soon http://endless-sphere.com/forums/viewtopic.php?f=6&t=49099 including the lockable battery harness.
Here is a picture of the triangle pack below my sideways 16in Gary Fisher Frame. You can see there is lots of room, although since the pack is 8inches behind the frame i think the picture makes the battery look smaller than it is.
14s9p triangle batt in 16in Fisher.JPG
Here is a picture comparing cell_man's 14s9p triangle pack to my 36V 12ah Headway battery from BMSbattery http://www.bmsbattery.com/packs/154-36v-12ah-38140-lifepo4-battery-12-cells-ebike-battery-pack.html
14S9P triangle vs headway 36V 12ah 02.JPG
It is pretty impressive that this battery is the same size as the headway, but with double the WHrs.
 
Yup. Headways are laughably huge. I couldn't even fit a 36v/12AH headways pack into what i normally stuff a 36v30AH RC Lipo pack into.

What cell_man is selling is very close to RC Lipo size/weight.
 
There seem to be very conflicting views here. From my reading on ES, cell_man seems to be a fairly universally trusted vendor who makes well-engineered battery packs. But some of y'all are saying that these batteries can't do half of what cell_man claims they can do. It even sounds like some of y'all might be suggesting that these batteries would get really hot in "normal" use, possibly unsafely so? While others seem to think this is a great battery pack made from good cells. Would this pack get really hot if run at 2C/36amps continuous? I'm far from being an expert on these things, so someone please school me on this. :? Anyone have any real-world tests yet?
 
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