NMC 26650 cells anybody got these from batteryspace?

[migueralliart]

I was looking at the batteryspace li-ion inventory for 26650 sizes and I think this cell is really interesting...

http://www.batteryspace.com/High-Power- ... -Rate.aspx

It seems I can do a 14S2P 7.2Ah 51.8V pack for 259$ shipped with coupon code E7SEA this pack should be capable of 36 amps discharge and really small... looks like I've found my replacement triangle pack for my current 18650's pack which in turn will become the wifey's new bike battery pack

Anybody had any experience with these?



UPDATE: May 16th,2012

Got 3 cells 3.6Ah 26650 from batteryspace. Shipped via USPS priority mail with tabs for 9.75$ each.
Did a full balance charge and then a 1C discharge test. I was impressed with the accuracy of battery space discharge graphs and capacity tests. My icharger needs calibration so I won't post any discharge graphs right now. I will try to calibrate it this weekend and do some 2C-5C discharge tests with capacity to give the forum members an idea of what to expect. Overall my first discharge test I got ~3,300 mah at 1C and my icharger stopped at 3.4V under load (measured with both a fluke and a radioshack meter).

I'll keep this first post updated as I do more tests with them.

[Ypedal]

Buy a few, test them yourself, and report back !!! ..before investing into a bunch of $$$ and finding the " real " specs.... batteryspace is famous for lying thru their teeth on specs.. imo.

[migueralliart]

Buy a few, test them yourself, and report back !!! ..before investing into a bunch of $$$ and finding the " real " specs.... batteryspace is famous for lying thru their teeth on specs.. imo.

Well thanks for your suggestion... I think these cells might be what some of the NMC packs use. The ones in ebay. I have a good stock of A123 cells, but sadly they are not good for my application because I don't have a high amp controller in my commuter. What I am looking to do is maximize the power/size ratio for my commute but staying away from lipo. So far my pack has given me good results but it has a low discharge rate. For my commute I use only 4Ah off my 36V battery. I was thinking of maybe building a high voltage pack with A123 to increase speed a bit. But my triangle space is not that great. If I could have a 14S2P pack in there even at 7.2Ah I'm pretty sure I can make it roundtrip, due to the higher voltage consuming less amps. Plus I can charge at work

There's gotta be someone in this forum who had purchased these cells...

[Brentis]

Buy a few, test them yourself, and report back !!! ..before investing into a bunch of $$$ and finding the " real " specs.... batteryspace is famous for lying thru their teeth on specs.. imo.

Perusing the site I find.
Prices are a lil' on the high side , these cells excluded.
Compared to what is available elsewhere.
HK, BMSBatt. Cell_man, etc.

No experience with them though, sorry.

[migueralliart]

I think those cells are not that expensive considering the size and capacity, sure you can get a better price going lipo but life is not THAT great... these cells are supposed to get more than 1500 cycles which to me is great considering is a higher voltage cell when compared to lifepo4

[Ypedal]

nothing says you canot get 1000+ cycles from lipo, if you use them at ebike type power levels... ( like.. normal ebikes.. forget luke's bike of death... )

[migueralliart]

Well I'm thinking about doing a cell discharge shootout test what do you guys think? I can purchase 1 of each type and settle this uncertainty.

Cells will be;
18650 NMC 1.5Ah 22.5A rate
http://www.batteryspace.com/new-generat ... 00mah.aspx
26650 NMC 3.6Ah 18A rate
http://www.batteryspace.com/high-power- ... -rate.aspx
26650 LiMnNi 4Ah 4A rate
http://www.batteryspace.com/limnni-rech ... 4.8wh.aspx
26650 Lifepo4 A123 2.3Ah (whatever rate)
own stock


To do this and control the results, I'd probably run a discharge test with the icharger 3010+ using the discharge+ setup for a single cell and discharging into an empty SLA or a group of empty A123's

[Brentis]

Great Idea.

Can I suggest 2 or 3 cells of each.
To cover/check variations, prevent a dud cell contaminating test results, etc.
Little more expensive, but better science.

[Ypedal]

hell if you have the proper bits, knowhow, and time to test and the will do to it.. i'd paypal some funds to the cause !

[migueralliart]

Well I have the time to do these tests and the tools....

Any other cells you might wanna add to the order? I'm gonna keep LiCO apart and lipo cause we have already seen those alot....

[Brentis]

All the same choices I would have made with the addition of,
http://www.batteryspace.com/LiNiCoMn-18650-Cylindrical-Rechargeable-Cell-3.6V-2000mAh-7.4Wh-6.0A.aspx
Maybe.

[migueralliart]

All the same choices I would have made with the addition of,
http://www.batteryspace.com/LiNiCoMn-18650-Cylindrical-Rechargeable-Cell-3.6V-2000mAh-7.4Wh-6.0A.aspx
Maybe.

Yeah I thought about adding that but I'd have to call to order it ... perhaps I'll just make a phone order then.

You guys think I should make a thread about this ?.. it might be useful information in the future for people here in E-S

[Brentis]

Absolutely
I wish I could contribute financially
I'll definitely follow such a thread & appreciate its value.

[Brentis]

...
... perhaps I'll just make a phone order then.

...

I think this is best.
It is a good way to develop a rapport/feel out this vendor, for the ES community.

Good luck.

[Ypedal]

might want to check with liveforphysics.. he may already have a bunch of those in a box... something tells me this is highly possible...

[texaspyro]

They call them 3600 mAh, but their own spec sheet shows them to start at around 3200 mAh (and drop steadily).

[migueralliart]

They call them 3600 mAh, but their own spec sheet shows them to start at around 3200 mAh (and drop steadily).

Their pdf shows more than 3700 mAh @ 18amps discharge
http://www.batteryspace.com/prod-specs/6459_6.pdf

I guess Im ordering this afternoon and start a thread for donations in case somebody else wants me to test some OTHER cells from their website. I'm willing to put the majority of money into it just for learning and discovering the truth so that newbies don't waste their money and be well informed.

[Ypedal]

if you do this, pls show your work and methods. so if something is not right we can figure it out ( test methods, equipment, temps.. etc.. )

[migueralliart]

if you do this, pls show your work and methods. so if something is not right we can figure it out ( test methods, equipment, temps.. etc.. )

Before I do it thou,

The only way for me to do a discharge test is with the icharger 3010b+ , I believe this is an acceptable method for logging deltaV @ ~ constant current(with logview). The problem will be measuring the internal resistance with the icharger as it is not really THAT accurate. We can do something like this:

Discharge @ 1C
Discharge @ 5 C
Discharge @ 10C

Discharge @ max discharge current specified

for controlling the results I could charge each one to their specified charged voltage let it sit for half a day and then discharge. Do maybe 2-3 cycles and then record the run since these are new cells.

Then also do some instant pulse logging @ max discharge for a couple of cycles continuously and measure temperature.


And later we can do discharge @ different temperatures.


I like this kind of work, if someone has other ideas please chime in before we start this whole exercise.

I can post videos and all if there is enough support. I'll definitely post discharge curves like the ones I've done with the A123 I'm selling.

[migueralliart]

All the same choices I would have made with the addition of,
http://www.batteryspace.com/LiNiCoMn-18650-Cylindrical-Rechargeable-Cell-3.6V-2000mAh-7.4Wh-6.0A.aspx
Maybe.

This cell is not in stock , I called to see if I could order it but they don't have it. I could order NMC cells from them and then order the other ones from all-battery. I've ordered from both in the past and have good experiences.

for 18650 with at LEAST more than 5amp discharge
http://www.all-battery.com/lgchemli-ion ... 038-0.aspx
http://www.all-battery.com/SamsungLi-Io ... 30612.aspx
http://www.all-battery.com/3-6v1300mahl ... ttery.aspx

Need your feedback guys ....

[Lemlux]

In the single cell 18650 universe, at least, I'm aware of various chargers that cut off at 4.2V for cell protection. On other forums I've read many confused posters wonder what to do with cells like the referenced higher capacity Samsung cells with cutoff at 4.3V and the LG with a 4.35V cutoff.

I suppose that the Samsung and LG cells require very specific BMS HVC's.

I recall reading posts that the Samsung cell delivered considerably less than the rated output when charged in a standard 4.2V cutoff charger.

Comments?

[migueralliart]

Updated first post !....

It's been a while but at least I got the cells tested.