# Batteries For a Bicycle



## major (Apr 4, 2008)

sunworksco said:


> I have been reading about this battery and it seems to be promising.
> Has anyone had good comments?
> 
> http://us.itselectric.ca/product_p/48v- ... r-10ah.htm


Your link was broken. I assume you mean this: http://us.itselectric.ca/product_p/48v-lithium-polymer-10ah.htm At $1.45/Wh and 137Wh/kg, what is it you find promising?


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## sunworksco (Sep 8, 2008)

Tesla, Nissan and Panasonic rate the highly.
What would be the best to use for performance?


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## major (Apr 4, 2008)

sunworksco said:


> Tesla, Nissan and Panasonic rate the highly.


The only similarity between batteries of Tesla, Nissan, Panasonic and this place (ItsElectric.ca) is the Lithium. It is unclear what is inside the package from ItsElectric, but my understanding is Tesla uses 18650 NCA and Nissan uses pouch NMC.


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## sunworksco (Sep 8, 2008)

I was getting info from this www.electricbike.com article:

NMC/LiNiMnCoO2/Li-NMC-O2-Lithium Nickel Manganese Cobalt Oxide
Battery manufacturers are continuing to research for developments in dozens of battery chemistries, and a couple of years ago, a big improvement to LiPo/LiCo chemistries began to be produced. A high-Cobalt cathode (LiCo) provides very good power density, but how can we make it more stable and reliable? Here’s a quote from batteryuniversity.com
“The secret of NMC lies in combining nickel and manganese. An analogy of this is table salt, in which the main ingredients of sodium and chloride are toxic on their own but mixing them serves as seasoning salt and food preserver. Nickel is known for its high specific energy but low stability; manganese has the benefit of forming a spinel structure to achieve very low internal resistance but offers a low specific energy.
Combining the metals brings out the best in each. NMC is the battery of choice for power tools and powertrains for vehicles. The cathode combination of one-third nickel, one-third manganese and one-third cobalt offers a unique blend that also lowers raw material cost due to reduced cobalt content“
Some of the NMC sellers are advertising their chemistry as 5C, but real-world use by E-bike builders has them calling NMC a solid reliable 3C chemistry, which can provide a continuous 30A from an affordable and compact 10-Ah battery (temporary peak amp-draws can be higher, as it is with any of these chemistries). This may sound only as good as the most recent LiFePO4, but NMC is smaller, and is not as fussy about keeping the individual cells balanced.
A recent quote from ES member SamTexas on claimed max C-rates: “…I have in front of me Samsung’s own Nickel (Manganese) 18650 cells….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…“
You can actually buy an E-bike NMC pack right now, but it remains to be seen which retailer will prove to be the most reliable. An NMC pack will be about 25% smaller and lighter than an equivalent LiFePO4/LiMnO2 pack. The extensive testing done by Zero, Tesla, and Nissan gives us a great deal of confidence in the safe and effective use of NMC over the next year…


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## major (Apr 4, 2008)

I wish articles would be dated. I think your reference there is a few years old. Tesla has moved past NMC and into NCA (nickel cobalt aluminum(LiNiCoAlO2) cathode chemistry from Panasonic) for the Model S. Don't get me wrong, NMC is great. I like it, and use it, and recommend it. But it comes in many flavors. So be careful. The battery you referred in the first post appears very expensive and lacks details needed to determine what it actually is


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## sunworksco (Sep 8, 2008)

Where can I buy NCA battery packs with BMS?


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## major (Apr 4, 2008)

sunworksco said:


> Where can I buy NCA battery packs with BMS?


You get one free with each Tesla Model S.  I don't know where else. Maybe guys on ES would know.


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## snooky (Aug 8, 2013)

You can check Pauls em3EV website..

I believe INR18650-20R are NCA but it's so hard to tell, and come with a BMS in a bike friendly hardcase.


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## major (Apr 4, 2008)

Here is a thread looking at Panasonic NCR-18650A cells which I think are NCA. http://www.diyelectriccar.com/forums/showthread.php/ncr18650a-packs-83923.html


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## sunworksco (Sep 8, 2008)

500 cycle life is really low-life and not a consideration for my application.
Too bad Panasonic and Tesla are monopolizing the long-life cells!


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