18650 Cell choice: Max Constant Current 1/12th of Capacity?

Hello, (posted the same question on endless-sphere also)

I am planning to assemble a Solar Battery from New 18650 cells.
Panasonic, Sonyo or LG seem to be the leading, verifiable brands.

When I ask for quotes I am bombarded with all the newest High Discharge Cells.

Unlike the Majority of requirements for Cars, Bikes and lights,
my requirement is for a Max Constant Current <= 1/12th of the Cell Capacity.

So these are some Lower Discharge types I have stumbled upon,
or followed up after suggestion.

LG INR18650F1L(Rated 3350mAh) (1.5C Max 4.875A)

*PANAS0NIC NCR18650BE (Rated 3200mAh) (Typical 3180mAh) (1.1C Max 3.63A)
*PANAS0NIC NCR18650G(Rated 3400mAh) (Typical 3550mAh) (1.3C Max 4.87A)
*PANAS0NIC NCR18650 (Rated 2700mAh) (Typical 2900mAh) (2C Max 5.8A)
*PANAS0NIC NCR18650D (Rated 2700mAh) (Typical 2550mAh) (2C Max 5.1A)
*PANAS0NIC NCR18650F (Rated 2700mAh) (Typical 2900mAh) (2C Max 5.8A)
*PANAS0NIC NCR18650A (Rated 2900mAh) (Typical 3070mAh) (2C Max 6.14A)
*PANAS0NIC NCR18650B (Rated 3200mAh) (Typical 3350mAh) (2C Max 6.7A)
*PANAS0NIC NCR18650BF (Rated 3200mAh) (Typical 3350mAh) (2C Max 6.7A)
*PANAS0NIC NCR18650E (Rated 2100mAh) (Typical 2250mAh) (3C Max 6.75A)
*PANAS0NIC NCR18650BL . . . . . . . . . . . . . . (Typical 3350mAh) (2C Max 7A)

Looking for Common Cells that might be cheap for +500 and +1000 pieces.
Any suggestions for other Commonly Available, High Quality Cells that might be Suitable for Lower Continuous Current?


i would look for cells with the highest cycle life.

Thanks for input.

I understand why looking at cycle life is a good idea!

After looking at the specifications of quite a few 18650 Data Sheets, the top brands are very similar.
The way I see this is the older Batteries are constantly becoming cheaper as superseded.
Also the Performance of New Batteries is increasing.

With the majority of uses of 18650 cells the Amperage and cycle life per kg is the driving factor, in my case the only factor is cost!

My point is that the Battery I make today from cells could be replaced with better Battery Cells at half the price in a matter of years.
When I do all the Math taking the discounted price of Brand name superseded cells into consideration the cycle life is less relevant.
The resulting Battery is still going to last long enough.

The other factor is the risk with Mark1 battery costing $3000 as opposed to $1500.

I am not arguing that cycle life is not very important, just not so much for my first Battery and minimizing the financial risk!

At the end of process with quotes from suppliers, I will know what cell is the best value for my application now.
With plans to Re-build the Battery with the next price break opportunity in the future.

My only question is which 18650 for <= C1 Discharge are more common with good price breaks, what I am finding is some older Cells stack up, like: LG INR18650F1L (Rated 3350mAh) (1.5C Max 4.875A) and some Panasonic Cells.

Yet to look at Samsung:
Samsung ICR18650-26FM (Rated 2600mAh) (Max 5.2A)
Samsung ICR18650-26H (Rated 2600mAh) (Max 5.2A)
Samsung ICR18650-28 (Rated 2800mAh) (Max 5.6A)
Samsung INR18650-29E (Rated 2850mAh) (Max 5.7A)
Samsung ICR18650-30B (Rated 3000mAh) (Max 10A)
Samsung ICR18650-32A (Rated 3200mAh) (Max 6.4A)
Samsung ICR18650-35E (Rated 3500mAh) (Max 10.5A)

If all you want is slow drain for an off grid setup, go with the NCR18650B, they are probably one of the cheapest LITHIUM options. You should be able to get these for around USD300 a KW (80 cells) if you shop around. There is a lot of work to turn this into a usable battery.

But IMO, as much as I love lithium technology, for off grid solar “second hand” Lead-acid is still a great idea. Big companies change 3 year old batteries that have been on constant charge on critical systems even if they are perfect. Lead likes to be kept charged so you should get 5-7 years more out of these batteries. Then they are fully recyclable at the end of life in which you get paid.

I will give a real life example. I have a mate who I set up off grid, was going to be close to AUD 10,000 for a 14kw usable powerwall. I found some 3 yo great condition lead acid batterys for AUD 1500 with 20kw of power. Using the 50% drain rate he will have 10kw usable. At current rates they batterys can be recycled for AUD 300. So for AUD1200 he has 10kw of usable power (of which he never gets close to using)

Ummmm, for solar, y’sure you really don’t want LFP (LiFePO4) cells?

They make ’em in big car-battery sizes, too.

They’re also much less sensitive to overcharging.

Thank you for your thoughts Lightbringer,
I have not priced LiFePO4 cells, have a particular part number in mind?

Very open to ideas, one thing I have found is many good options in US have not got the market saturation pricing in AU.
Like Forklift Batteries, Golf cart or Electric Cars. I have not found local supplier for cells that can match a months bargaining with Chinese Sellers and half the products value in shipping, so be it in AU.

I am very open to any ideas, if you can suggest anything to check out.


Hi Mud Muncher,

Have to double check the quote but around $2.50 AUD for NCR18650B x1000 before freight.
I have received some better offers on other part numbers, but still a work in progress.

The NCR18650BE and LG INR18650F1L are competitively priced for the application but could still come second to common lead acid.
This whole process started by looking for an alternative to Lead Acid and I have looked at pretty much everything that is available in Australia and Lithium Solar Batteries from China.

I am in small town in Western NSW, we understand freight being fruit and vegetable producers.
Adelaide is our lowest cost with a Local transport firm but for the right price it is not going to matter.

Can you help me source 400Ah of 12v Lead Acid, 48v 100A Bank of Usable Storage?
Let me know if you have any suggestions to kick of the search.


I have sent you a PM regarding this.

Not in the slightest. All I know is that they come that big precisely for solar apps (and RVs and the like). They’re way more forgiving of abuse than Li-ion, and have a very flat discharge curve, just like NiCd. Cycle-life is also lots lots more than Li-ion, if I’m not mistaken. I think they also have LFP replacements for car batteries, but that sounds more like a specialty niche, not something suitable for quantity-pricing.

If you can get those batteries, they’re great in that they’ve geared for deeper discharge than regular car batteries, which are happiest when kept fully charged.

Look here

80 26650 LiFePo batteries with 5000mAh for 120$, sometimes even reduced to 100$
that is 3666mAh per USD

there is no cheaper and more safe battery for your application

dont believe the rating on that cell.
we just got lico with 5.5 ah.
and thats an old cell 9th week of 2013

Hi Snakebite,

If I understand you correctly.
You are saying “Tenergy LiFePO4 32650 3.2V 5500mAh Rechargeable Batteries 5.5Ah”
were made 9th week of 2013 and do not hold 5.5Ah as stated?

Have you got links to tests, or aware of the true specifications for these cells.

Also, what are these lico 5.5 ah you got?
Can you share what you purchased and who supplies it?


What Snake bite is pointing out is that the cell pictured clearly shows 0913 as date of manufacture so it is nearly 3.5 years old.

I dont think that the cells are that old its just a product picture

Those are 32650 cells so 5Ah sounds legit

Thanks Ian, I just wondered if the significance was a particular event in production.
I had not looked at the picture, cheers.

Could be Lex.
My only concern is the lack of information for this particular cell.

Google is not helping much, any user testing out there?

I logged in to Ebay and checked it out,
Item location: Leander, Texas, United States,
doesn’t ship to Australia. (Shipping from US is not viable in any case!)

Tenergy LiFePO4 32650 are not available through Alibaba!

There are Many other LiFePO4 32650 on Alibaba, the question is which manufacture has quality cells.
Also looking at 4x 12V 100Ah lithium iron phosphate battery,
or 17x 3.2V 100Ah lithium iron phosphate battery,
In order to make up 48v 100A!

Any idea of brands or what to look at?