Test/review of LiitoKala INR26650-50A 5000mAh (Black)

Standard Discharging Circuit: 0.2C A
Fast Discharging Current: 0.5C A
Max Discharging Current: 2C A
Max. Short Peak Discharge CC: 15A

What could these cells be? The specifications look close to that of Samsung 50E or LG M50, but looks slightly different to both. Maybe some high capacity Lishen 21700?

2C Max - does this mean 2 Amps continuous? That would be too low even for single emitter lights…

C means capacity, this means a 5000mAh (5Ah) battery would be 10A with a 2C rating.

This is new to me, why not to put there just 10 Amps then? Would be interested in learning more about this C rating.

It is not a new system, the advantage is that many batteries sizes/capacities have the same charge/discharge limits when using C rating as long as they use the same chemistry.
Once it was very common to see 2C discharge and 0.5C charge rate for LiIon and it is still a good and fairly safe guess if the only specification you have is capacity.

Disappointing! these are clearly not the same cells Petr J got

Wow that sucks. I guess i was lucky with the 50A 26650’s, both were measured at over 5600 mAh. The lottery with non-japanese made 21700s is pretty frustrating.

To answer your earlier question, I think you removed it, some manufacturers measure capacity from 2.5v to 4.2v. I was hoping HKJ would answer you as he’s the resident expert an batteries.

Since he didn’t, I looked up a couple of data sheets. Here is a quote from the Sanyo 3400mah GA data sheet.

“Capacity is measured by the discharge at 0.67A until end voltage of 2.5V after fully charged at 25℃ as described in the specification.”

Here is from a Samsung 40T.
“Standard discharge capacity is the initial discharge capacity of the cell, which is measured with discharge current of 800mA(0.2C) with 2.5V cut-off at 23℃ within 1hour after the Standard charge.”

So this quick sampling shows they go down to 2.5 volts. I think HKJ might only go down to 2.8, I’m not sure. I don’t think there’s much difference between 2.5v and 2.8v.

If you only let it discharge down to 3.4v then there is a bit more capacity left. Looking at a random 5000mah 21700, the LG M50, I see HKJ measures about 4,000mah at 3.41v at 0.5A discharge. As it goes down to 2.8 it gains another 800mah or so. Same for the Samsung 50E and 48G. They all gain another 700-800 mah from 4.1v to 2.8v. So I would guess your cells would read about 4700-4800mah if you discharged them further.

I was looking at Petr J’s sample he has 4800mah @ 3.42v at the same 3.42v mine have only reached 3946mah when i totally drained them till the Flashlight shut off and recharged them i got 4100mah

I’d say that is fairly conclusive?

( I got stitched )

Which 26650 do you mean?
Capacity is not everything, you still want it to pull some good amperage as well.

Yeah, a lot of rewraps going on. I’ve had good luck with the Sofirn black and gold 4000mah 21700 and I hear the Lishen/Liitokala 4000mah is good. Other than that, I don’t know. I try to use Samsung or other big name when possible.

Not really. These battery charger testers are not that accurate, but it’s very likely they are not the same cell. If Petr J discharged down to 2.8, I wonder how much capacity it would show? 5700mah? Seems way too high. I would ignore his results and measure yours to 2.8v. Maybe you can use 1A to speed up the process? If you get 4800mah or so, that’s not so bad.

If Petr J chargers are reading close to accurate, then those cells are quite amazing. The highest capacity 21700 I have ever seen was about 5200mah measured by the manufacturer. I forget the brand. If someone is making a cheap 21700 with 5700mah capacity that would be big news. Does such a thing really exist?

when i totally drained them till the Flashlight shut off and recharged them i got 4100mah, but i will fully recharge them and run fast test down to 2.8v to see what happens :slight_smile:

The 12x 26650 lii-50a’s have all scored +5000mah without going to super low voltage, so i am still pretty happy, i only grabbed a couple of these yellow 21700 to see if they were any good.

Batteries are rated for different discharge voltage.
The first LiIon was usually 3.0V, some 2.75V.
With more modern chemistries it is usually 2.5V or a few times 2V

When I started doing my test 3V and 2.75V was very common and I decided on 2.8V, mostly because it was the default on the iCharger I used for my first battery tests.

How much capacity you can get below 3V depends on the actual LiIon chemistry and the current, but it is usually not much.

Like Barkuti said, you might have some good Lishen 4000mah cells with a 5000mah wrapper on them. It is not what you ordered so you can complain and maybe get a partial refund.

I can’t remember, did you and Petr J buy from the same store?

yes same store… same link in fact but different times i think he purchased his a while before me.

liitokala Official Store (Store No. 217753)

https://www.aliexpress.com/item/32845153871.html

Maybe like Barkuti said they just made a mistake at the factory and wrapped the wrong cells… they do list this same 21700 in 4000mah version as well

Time to make NOR tests for all the Lii-50E cells you received, The_Fat_Controller. Example:

When you select 300 or 500mA charge current the corresponding discharge current is ≈250mA. When you select 700 or 1000mA charge current, the discharge current is ≈500mA. Big difference which speed things up.

Are those real Sony VTC6 in your picture? Or are they “LiitoKala VTC6”? Been thinking about ordering these or 30Q’s, but preferably original ones.

ok, dragged to it’s absolute last. Ignore 2.95v END is flashing and the cell is recovering voltage the test finished at 2.8V

Better than i expected.

Cool, that’s more than I predicted. It still seems like a different cell than Petr J got, but not bad overall. About what you would expect from a 5000mah cell. So it’s not the 4000mah with the wrong wrapper on it.