LiitoKala 26650-50A 5000mah 26650 - great first impressions

Nice caps on those cells! can't wait to get mine. But I'm more interested in the HGH - pm me where to buy!

Gearbest 4 for little over $22 incl shipping.

Just got my LiitoKala 26650 from Gearbest and did a 5A discharge test. Here is the discharge curve of the LiitoKala compared with a purple Efest 4200mAh I got from MTN in March. Discharge was done through a 300W Turnigy Reaktor hobby charger and the voltage right at the cell contacts was recorded using a Junsi Powerlogger 6s.

Edit: added pictures


The internal resistances of these two cells are very close based on tailcap measurements in my 3V XHP-70 light and the voltage right after discharge starts in the curves above.

The Efest curve has the distinctive hump around 2000mAh that is very similar to the Vappower 4200mAh cell tested by HJK. This higher voltage hump is nice since it results in increased performance in direct drive setups when the cell is partially charged. Indeed, the Efest curve looks identical to the Vappower curve except it is about 0.2V lower, which could be a result of the age of the cell increasing the IR.

Hello!

Interesting information, EasyB . For some reason the whole graphs are at least somewhat below where I'd expect them to be for 20ish mΩ batteries (barely above 0'1V of drop at 5A).

Well, now that I may continue a bit with this crazy hobbie in a near future, this leads me to invest in further optimizations for my shabby flashlight XHP70 conversion; seeing graphs like that makes me think it may be a hard task keeping the voltage above 7'1-7'2V at the driver's input even before 50% depth of discharge.

Peace & love,

Salvador

I did a crude measurement of the efest 26650 IR a while ago by discharging at 1A, recording the voltage, then increasing the current to something like 8 or 10A, and quickly recording the voltage again. Then the DC IR is delta(V)/delta(I). I estimated 35mOhms. This is really the value of IR we care about, rather than the AC IR that chargers usually measure (I think).

Using this procedure for HKJs data for the vappower cell, I get 31mOhms. He lists the calculated IR as 50mOhms for this cell, so I’m not sure how he calculates it.

http://lygte-info.dk/info/Batteries2012Info%20UK.html

Based on this it looks like he calculates the IR from the protection tests, in which the current is ramped up to see when the protection (if present) kicks in. He basically calculates the slope of the curve between two data points. This is a fine way to calculate the IR. However, if the cell is allowed to discharge for a significant amount of time at each current, it is possible to overestimate the IR. The voltage drops as a result of the increased current (this is the voltage drop we are interested in), but it also drops as a result of the battery being depleted. So if the test is not done quickly, the voltage drop from the battery being depleted is included in the calculation and the IR is overestimated. Based on how much the voltage drops with each successive current ramp, it looks like a significant portion of the cell capacity is used during each current ramp, so I suspect the IR is being overestimated due to this reason. This phenomenon would also cause overestimation of the IR by different amounts for different capacity cells and cells with very different shaped discharge curves.

http://www.aliexpress.com/item/Free-Shipping-2PCS-LOT-Real-Capacity-3-7V-26650-5000mAh-15A-Continuous-Low-Internal-Resistance-Li/32584248563.html?spm

I bought some at here and seems very good quality

Got in my GearBest battery order: 4 LK's, 4 SONY VTC5's, and 2 GA's - total of $47 is simply outstanding. Could have spent that on the VTC5's alone from some other sources.

I did a capacity test on my Opus of 2 of the LK's (LiitoKala) and got:

  • 5420 mAh
  • 5428 mAh

So seems right in line with what others are getting/have posted. Quick test in my FET+1 (ATtiny25/SIR800DP/dedomed XM-L2 U4 1C) based Convoy L2, and got the following measured at the tail on a clamp meter:

  • LK @4.22v: 5.43A
  • BASEN @4.22v: 5.42A

So for internal resistance, seems right in line with the BASEN cells, and also the EFEST 4200's I've measured in the past on the L2. This a somewhat limited test though without testing actual lumens output over time, comparing the cells, so not sure how much it's worth.

Bottom line is having a 5000+ mAh cell with performance at, or around, the best performance on any cell available is pretty amazing. I'll be ordering more...

Thanks Mitko!!

Edit: Has anyone confirmed these sold at FT under the Soshine brand name are the same thing? https://www.fasttech.com/product/3486100

They sure look exactly the same, accept for the cheap name brand printing...

100% same resource

100% same resource

Hmm.

My Opus 2.2 is showing 54 and 50 on the IR quick test with 5130mAh and 5205mAh on the two LiitoKala cells I acquired.

As if I were to trust those cheap electronic devices with regards to precise DC internal resistante readings… :person_facepalming:
Get a decent multimeter capable of at least reading to mV, and a load with precisely known sufficiently low ohmic resistance to induce a noticeable reading delta on the meter. Do your math then (promediating both initial and final no-load voltage readings in order to dismiss any potential inherent variation in it due to the own discharge process).

Cheers :partying_face:

Now this is interesting, used Heters in the S70 and Liitokala in the L6
The L6 got much warmer and was brighter.
Since the Heters have buttons I have to remember which one was placed head side and swap each charging.
The Liitokala have no button so I use a magnet. Before charging I put the magnet on the other one so the swapping is easy and requires no remembering.
Decided to do the same after checking the ano of the inside of the S70 and seeing it is good.
And now the S70 is brighter then the L6 and not just a tad but really obvious brighter. It also gets warmer then before

These Liitokala cellsist provide more power, nice!

OPUS test result for IR is not accurate

Agreed, it has been stated on here several times that the OPUS gives higher than true readings.
However as long as you always use that same charger for analysing you can still get get an idea of how your cells are.

I already got like 16 of those, they all have the same good quality: a bit better than Efest 4200

For me its the best high amp 26650 battery atm: and overall the best too, the price is lovely also

P.S

A tip: orther them from GB - they somehow manage to ship them safely to EU- all my orders came very fast so far, declared as kitchen goods, ” srom stuff”( dunno what that means , a quote) or just el. components

Thank you again for updating information on this battery. I have ordered 8 of them from GB too, but they still are on route.

They seem to be a good battery and very much like my favorite Vappower 4200mAh, but at much lower price

I also got several Vappower 4200mAh before, they perform lesser than Efest 4200, they are like Keeppower 4200 actualy, good battery but nothing like Li 26650, the last one realy shines with out BLF fet DD drivers

This is good news the Vappower 4200mAh are older and very hard to find in the U.S.; I have used the Keeppower and the Shockli 4200mAh’s and found them to be good too.

The Li is a bargain. :slight_smile:

There appears to be a new 26650 champ in the 4200mAh category. Tested by Mooch at the ecig forums:

Excerpt from his test report:

“…This is the first 26650 I’ve tested that acts like an 18650. Its internal resistance is lower than many of the good 18650’s and it held its voltage well. At 30A/100W pulsed it ran approximately 75% longer, and 0.15V-0.20V higher, than the Basen and Brillipower 4500mAh cells down to 3.2V. It doesn’t match the appearance of any other 26650 I have so I don’t know where this cell came from…”