There have been few posts over here and at CPF that some Opis BT C3100 users found that their chargers overstated the battery capacity when the run discharge test, i.e. the capacity of their batteries (especially 18650) as shown on their Opus can be 100-200 mAh higher than the official rated capacity.
I have never encountered this problem on my Opus, just that this issue are mentioned by some members at both forums
I am performing another charge/discharge test just to see if there is any difference in capacity after a second charge & will post the results later today.
Second charge/discharge cycle finished.
Cell 1, IR during discharge 23, capacity 5114
Cell 2. IR during discharge 18, capacity 5190
So fractionally better than the first test results but still within a few ma”s & the cells seem pretty well matched 
Nice numbers, indeed.
Now, if those IR values are to be believed, that would mean these cells should handle a continuous 20A discharge rate with ease (within a ≈10W thermal envelope). 
Grreat! 
Cheers ^:)
Darn, I only bought one to play with a week ago. Any left? I know GB will say they have them when in fact they don't. Well, against my better judgement I went ahead and ordered 4 more. I don't expect to see them in any less than 60 days, maybe longer.
What are you discharging them to? 3 volts?
I have another pair coming from another supplier so we will see how they test compared to my first 2.
Might show if there is continuity with these cells 
My other pair of cells from the other supplier have just arrived
Checked the voltage & both showed 3.79v, exactly the same as the first pair :+1:
I have just started a charge cycle & will report back with charge & discharge results when finished
Just received 4 pcs of Liitokala 26650 yesterday. Voltage around 3.82 V.
I will do capacity tests on 2 of them in the next days. Tests will be on 1A, 3A and 5A. 7A test is possible on request.
The more current, the better
Thanks for all the info! What sellers have you bought them from? The first and second pair?
Has to follow this thread. Got 4 from the Ali seller and 4 from Gearbest. Will take weeks before I have them I’m sure off.
Can these be used in series or they are full flat tops?
They can but be advised all: those batteries are kinda not exacly 26mm but like an idea thicker, they barely fit into S70 for instance
As IMR/INR they dont perform well in series with buck drivers- i would reccoment Efest 5200 or Soshine 5500 in this case
First pair were from Aliexpress, second pair from GearBest.
Gearbest”s were much better packed
They are on discharge now
Now this is something I didn’t know… Can you explain it further? Is it because of less voltage sag?
They are full flat tops. Can`t use them in series. I have 4 from GB and they came in good condition at each 3,82 Volts. My discharge test on opus-bt at 1Ah shows 5445mAh, 5367mAh, 5289mAh and 5398mAh in the first cycle. Internal resistance test with opus-bt all four under 30.
Robert
Mine fit in my S70 fine diameter wise, you can even rattle them slightly so they are not a tight fit at all ?
Could you please elaborate on that?
To me, what you said there just does not make sense at all. I am to get a couple of batteries for an XHP70 custom build, powered by a buck driver I am going to optimize. As I see it, a couple of these seems wonderfully adequate: at 4'8A maximum driving current, the Vdrop caused by an in-series couple of these will always be, at most, 0'3V, which allows the driver I am going to use (unmodded) to stay in regulation down to 7'2V or about 7'5V no load; my “optimizations” (much bigger & very low ESR inductor) should allow me to enjoy a driver overhead reduction of around 0'2V.
Cheers ^:)