What 18650 batteries for MECH MODs?

There is a lot of batteries 18650 in the market. Cheaper, more expensive, originals, clones, etc... But which one is THE BEST for my mech mod?? 

During last 2 years I've been testing it in various ways. Finally I found that the best way (as close as possible to reality, actually worse then reality :-) ) is continuous load test. Preferably at quite low "coil" resistance, lets say 0.5 ohm. So, I constructed test setup described here and started to test... Below you can see the results for 18650 batts.

WARNING - today I rewrite this post, mainly to show the usefull capacity of ALL tested batts in one combined diagram at the beginning. 

Of course voltage and temperature diagrams would be unreadable in one picture, so I divided them.

14-04-2016 UPDATE - COMBINED CHART

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Let's start from the batts:

---------------  18650 batts - first batch  ---------------

1. AW IMR clone.
2. Panasonic NCR18650PF.
3. Samsung INR18650-15M.
4. Sony US18650V3.
5. Panasonic CGR18650KA.
6. Efest Purple 2500 mAh.
7. Samsung INR18650-29E.
8. Sony US18650VTC4.

Most of batteries were after 6-10 charging cycles.

---------------  18650 batts - second batch  ---------------

1. Keeppower 3200 (the "old" one).
2. MNKE.

3. AW IMR genuine.

4. Sony VTC5.

5. Efest Purple 3100 mAh.

All batteries were after 10-15 charging cycles.

---------------  18650 batts - third batch  ---------------

1. Keeppower 2500.

2. Keeppower 2900.

3. Keeppower 3200.

4. AW IMR genuine (the "new" one).

5. Efest Purple 2100.

All batteries were after 3-7 charging cycles.

---------------  18650 batts - fourth batch  ---------------

1. AWT 2000.

2. AWT 2500.

3. AWT 2600.

All batteries were after 3 charging cycles.

---------------  18650 batts - fifth batch  ---------------

From left:
* LG DBHM,
* LG DBHE,
* Sony VTC5,
* Samsung 25R (at last),
* Efest 3100. 

As you can see there are two batts which have already been tested: Sony VTC5 and Efest 3100. I repeated these tests to see if the batts bought after half a year keep the quality. And what turned out? If we look at diagrams below:

We can see that the waveforms are NEARLY IDENTICAL - that's VERY GOOD - manufacturers maintain quality.

So in useful capacity diagram I won't show the results of these two batteries because they are almost same.

The RESULTS

TEMPERATURE

Having the voltage level during whole test and knowing the load resistance we can easily calculate the useful capacity of tested batteries. I emphasize the useful word because it is capacity calculated exactly for the conditions described in the test: for battery discharging from 4.2V to 3.3V at 0.5 Ohm load. In a different measurement methodology the total capacity will differ from this, BUT in my opinion presented methodology is the best from point of view the users of mech mods!