I wanted to test the vapcel h16 18350 5a 1600mAh and the keeppower 5a 1600mAh batteries that I think are the same. I picked a light that I knew would try to draw more than 5 amps on turbo. I picked 6 18650 and 5 18350 batteries. All were between 4.01 and 4.06 volts. That is where I normally store them in battery boxes or in lights. Battery temperatures were probably between 60 and 64° f. Some have been used in recent months and some might not have been used or touched in one year.
Setup.
I used the armytek wizard pro nichia 3000k from killzone.
I had it head standing in a large pill bottle with water above the fins. I wanted to get through all the batteries in a reasonable time without heat or step down becoming an issue. I did change the water twice when it started getting warm but I didn’t document those points. I planned on measuring starting amps and 30 second amps but ended up running each battery for at least a full minute. Some batteries also have a 40 sec measurement. I had a mechanics extendable magnet ready to retrieve batteries so I didn’t have to take the light out of the water. I estimate the rest time was at least 90 seconds to document numbers, change batteries, reset the stopwatch, get the wire ready, check zero ect.
I used about 18 inches of # 14 tinned copper stranded wire. Not fine strand. UT210E.
The scorecard might be a little confusing there were 2 vapcel (V) 5 amp labeled 1 and 2.
3 keeppower (KP) batteries. 2 were 10 amp and one 5 amp.
The last six lines were all the same battery with about a one minute rest between tests. And then two more tests with that same battery after I charged it to nearly full.
You’ll see I had a problem the first time I ran that #1V. I think one of the strands of the wire might have been touching the wall but I’m not sure.
I found it interesting that most but not all peaked in amps somewhere around the 30 second mark. I suspect it is in part due to the batteries warming up internally. Although it could be something going on in the driver. Most got fairly stable between 40 seconds and 1 minute. But I didn’t run many of them much beyond 1 minute.
I may do this again with another light. I think I’ll use a larger container with more water and maybe even use ice water just to make sure I get to a full minute without the driver slowing things down due to heat. Or at least whatever time the light normally steps down at.
Some of these batteries are one to two years old but some of the 18650s might be almost 5 years old.
The specs on that wizard are for the 4500k not the 3000k that I have.
It is not the driver that is responsible for Amps jump after 30 sec, I experienced same with some brands of alkaline AA, after about 30 sec, they were able to supply 2x the current, while others brands did not. Believe it or not duracel optimum AA is able to supply 4A. Not for long, but still, 4A from alkaline AA is impressive.
So what are the conclusions?
- Temperatures - ar 5A actualy that much warmer?
- Does runtimes improve on 1600mah vs standard 1100mah?
- How about brightness?
I tested how much current several different brands li ion 1.5v rechargable can supply, for the test I used convoy t4, 2AA, I tested tailcap current. But after testing li ions, I decided to see how alkaline comapre.
My conclusion was, li ion can only put out 2A max and not even all brands, some would not go past 1.3A. those were no name cells from ebay, alkaline were ace hardware brand, energizer and duracel optimum, which started from 2A but after 30 or so seconds, jumped to 4A. others alkaline did not do that. I did not test brightness or temp, it was not the goal of the test, not sure where 1600 and 1100 numbers came from.
Sorry, that was suposed to be reply for @Oli and that 18350 batteries 
A few of my Armytek loghts do exhibit that ramp up in Turbo, wth output peaking at 30-40 sec affrt turn on..