The two cells are very well matched and as usual I test them a bit above specifications. They handled 20A fine, but did not like 30A continuous, it blew a fuse inside both cells, preventing me from doing the rest of the tests.
AT 20A they get rather hot, I measured about 78°C.
At 30A they reached 86°C before the fuse blew.
Conclusion
The performance of these cells looks very good and I will look on it as an advantage that they blew a fuse when overloaded (Instead of blowing up).
For vapers that want to use 30A, this fuse is no problem, I draw 30A for about 8 minutes continuous before it blew.
Notes and links
The battery was supplied by shockli.com for review.
This manufacturer also most likely makes the cell in the Liitokala 26650.
So it was not a protection circuit that blew, correct? Do you think it was something like a current interrupt device (CID) tripping, from getting too hot and internal pressure increasing?
It is part of the safety inside the can, i.e. you cannot get to it without destroying the cell.
The fuse is there to prevent the cell from doing something nasty (like explode).
Excellent review. Like the fuse for safety (of which the cut off point is way higher than general flashlight use). Just a shame that the cell is so wide, almost a 27650.
Average internal resistance looks slightly below 25mΩ, just a gnat's ass higher than that of a LiitoKala 26650-50A. Definitively an improvement in energy density, with an actual power delivery rating. Verrry good!
About the fuse, a bit sensitive I'd say. Temperature monitoring definitively recommended/advisable.
Cheers ^:)
Originally posted on Mon, 04/24/2017 - 01:33; IR estimation fixed, content added and make upped.
The shockli would perform better over time because of its higher capacity, not because of a lower IR. At a given resting voltage, like fully charged at 4.2V for example, the cell with the lower IR will provide more current in a direct drive situation, but a cell with a lower capacity will drop its resting voltage quicker over time.
It seems like a compromise between IR and capacity oftentimes. The VTC5A would give more amps at start than this shockli, but obviously the capacity is in a different ballpark and would not be as suitable in a high power light.
Here's the 5A comparison below. So accept for the first 0.25 discharge, the Shockli performs better - the blue line is clearly well above the red line. I though it should produce higher amps in a DD/FET mod, accept for the first 250 mAh. Am I reading this right? Does that first small advantage for the LK mean it will have a lower internal resistance?
The internal resistance is measure at 15A (if the cell can deliver that), but higher voltage at the desired current is always a better metric to look at.
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