Shockli IMR26650 5500mAh (Black) 2017
Nominal voltage: 3.7V
Nominal capacity: 5500mAh
Charge voltage: 4.20V +/-0.5V
Standard charge current: 0.5A
Maximum Charge current: 2A
Maximum continuous discharge: 20A
Maximum pulse discharge: 30A
A high current and high capacity 26650 cell.
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.
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.
How is the test done and how to read the charts
How is a protected LiIon battery constructed
More about button top and flat top batteries
Compare to 18650 and other batteries
Compare to 26650 and other batteries
Looks like a great cell, possibly the highest capacity 26650 cell you’ve tested. It looks like it’s the 5500mAh version from PLB:
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?
Yes, but the cell do not look like it vented, the top do still look pristine (usual there will be some traces when the cell vent).
Nice review! Looks like a best performer, all around. For 26650's, the iJoy 26650 4200 might have to take 2nd place now, accept if running at 30A.
I'd like to buy a couple. Just emailed Shockli - can't find a retailer.
What happens after the fuse is blown? Is the battery usable?
No, it is dead. It is not a protection circuit or PTC that can recover.
Hi HKJ, the coolest tester in the world
Do you know where that fuse is located?
Is it possible to the throw it away and use the cell “unfused”?
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).
Wondering if they can send you replacements - love to see the internal resistance result. I'd suspect it's below 0.4 from your discharge curves.
That’s what I mean - pry it open, short the fuse and use it again. But not at 30 amps
I doubt you can put it together again if you pry it open. The cell may also take damage from the air.
Oh, it’s somewhere inside the chemistry. Now I get you. Thanks.
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.
Comparing the discharge curves to the liitokala 26650, the IR looks just a bit higher for this shockli cell.
It is a fat cell, like the liitokala cell. Makes sense if they are from the same manufacturer.
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.
Originally posted on Mon, 04/24/2017 - 01:33; IR estimation fixed, content added and make upped.
Maybe I don't understand it. In the comparator looking at 3A to 10A, the LK looks worse in 98% of the discharge curve.
The Shockli has a higher V for just about the entire discharge. I thought that was better?
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.
OK, thanks! Didn't realize that. Still at 15A, the initial drop is steeper than the LK, but maintains a higher voltage after that first 250 mAh.