Kdest 18650 3500mAh 30A Battery
To avoid any ambiguity with eGo-type "batteries," I employ the term "cell" in this context to denote a single 18350, 18650, 26650, and so forth.
Although the test results provide concrete data, the conclusions and recommendations I draw from these tests are purely my subjective viewpoint based on my established criteria. In addition, is crucial to conduct thorough research on any cell you are considering before purchasing.
Attempting to test cells at their limits is dangerous and should never be undertaken by individuals who have not extensively studied the associated hazards and effective risk mitigation measures.
If the cell bears only one current rating or states "max discharging current," I must assume that the company claims the cell can be discharged at that specific current level, regardless of the discharge method employed.
18650 li-lon battery Key Point
This Kdest product, like the best 18650 batteries, is a rebranded and exaggeratedly rated 10A 3400mAh cell. When operated at its continuous rating of 15A, it reached a temperature close to the boiling point of water. The so-called "pulse" rating of 40A is unreasonably high and would drop the voltage to impractically low levels. These Kdest cells exhibited identical performance and appearance to the LG MJ1.
Kdest has imprinted "MADE IN KDEST" on the metal casing, which is noteworthy considering that this is a rebranded LG cell.
The 18650 ratings table has been updated to include this particular cell. The two compartments were acquired directly from Kdest (Kdest) for testing purposes.
Results of Pulse-Current Testing
Pulse testing was not conducted since this is a rebranded MJ1 cell. The test results for the original cell are available here: LG MJ1 10A 3400mAh 18650 Bench Retest Results... a commendable 10A battery.
18650 li-ion Battery Observations
At a continuous current of 5A, it attained an approximate capacity of 3100mAh, like the Efest 20700 3100mAh. This represents the average performance for a 3400mAh cell with high internal resistance operating at 5A, leading me to rate it at 3400mAh.
At a continuous current of 10A, the temperature rose to 69°C. This figure falls a few degrees below the average temperature of a cell operating at its constant discharge rating (CDR), indicating that we might be operating slightly below its actual rating.
At the specified continuous rating of 15A, the temperature soared to 96°C. This value significantly exceeds the average temperature of a cell operating at its CDR, indicating that we are working well above its actual rating. The voltage sag observed is substantial and suggests its accurate rating is around 10A.
At a continuous current of 20A, the cell proved to be practically useless.
I am setting a CDR of 10A for this cell. While operating any cell near its maximum rated current level causes damage, I anticipate good cycle life at a continuous current of 10A.