Back in April, I ordered a pair of Samsung 25R and Sony VTC5A batteries, and have been using them daily in my Cuboid and eVic Primo 2.0. I've been keeping track of their accumulated charge/discharge cycles, and both have just hit 250 cycles. Most of the time they were charged when discharged to 3.1 - 3.2 volts (when I would start getting a weak battery warning). Occasionally they were charged earlier, but never before being discharged to 3.5 volts. I am seriously impressed with how they are holding up, especially the VTC5A's. When new, both would provide between 800–1000 seconds of vaping at an average wattage of around 70 W. After 250 cycles, the 25R's are giving me 700–900 seconds, and the VTC5A's are still giving 800–950 seconds.