I got these suckers cheap from liionwholesale and they will keep a smok G-Priv and sense blazer ceramic coil setup at 150W for the night. Make sure to watch your batteries and never drop em. Remember the hoopla surround VTC4s, the many fakes and stuff? That's history. LG came through with HB6 30-32amp 1,500mAH beasts and any heavy vaper should own at least a pair of VTC5As and HB4s. Sometimes HB6s are overkill for many users but HB4s dont rip upon inserting and removing overtime.