I picked up a nitecore i4 and had issues with the first one, replaced it and the second one has some issues. I know that a few other vapers that are local that have the same charger and have had no issues. After getting two duds I am looking at other brands. I have read some reviews for a few other brands. I think I am going to spring for a Efest luc v4 however I was looking for other peoples experience as I have grown a little frustrated.