So you are in off topic without a device name, or even device type.
I guess you had what many around here would know as a mintyboost but had a cheap and nasty one. If I wanted something like this I would probably build my own (it is a battery holder, some form of voltage regulation, a socket and a switch). Not sure what people are opting for if they just want to buy something though.
I personally use the Panasonic NCR18650B in my vaporizer and flashlights. Nitecore also always makes solid, reputable batteries and chargers.
I have less recommendation of what to buy and more what not to buy. The people I talk to mainly say to keep away from brands with the word "fire" in the name. Surefire, Trustfire, Ultrafire. Same goes for chargers.