Yocan FLAT series batteries are attractive and have all of the basic functions you need. The batteries are also quite affordable.
Yocan Stix Plus Battery Review
I think this was the best battery brand Iâ€™ve used for simply that reason. Great design, Great options. Great overall.
Yocan Lux is one of the better 510-threaded cartridge batteries as it is discreetly portable, extremely durable, and convenient for travel
The Yocan UNI Pro is a versatile and great all-in-one battery for someone that doesn't want to carry multiple batteries.