...Can the blank cartomizers be refilled with the same flavor of e-juice, or do they need to be tossed after one use? Also, I refrigerated my e-juice to preserve it's freshness....Hi Scarlet, congrats on starting your vaping journey...it's gonna be fun!
Regarding lifespan and refilling of cartos, Buzzy gave a good capsule summary, and the particulars and quirks of each brand is part of the learning curve.
I believe the current concensus regarding refrigerating your juices is to not refrigerate but leave in a cool, dark environment. Many juices actually mellow and improve their flavor with age.
Happy vaping to you!