larry, it took me about a week I think to stop scorching some cartos. And I went through a brief period (often reported by others, just a day or two for me, then it comes back full force) when all flavors lost all taste to me, so that didn't help.
Now I immediately recognize the loss of taste and the very slight toasty marshmallow undertaste. At first I was opening them up and pulling out batting to test my perception, and some were still way juicy and others were quite toasted. Then I was always right and that was that; a few wasted cartos. (A drawback to the carts with glued on caps.)
It just happens as you get used to them I think, and your tastebuds become more attuned. You won't be vaping until there's a really burnt taste - that's too long.
Turned a friend onto them last night, and at one point said, "That one should be about done, let me taste." It was done.
"I don't taste any difference", he said. He'll get it.
He was absolutely skeptical about the whole thing, a very set in his ways guy, by the way. LOVED it. He'll be ordering the UU kit.
I always charge my batts all night; it's part of my nightly ritual. Others have reassured that it's no problem.
Welcome, and have fun!