There's a couple of the ultraslim mods out there that I like for being out and about. If I recall correctly, both use the 10440 batteries. Assuming the use of standard atomizers or cartomizers (as opposed to LR), what kind of battery life do you get out of these? Living in the middle of nowhere, when I venture out, it's usually around a 3-4 hour trip and just wondered if I'd need to be carrying several batteries around with me.