My vaping style, where I have it personally, it a cartomizer a day now.
So, I know that during the day, I smoke so much....when I get home, I add a few drops, and that extends the life of my cart for the rest of the day. I refill it with more before bed, and in the morning, I am set.
It just takes practice.
Kc says it best though....at least his way, you know for sure.
Yes and if you're only puttin in a couple of drops..battery end can work..but if you dissect a cartomizer you discover what is wrong with full refills via battery end.
Basically there's a slotted centerpost at the battery end that you drip into..what you don't see is that there is a long metal tube attached to it..which then feeds into a flame proof silicone wrapped tube of some woven material.
Air flows through that center contact..through the metal tube past the atty (located beside the flame proof silicone reinforced tube) and then out to you for you to enjoy.
Wrapped around this surprisingly complex assembly is the batting..where the juice is supposed to be..where it's found, wicked up and vaporized by the atty coil.
Basically, when you drip into the battery end, the drops have to go in the metal tube, through the woven/silicone reinforced wicking tube, out to the cartomizer open area..then bounce off the silicone washer and turn an about face and retreat to the batting.
This is why you hear about people dripping and "rolling" the cartomizer when filling it via the battery hole...they may not realize why they have to roll it...but basically theyre tryin to get that errant juice home to the batting.
On a side note, many cartomizers pretend to be flooded when theyre empty!..no kidding!
when you refill a cartomizer, always ensure you have the little .... plug in...if you do not..the juice goes in the batting a little ways then heads right for that battery hole.
The little .... plug is designed to fill that metal tube so the juice has no choice but to go into the batting...and if it still refuses (yes this can happen with some thicker juices and particularly with VG and VG mixes) you end up shaking it down to get it in there.
A brand new dry carto will rarely do this..but one that's been used and refilled several times develops some kind of "buildup"...like the waxy buildup my pledge puts on all of my furniture LOL...but seriously..it resists fluid and requires shaking down...some juices do this some do not.
Whenever you *think* you have a flooded cartomizer...take it off the battery, reinstall the buttplug, and shake the bejeezus out of it (towards the battery end) to force the juice down into the lower batting...you'll find this resolves it 90% of the time..the cartomizer wasn't actually flooded after all!..the juice was just lost on it way to the batting.