If want to kick the analog (old cigs), you might want to use little stronger nic content (18mg) for a few days and change the cart whenever it loses "throat hit" (about 3-4 cig equivalent). It worked for me.
I think refilling carts is better than prefilled carts, because they are much cheaper and you can put any flavor liquid you want. To do this, I suggest that you save all used carts (including the white gel cap) and, if needed, buy some more empty carts from PS.
If you look inside the cart, you will see the inner cart. You need to put the liquid in this tiny inner cart. Some people suggest that you pop the inner cart out to fill it. But I, myself, find it easier to just use a syringe (which you can purchase from PS and other online e-cig vendors).
1) Put a syringe into the liquid and draw a couple of milliliters (ml).
2) Put the syringe, the niddle, into the cart, and push the niddle into the inner cart, the white sponge-like stuffing. It is better to aim at the side of this sponge than at the middle, just be sure that the niddle is inside the inner cart.
3) Push your niddle down to the bottom of the inner cart (kind of push aside the stuffing).
4) IMPORTANT. Slowly inject little less than 0.3 ml, say .25 ml. If you put more than that, it will overflow.
5) Put the white gel cap back on. You are done.
I usually refill 20-30 at a time, refill the syringe as needed, any leftover when done, dump back into the bottle.
1 ml = 20 drops. So you are putting about 6 drops into each cart. On average 15 puffs per analog. You get about 15 puffs from .1 ml or 2 drops. So, that's why you get about 3 decent analog equivalent from 1 cart.
You can get e-liquid at about less than $1 /ml. 30ml costs less than $30. So, you are refilling a cart at about 30 cents per cart.
Nicotine Content. At first, you should use a high concentration than you need just to make sure you get enough to stay away analogs. But the number works out this way:
When they say 18mg, that is 18 mg of nicotine per ml. People take in about 1 mg of nicotine from analog (full, light, ultralight do not vary a lot).
So, if you want the "equivalent" amount of nic, 2 drops or .1 ml should have 1 mg. Around 10mg e-liquid would do it.
However, you could also dilute the e-liquid. Call around local pharmacies for Propylene Gylcol. I got mine from Target pharmacy at $12.99 for 473 ml or 1 pint. Works out as about 3 cent per ml.
Get yourself 18 mg e-liquid, put 1 ml into a small container and add 1 ml of PG into the same container, close the lid and shake it up like a martinini. Now you have 9 mg e-liquid at 52 cent / ml, less than 18 cents to refill your cart.
If you want to do this, I suggest you try small amount first. Diluting cuts the flavor as well--which turns out to be a no big deal for me. In addition, if you look at DIY forum here, you will see many interesting flavors you can add youself.
