Also as far as batteries go I wouldn't buy a battery from Ebay. I have in the past with the "Authentic" written in the heading and below stating they are an authorized seller for X brand just to find out once I got them they where not Authentic at all. There are places like
IMR Batteries or
Liion Wholesale that offer great prices on trusted batteries (LG, Samsung and Sony).
Even with these batteries you have to make sure you get one that has an amp rating that is safe with the ohm rating you intend to use with the mech. mod, this is where
ohm's law calculator comes in. In order to know the ohm's of your coil you have to have an
ohm reading device to measure the resistance and also let you know if there are any shorts which would make it unsafe to use.
As far as clones go you may get a good one or may not???? I have a brass Cartel clone by Cigreen and it is fantastic and hits like a train so I wanted a Stainless version of it also and decided to buy one from Ebay (no name clone) the thing wouldn't even fire when I first got it since they had made it so poorly and even after I fixed the part they screwed up the switch on the bottom is so cheaply made the thing hits like a girl, it's new job is to sit there with one of my RDA's on it as a holder.