Fish, the contacts between battery and atomizer might need cleaning. Take a tissue, fold it a couple of times. Then fold it over the battery-end or atomizer-end depending what kind of cig you have (copper screwing-part of it) and hold tissue firmly while turning the part around with your other hand.
Then also clean out the threads in the atomizer or battery (depending on cig-kind; mean the part that is hollow) (other half of contact with battery) as well as you can (I push part of the tissue into the shallow hole there; then turn the tissue around a lot while also pressing it with a nail against the thread).
Hope this helps (also sometimes it can be that you need to turn in the battery slightly harder, or less hard, then you had it; and that then contact gets established).
Good luck

thanks for some extra info ,
but I finally noticed is different build of atomiser here
cos the atomiser is handmade here thus there is bound to have some don;t peform well some perform well.
I compare again yesterday with fresh cart and fresh battery .
clean up both atomiser and noticed again same this atomiser don;t perform well have to draw hard and vapour is less
whereas another one easy draw and vapour is decent.
I took off the cart and look inside the atomiser heating coil.
noticed the one that perform well , the heating coil is nicely made
whereas the under performing one , the heating coil is not nicely made...
so I can conclude is one of the atomiser is not welly made and thus peforming wise is not good.
my supplier willing to changed new one , but I don;t wish to ship back.
who knows I got another underperforming atomiser here?
so I now just like that used it ..see how the future go..than
cheers
