New Zealand you wont be coming through customs, if you are in transit, so that's not a worry.
You are limited to 100ml liquid in your carry on luggage. Put your chargers in with any other computer stuff you have, wrap each battery in bubble wrap to keep them seperate, from each other, they can and should be in your carry on luggage. Place upto 100ml of liquid in a zip lock bag and put in your carry on. Customs in New Zealand know what e cigs are I can't say for Australia but would think it will be similar.
If you are at Auckland International Airport there is a smoker's area where you can vape with no worries near the escalators. just ask for directions at information if you can't find it. I vape there I have not tried to vape within the main airport area not worth the problems I feel. Can you pack the rest of your liquid in well sealed bottles then zip lock bags and put it in your checked baggage same as you would put shampoo etc.
Enjoy your trip