I use the small e-stick, this is the ONLY E-cig that I have been able to stay with for any length of time. It is the most realistic alternative to regular cigarettes I have found, and I have tried many ....... The charging case is very useful and is designed to easily carry with you. I find I use this's E-cig in a similar way to regular cigarettes, "smoking" it 15 - 20 puffs then returning it to the charger pack till next time. I am a heavy user and have 3 chargers so always have 1 fully charged 1in use and one on charge. Batteries and refill caps last very well. They are available at Lloyds Chemist and Tesco but they are better value on line.