Go with the HG2. At 3000Mah at 50w you will vape forever on a single charge. That is at max power, but usually you will be using lower wattage than that. I only use 30w on my tank atty. Since I have a 200w box using 2 HG2s, at 30w I could probably go a week between charges. lol I usually only use the tank when I am going out or running low on juice though.