I started out with a blu. It helped me cut back, but I still smoked analogs. Then I got a 510 starter kit that allowed me to kick the analogs, but I found that I still need to change batteries more that I wanted to. I ordered an eGo battery with the atomizer cover and charger. It came in the mail today at noon and I topped off the charge for an hour. I've been pulling off of this same battery since 1 (almost 12 hours) now. Cartos are a tight fit with the atty cover, but they are an awesome addition for uninturuptted vaping. I'll still use the 510 batteries but wow, 12 hours? AWESOME!