Hmmm ok. See both the wife, and I are heavy vapers. The wife goes through about 4-5 808 batteries during the course of the day, and who knows how many carto's she fills. I gave up on carto's awhile back, and went to tanks. First using the eGo B types, then to a CE-5 Clearomizer. I gave her my old eGo 650 batteries (and 808 to 510 adapters) when the eGO-T 18650 mod's came out. I snapped up one (with a couple of batteries) and never looked back. She still uses her Bloog 808's when out and about, but when watching TV, or just hanging around the house she'll use the eGo battery since she feels the eGo is too big to carry around in her pocketbook. PLus she doesn't care for manuals. The 18650 battery will last me about 2 days before needing a recharge.