I've been using the vise alto for almost a year now. I buy 2 cartridges every week or so. At least HALF of all the cartridges I buy are unusable or defective. Even if the cartridge is visibly full, more often than not they don't hit/produce vapor. I have had completely full, unused cartridges straight from the box that just don't work. The battery is not the issue, it is the cartridges themselves. Customer service is unhelpful and simply recommends buying another cartridge. They will offer a refund, but it takes up to 6 weeks to be reimbursed, in which time I have already bought multiple replacements... that also may or may not work. User's recommendation: DO NOT PURCHASE VUSE ALTO.