Bests & Worsts Reviews from Amazon

My wife loves drinking tea, so I bought this for her for Christmas. Six days later, we're returning it. Why? 1. It's not an actual thermos. If you put hot water in a regular glass cup, you'll get the same level of thermal insulation. To test this, she put some tea in a regular thermos and some in the smart mug. An hour later, the smart mug's tea was cold and the thermos still kept it hot. This was with the power off. None of this should be a problem if the mug keeps the liquid at the temperature you set it at when you turn it on, right? Correct, BUT IT WASN'T DOING THAT! Even while on and set at a specific temperature, it was dropping below. And since the insulation in the mug is terrible, it puts tremendous strain on the battery. Which leads me to point #2 2. The claimed three hour battery life. The battery was dying after an hour. Probably because since the insulation in the cup is so poor, the heater has to fight like the dickens right from the beginning to keep the liquid inside hot. 3. The amount of liquid it can hold. While it can hold a small mug's worth of liquid at 12 ounces, the reality is that since it's a travel mug and (supposedly) has a three hour battery life, it should hold enough liquid to make all of this worth-while. At an absolutely minimum, it should hold 16 oz, but I'd prefer 24 ounces. 24 ounces is enough space to last you a few hours. 12 ounces is what you can drink in one sitting. But let's be honest: it wasn't able to keep 12 ounces hot. 24 ounces would probably be impossible with the technology they're using. At the end of the day, the idea is great but the execution in many ways is poor. Save your money and just buy a good thermos!