Bests & Worsts Reviews from Amazon

I have had my Ember mug since November 2016 and absolutely love it, so I was curious about some of the 3 star and lower reviews. Upon reading these, it is clear that a number of purchasers (and potential purchasers) don't fully understand how the mug actually works. Ember really needs to do a much better job of explaining this (probably with a cute, animated video), but here is what is actually going on: It looks like many people think that this is a battery operated/heated mug - not an unreasonable asasumption since you do, after all, have to charge the battery. What really happens is much more interesting. Inside the walls of the mug is something that is called a Phase Changer Material (PCM). When I brew a cup of coffee in my Keurig coffee maker directly into the mug, the initial temperature is about 175 degrees with a target of 140 degrees. What the Ember mug does is to extract the heat from the coffee and store it in the PCM. In this case, the material starts out in a waxy form and liquifies as it absorbs heat. This fairly quickly cools the coffee down to the desired temperature, but in the process the PCM becomes a heat storage "battery". Once the coffee reaches 140 degrees and starts to cool, the mug senses this and extracts heat from the PCM "battery" and uses that to maintain the temperature rather than directly heating the coffee using normal battery power. If you understand this is how it works, then it is easy to understand why some people are not happy with the battery life. Basically, the hotter the initial temperature, the more storage capacity in the PCM "battery", and the longer it can maintain the coffee at the desired temperature. My coffee maker at my cabin is a smaller unit that requires me to brew the coffee into a measuring cup and pour it into the Ember mug. I also noticed that the initial temperature there is about 154 degrees. That means that the Ember mug at my cabin can't maintain my ideal coffee temperature for as long as it does at home because the PCM "battery" is not as fully charged. In fact, one day I got busy and forgot to pour the coffee into the Ember mug until it was just under 140 degrees. Normally I would expect the mug to quickly heat the coffee to the desired 140 degree temperature, but with essentially no PCM "battery" charge, it took longer than usual to get to the desired temperature and I am sure it would not have maintained the temperature for very long. So, once you understand this, you will realize that want to brew directly into the mug if possible and transfer it to the charger until it is ready to drink if you can do that. If not, as soon as your coffee is brewed, make sure you transfer it into the Ember mug as soon as you can and it will be able maintain the desired temperature for the maximum period of time. If you do this, I think you will find that you will have no issues with how long the Ember mug can maintain the desired temperature. Ember really needs to explain this to customers. In addition to a video on their website, a simple "How Your Ember Mug Works" sheet will go a long way to solving this issue. A couple of other comments and one suggestion for Ember Mug II. I actually had a problem with the electronics in my original mug. I found that Ember customer support was very responsive and when they couldn't fix the unit, they quickly sent me a replacement. I also had a problem with the lid in the replacement mug not locking open after a few weeks and they replaced that quickly as well. This is a first generation product so I am pretty tolerant of issues like this as long as the company is responsive, as Ember was. My suggestion for Ember is to make the next version use wireless induction charging, so there are no issues with the bottom of the mug needing to stay dry to make good contact with the charger. Enjoy your constant temperature coffee/tea. It really is a completely new experience...