I'm one of those people that cannot STAND drinking even "kinda hot" coffee or tea. I'm also not a fast drinker. So, it's a constant microwave-drink-microwave-drink situation. As a teacher, I found that my drinks would get cold long before they were even a fourth of the way gone. And TEACHER NEEDS HER COFFEE/TEA. :D I'd used various mug warmers with special mugs to transmit heat, and they're not great. There's always a thick skin that forms on top, some of them make your drink so hot it burns, or it's still not hot enough. And you've also then got this hot burner plate on your desk. And, you have to have the plate everywhere you go (so, car/classroom/various house places are obviously not an option). Travel mugs, even the expensive Yetis and etc are OK. But they really still don't keep it hot enough, long enough. And I can't microwave them. THEN, there is the fact that I like a decent amount of half-and-half or table cream in my drinks... which at times cools my drinks down so much I have to heat them back up right away. Or, I've tried heating up the half and half/cream first. So freaking fussy and annoying. I discovered heated mugs, and I was very excited for my first purchase. I did a lot of review reading and analyzing what was most important to me before I purchased. In the end, I went with this Ember travel mug (purchased September 2021). The base has worked just fine. It heats it exactly to the temp that I want. However, the battery life is SO POOR that even when I have it on the charger (wall or car) it only keeps my drink hot for a max of about 3 hours. That's ON the charger. PS: I like my drinks at around 139-141 depending on the drink. Anyway. Really poor battery life, but, again, I've just been so incredibly happy to have a hot drink until I'm done drinking. Enter the LID for this mug. You cannot take it apart, you cannot clean out the interior. AT ALL. A little bit ago I noticed that it seemed like there was some "stuff" inside the tiny hole underneath (tiny meaning probably 1/4 of an inch, tops). When you push the top of the lid up and down to open and close, there's some little plastic parts inside underneath you can see flip back and forth. And inside there, there's all this room for.... MOLDY stuff. I'm not one of those people constantly leaving my old coffee in there for days. I can't say I've never done it, but this mug is so expensive that I've been ridiculously good about it. I clean it every day and put it up on the charger to charge until the next morning. Regardless, there it was --- pale brown stuff inside there. There was no way to clean it. I started wondering if it was really moldy old cream, and I was drinking all my drinks through that moldy crap.... and it was really grossing me out... So. I really got looking and knew that I was right about the gunk in there. First, I soaked it in a solution of very hot water with a little dish soap and a drop of bleach. Soaked overnight, then tried tapping the lid on the side of the sink. A few gross pieces came out - enough to corroborate my theory, totally gross me out, and show me that there was even MORE inside there that I couldn't get out. I tried using a pipe cleaner to gently swipe inside, nothing would come out - and this tiny tiny little plastic door thing then broke and the mug wouldn't push open and close. UGH. So, I realized that with the lid already broken, AND full of 6 months of rotten molding drinks, I decided I'd just break the interior of the lid out. That way at least I could put the ring back on and be able to still use the mug. (the rim of the mug without the lid at all is not really functional as a drinking cup). So, I got out my clippers and started the lid demolition. It took a fair bit of strength, time, clipping, and cursing for the stuff in side to come out. Then I got a few photos for you all to see what I'm talking about. GROSS. (*Side note, readers, my cup is NOT DEFECTIVE -- this is the way it is designed! If you use creamy drinks in your mug, it will happen to you!) So, now I have a very expensive mug without a lid. And, I am a big girl, I don't NEED a sippy cup. But it definitely reduces it's use outside of the home. Sad face. A few other issues: The travel charger is really inconvenient. No chargers are compatible with USB. You can only use their charger, even the car one (cigarette lighter end). The travel charger is challenging to have fit in most cup holders. The mug wants to kind of fall out and roll around while driving around corners, etc. Lastly, it's just plain really expensive for what you get. I've been incredibly happy having a hot drink for an hour, but seriously? It costs enough money that I'm always scared I'm going to drop it. Bang it. Crack it. It's like this "precious thing" ------- and I have a hard time managing my stuff as it is. I don't like the anxiety that comes with this. A $100 mug? I could likely deal. Even the travel charger is so much money, and such a PITA. The fit sucks, like I said, but you certainly can't use any other cups/etc in that cup holder while using the charger. So, I'm storing the travel charger in my car when it's not in use. And it was pricey enough, too, that I'm like, "Oh, jeez, crap, is that the cord hanging out?!" and etc. It's just another thing for me to stress about a kid stepping on, etc. I wouldn't purchase this mug again.