Ember 2 Smart Mug review: The solution to cold coffee and tea has a 90 minute battery life

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When I get absorbed in work, I frequently forget about the cup of coffee on my desk until it's gone cold and lost its allure. You can pour it away and make a new cup, or give it a blast in the microwave, but neither is an ideal solution.

The Ember Mug 2 is the top smart mug in our best coffee mug guide because it aims to make your cold tea and coffee woes a thing of the past with temperature controls you can configure from your phone. A smart mug may sound ridiculous, and it's not a cheap purchase. I've gotten so used to it that after just one week of testing, I don't think I can go back to a regular mug.

If you want to take the Ember 2 on the go, check our our review of the Ember Travel Mug in our guide to the best coffee thermos.

Specs

The Ember Mug 2 is offered in black or white. It comes with its own charging coaster and a cable and power adapter for plugging it into an outlet. It's ceramic and has a good handle. The only indication it's not a regular mug is the Ember logo and the LED light below it. Turn it upside down and you'll also see the metal charging rings on the bottom and the power button.

Set-up process

After unboxing the Ember Mug 2, you'll want to plug the charging coaster in and set the mug on it to make sure the battery is fully charged. The Ember Mug 2 connects to your phone via Bluetooth. You have to download the Ember app for Android or iOS, create an account, and then pair your mug. It was quick and easy, and I was able to pair the mug with my Google Pixel 4 and start using it within five minutes. 

How it works

You configure your Ember Mug 2 using the mobile app and it's all very straightforward. The main screen says Empty until you put something in the mug, then it displays the temperature on a sliding scale along the bottom. 

Tap the arrow at the bottom, and you can see several presets for different drinks. A latte is set to 131 degrees Fahrenheit, for example, while green tea is set to 137 degrees. Choose your beverage and stick with the preset temperature, or swipe left or right to increase or decrease it to suit your personal preferences.

In the app, you can switch between Fahrenheit and Celsius, change the brightness of the LED, and set the LED color. The LED also changes color to signify different things, so red means low battery, solid white means your ideal temperature has been reached, and blue means it's updating the firmware.

Below the presets, you'll also find a Tea Timer section, which allows you to set an alarm for the perfect brew time. Once again, there are presets like three minutes for green tea or five minutes for black tea, and you can set your own timers for your preferred brew time. You can pair up to six Ember mugs with the app. 

What makes the Ember Mug 2 stand out

To kick off testing, I poured a cup of coffee, picked coffee in the presets (which defaults to a temperature of 134 degrees Fahrenheit), and set my mug aside to work. A short while later, my phone pinged with a notification telling me that my coffee had reached the ideal temperature to drink. I had a sip and it was perfect. The mug then maintains that temperature until you're finished, or until it runs out of battery. 

I've been washing it out and putting it back on the charging coaster in my kitchen late morning, and then it's ready for tea service in the afternoon. It takes about two hours to charge up fully. When you place it on the charger with a hot beverage inside, it will maintain that temperature indefinitely, though it won't recharge the battery any higher to avoid overheating. There is also a two-hour inactivity shut-off, so if you don't pick it up for two hours it will switch itself off. 

Cons to consider

It looks like a normal mug, but because the bottom section has to accommodate a battery and heating element, the capacity is limited. The 10-ounce Ember Mug 2 I've been testing is a little small for my tastes. There is a 14-ounce model, but it's an extra $30.  

The only other problem I've had is that sometimes it sends more than one notification about your drink being at the ideal temperature. This has only happened a couple of times in a week of testing, but it was a minor annoyance. You can only hand wash the Ember Mug 2 as the charging coils are not dishwasher safe. 

The bottom line

The Ember Mug 2 is the best smart mug around. It's surprisingly awesome having your coffee at that perfect drinking temperature for the entire cup. After a week of using the Ember Mug 2, I don't think I can go back to a normal mug. If you like your coffee, tea, and other hot beverages to be at the perfect drinking temperature, then you're going to fall in love with it.

Pros: Keeps drinks consistently warm, LED and smartphone notification alert you to the ideal temperature, has handy charging coaster, additional brew timer for tea

Cons: Expensive, limited mug capacity, limited battery life, not dishwasher safe