Ember Mug 3 Review: A Desk Mug First, a Portable Second

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In this guide

THE SHORT VERSION

The last stretch of a slowly drunk coffee goes cold at the desk, and the usual fix is a walk to the microwave. The Ember Mug 3 attacks that walk: a heater and sensors inside the vessel hold the drink at a temperature you choose while you stay in the chair. Mug 3 is the first Ember mug Ember clears for the dishwasher and the first with a temperature button on the mug itself, and it ships with a sliding lid that stretches a charge past three hours. It costs $149.95 in the 14 oz size and $129.95 in the 10 oz, sold direct by Ember, shipping free.

Three numbers from Ember's own pages shape the purchase. Off its coaster without the lid, the 14 oz holds 135°F for about 80 minutes; the 10 oz manages about 90. With the sliding lid on, the rating rises to over three hours, and on the included coaster the mug holds all day. A mug that lives beside the keyboard gets the third number for free; anyone who plans to carry it between rooms all morning is buying the first, and the first is the weakest of the three. Both battery figures are Ember's ratings, published with a caveat for ambient conditions, lid use, and starting temperature.

Our verdict

At $149.95, buy the Mug 3 when a drink sits an hour or more at a desk with an outlet for the coaster; skip it if the cup empties in twenty minutes or must travel all day.

A good fit for: A desk worker who sips one coffee or tea across a morning, keeps the coaster plugged in beside the keyboard, and wants the dishwasher to take the mug and its lid.
We would skip it if: You empty the cup while it is still hot, you need heat beyond the battery's roughly 80 untethered minutes, or a permanently occupied outlet and a wipe-only coaster will annoy you.

Reasons to consider it

On-mug temperature control: five presets from 125 to 145°F, no app or pairing needed
First dishwasher-safe Ember mug, mug and sliding lid together on the upper rack
Charging coaster included and covered for life; the mug holds temperature all day docked

The compromises

Ember rates about 80 minutes of holding off the coaster for the 14 oz without the lid
Dishwasher terms are top rack and low-temperature cycle only; the coaster can never be immersed
Temperatures between the five presets exist only in the app, and the presets themselves are fixed

What we have not verified: Battery and temperature figures here are Ember's published ratings, not reproduced. Ember publishes no dimensions or weight for Mug 3, no charge-time figure, and no Mug 3-specific number for the app's temperature range, and nothing on the pages says how the battery holds up after a year of daily dishwasher-and-dock cycles.

The things in this guide

A closer look at the products, who they may suit, and what to check before buying.

The desk mug for drinks that outlast the first hour

Ember Mug 3 · 14 oz, Black

Five presets from 125 to 145°F set on the mug without any app, a heater that holds the chosen temperature while the mug sits off its coaster, and top-rack dishwasher care for the mug and its included sliding lid.

Before you buy: Off the coaster, Ember rates about 80 minutes at 135°F for the 14 oz without the lid; between-preset temperatures exist only in the app, and the coaster is wipe-clean, always-plugged equipment.

$149.95 at Ember

Price checked October 10, 2026. Retailer prices can change.

A desk with an outlet is the mug's natural habitat

The match is specific. You pour a fresh cup at the start of a work session, leave the preset at 135°F, and drink across two or three hours while the coaster keeps the battery topped up between sips. The heater holds the temperature you picked through the last third of the cup, and the dishwasher takes the mug and its sliding lid on the upper rack, so the care routine matches any ordinary mug.

The mismatch is just as specific. Anyone who finishes a cup in twenty minutes is paying to hold a temperature the drink never outlasts; a ceramic mug from any kitchen shop does that job. Whoever wants hot coffee through a morning of meetings away from the desk runs into the 80-minute figure, and the sliding lid only lifts it past three hours. The coaster also wants one wall socket permanently, and it is wipe-only equipment: no dishwasher, no sink, wiped dry with a cloth, and unplugged first.

Mug 2 to Mug 3: the button, the dots, the dishwasher

Ember's own pages state the changes, and the first is control. Mug 3 is, in Ember's words, the first Ember Mug with on-mug temperature control: a button under the base shows the current setting on the first tap and moves through five presets on the taps after — 125, 130, 135, 140, and 145°F, with the mug shipping at 135°F. The presets are fixed and cannot be renamed. On a Mug 2, the same support center explains, the mug holds its default 135°F but only the app can change the setting.

The second change is the row of five small lights under the main status light, which show the temperature setting when tapped and the battery level in roughly 20-percent steps while the mug charges; earlier Ember mugs carry a single light with no dots. The third is cleaning: dishwasher use is new with Mug 3, and Ember says Mug and Mug 2 remain hand wash only. The fourth is the sliding lid included in the box, which lifts the battery rating past three hours. Mug 2 itself stays supported, and its coaster charges Mug 3.

The battery numbers decide where the mug can live

Ember's figures, in full: on one charge, off the coaster, the 14 oz mug holds 135°F for about 80 minutes and the 10 oz for about 90; with the included sliding lid the rating rises to over three hours; on the coaster the mug holds all day. Ember attaches a caveat — battery life varies with ambient conditions, lid use, and starting temperature — so read all three as ratings for a filled mug, not promises for every cup.

The coaster is the charger, not a hot plate. The heater and sensors sit inside the mug, and Ember's technology page says the mug maintains its chosen temperature even when lifted from the coaster; the 80 minutes and the three hours measure exactly that untethered window. The plain reading is that Mug 3 is a desk appliance with a battery for brief trips, not a travel mug: nothing in Ember's numbers covers a working day away from the dock, and the lid is the difference between the 80-minute figure and the three-hour one.

The dishwasher rules are narrow but real

Mug 3 is the first dishwasher-safe Ember mug, under two conditions Ember states together: top rack only, low-temperature cycle only. The sliding lid goes in on the same terms. Hand washing remains available and the mug is fully submersible, with a note to skip long soaks.

The coaster sits outside all of it: never in the dishwasher, never immersed — unplug first and wipe with a clean dry cloth. Before the mug docks again, the silver charging rings on its base and the pins on the coaster must be dry, which makes toweling the base a permanent step after every wash cycle. Ember also rules out the microwave entirely, metal utensils and abrasive scrubbers on the coating, and the dishwasher for customized or branded mugs. The mug, then, cleans like ordinary dishware; the coaster stays an appliance you only wipe.

Two sizes, one $20 step, no color surcharge

The 14 oz lists at $149.95 in all eight colors — Black, White, Sage Green, Sandstone, Salt Blue, Matcha Green, Lavender, and Powder Blue — so color costs nothing within the size. The 10 oz, in just Black and White, lists at $129.95; moving up a size is $20 on $129.95, about 15 percent more for four more ounces of capacity, and Ember specs the 14 oz at 414 ml. On October 10, the 14 oz was in stock across its colors, the 10 oz White was in stock, and the 10 oz Black and both Stainless Steel Edition variants were marked unavailable.

The sliding lid is included at no charge; Ember values it at $14.95 and lists a sliding lid as an accessory at that same price in both sizes, though that listing is titled for Mug 2 and does not state Mug 3 compatibility on the page. Beyond that, the page has no accessories priced into the purchase: the coaster and charging cable are in the box, and the only buying decision on the page is 10 oz against 14 oz, smaller pours against the everyday coffee size Ember itself merchandises as the default.

What the $149.95 does and does not include

Ember ships the mug, the sliding lid, the charging coaster, and its charging cable; the support FAQ adds a power adapter plus a guide to first setup, and the product page promises free shipping. Unused mugs are returnable for 30 days counting from delivery, and Ember charges a $10 restocking fee on returns. The warranties split in two: the mug carries a one-year limited warranty covering material and assembly faults — original purchaser, authorized sellers, with software and Bluetooth connectivity excluded — while the charging coaster is covered for life against charging failure, pins included.

Nothing beyond the box price is required to run the mug. The Ember app is optional; the support FAQ answers 'Do I need the app to use Mug 3?' with a no, and the app's extras are degree-level temperatures between the presets, LED color, battery detail, and firmware updates. Coffee Club is a separate subscription — $25 a month or $300 a year for coffee deliveries, with a gray 14 oz Mug 2 folded into the annual plan — and no part of buying or operating the Mug 3 asks for it.

What the pages leave out

Ember publishes no dimensions or weight for Mug 3 anywhere checked on October 10 — the printed specs stop at capacity, controls, display, battery, material, and box contents — so whether the 14 oz fits a specific cupholder or hand is unanswerable from Ember's own pages. There is no charge-time figure for Mug 3 either. The app's numeric range is a second gap: Ember documents 120 to 145°F for the earlier Mug and Mug 2, and says the Mug 3 app range works 'exactly as before', without printing the number against Mug 3 itself.

The battery figures carry Ember's own caveat for ambient conditions, lid use, and starting temperature, and nothing published says how the cell holds up after a year of daily dishwasher-and-dock cycles; the one-year mug warranty is Ember's own answer to that window. The purchase decision, in numbers: if a drink lasts past an hour at a desk with a socket, the 14 oz Black was $149.95 and in stock on October 10; if the cup empties within twenty minutes, an ordinary mug does the same job.

How we put this together

Built from the product pages and listings below, without test scores or results we have not measured. Specifications and prices change, so check the original page for the exact model, current price, delivery, and returns.

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