Charging coaster pins physically sink or get stuck over time, causing complete loss of charging functionality.

“Both, Mug2 and Tumbler are garbage; charging coaster for both are useless. One of the pins on both coasters simply sunk to a point that there is insufficient contact.”

vs Marketing: Marketing claims 'all-day warmth on the charging coaster,' but users report the coaster pins mechanically fail, making all-day use impossible.

Mugs and charging coasters frequently fail within a year, with enamel flaking and complete product failure reported across 45 reviewed complaints.

“After spending 100's of dollars with nearly 100% failure rate in these 2 departments, I stopped buying them.”

vs Marketing: Marketing positions the mug as 'ideal for desk use' and a 'thoughtful gift,' but 45 reviewed complaints show products regularly fail within a year, rendering them unusable.

Battery degrades significantly within 2 years, dropping to under 30 minutes without a lid — less than half the marketed 80–90 minute claim.

“My mug is under 2 years old and without the lid in place, the battery dies in 30 minutes or less.”

vs Marketing: Marketing claims 80–90 min battery life and 'up to 1.5 hours,' but owners report sub-30-minute runtime on mugs under 2 years old, with no lid in place.

Customer support is described as non-existent across 31 reviewed complaints, leaving users with failed hardware and no resolution.

“Customer service is non existent!!! Most reviewers were let down by their experience overall. Consumers express significant dissatisfaction with the level of customer service provided.”

The Ember app constantly disconnects, requiring repeated setup and undermining the core app-based temperature control feature.

“I do hate that it CONSTANTLY disconnects from the app and I have to set it up again.”

vs Marketing: Marketing claims users can 'select your temperature with the Ember app' and receive notifications, but persistent disconnection makes reliable app control impractical.