Ember Coffee Mug and Ember Travel Mug Charging: Our updated charging coaster charges both first and second generation Ember coffee mugs and travel mugs and keeps beverages at your preferred temperature all day long (between 120°F - 145°F) Heat or Charge with Ease: Place your Ember temperature control mug on the coaster to keep your drink warm all day; The coaster will maintain your coffee cup's current charge; Once it's empty or powered off, the coaster will automatically start charging Auto Off and On: When your heated coffee mug's battery is fully charged, charging shuts off automatically; Ember Mugs also have "maintenance charging", which means that if left on the coaster for several months, the battery is periodically topped off Easy To Use: Simply place your Ember mug on the charging coaster to use it; The coaster will charge an Ember mug's empty battery in approximately 2 hours; Once the LED turns green your mug is 100% charged The Ultimate Convenience: Let the experience of Ember last all day long with an extra Charging Coaster; Enjoy the convenience of having one coaster in the kitchen and another in the office, so your Ember is always ready wherever you are