It all started when the design team from Cauldryn was told it was impossible to boil water from a battery they said "it requires TOO MUCH ENERGY" 18 months later we were in full production. Cauldryn is the only patented bottle designed and built that can control beverage temperature at a range between 0°-212°. Cauldryn bottles were designed to provide hot beverages anywhere at any time and keep them hot for 10+hours.