A battery for your CPAP, APAP or Bi-Level machine can be your saviour when a power cut strikes your area. A CPAP battery also enables you to take your sleep therapy machine with you wherever you go. Current battery models are a far cry from the heavy deep cycle marine type batteries of the last century. Most recent portable battery designs fit snugly under your machine and add little to the overall weight. Whether you are going camping, taking a long-haul flight or just cannot rely on the cruise ship's power supply, a battery is a sleep apnoea patient's best friend away from home.