Summary: The FT1's chest strap contains user-replaceable batteries, but owners must send the wrist unit back to the manufacturer for a new battery (*Est. $13 plus shipping) if the monitor is out of warranty. The battery lasts about two years and Polar includes a two-year warranty. FT1 owners don't have much to say one way or another about customer service. In reviews of other Polar products, users tend to take one of two views: excellent or slightly unsatisfactory.