Some Forerunner devices utilize a user-replaceable battery. Reference the FAQ, "How do I change the battery in my FR70, FR60, or Forerunner 50?" for assistance with this process.
Many of our Forerunner devices utilize a rechargeable, lithium ion battery that is not user replaceable. If a new battery is needed, it can be replaced by utilizing the Garmin RMA process or contacting your local Garmin support office at www.garmin.com/support
Often power issues are not related to a battery failure. If your Forerunner is not charging or is quickly losing power, try cleaning the charging contacts on the back of the device and on the charging equipment with rubbing alcohol and a Q-tip. This will remove any possible residue.
If a battery power issue is still present, it is possible the issue is software related, in which a software update is suggested. The software can be updated using Garmin Express.