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Charging Cable Does Not Work With Forerunner 645 Music
If you are coming to the Forerunner 645 Music from a previous device you will find that the charging cable from some previous Forerunner models physically fits the new Forerunner. However, due to the higher current requirements for Forerunner 645 Music it is important that the only the cable that came with it should be used. Although there is no safety concern with doing so, if you use the older cable with Forerunner 645 Music you will likely have difficulties with file transfers using Wi-Fi or USB. You may also receive a notice on the watch that states "Unsupported cable. Use provided cable to sync while charging." The newer model cable that came with your Forerunner 645 Music will work with older products. You can identify the newer cable by examining the USB plug end of the cable which is marked as “1.15 A max" as shown below: