Low Battery on Forerunner 405/405CX/410 Despite Being Fully Charged

Although the age of these devices likely mean their battery performance is significantly degraded from when they were first purchased, if you have fully charged your Forerunner 405, 405CX, or 410 and receive a battery low banner after only a short period of use, the battery gauge may improperly read the remaining power left in your device's battery.

To Calibrate the Battery Gauge:

1. Charge device for 4 hours (not overnight, just 4 hours)

2. Disconnect device from Charger and acquire satellites

3. Start the timer

4. Allow device to fully discharge and shut off

5. Repeat steps 1-4

6. Charge to 100% normally

This may correct the battery low banner message after being fully charged. If not, you should consider replacing the watch.