When troubleshooting, always observe the color of the LED:
Table 3 LED Indications of Battery/Charger Status
No LED indication
Single green blink
Figure 1 Battery Charger
Battery is inserted incorrectly.
Successful charger power-up
Battery is unchargeable or not making
Battery is in rapid-charge mode.
Battery is in charger, not in rapid-charge
mode but waiting to be charged.
Battery is charged (to 90% or greater
Battery is fully charged.