Palm has posted an article in their Support Knowledge Library about sync cradle compatibility and battery issues with the Treo 680. According to Palm, older sync cradles, such as the cradle kit for LifeDrive, Palm TX, Tungsten T5 and E2, and also older Treo 650 smartphones, are not compatible with Treo 680 smartphones. Using these older cradles with the Treo 680 could cause the following issues:
Reduced battery life: This can be caused by incorrect electrical signals being sent to the Treo 680 during charging in the cradle.
Background applications running without your knowledge: An incompatible cradle can cause unpredictable results, and possibly leave the smartphone in a state where background applications are running, such as the car kit application, even if the application has not been activated. You may notice that your indicator light (LED) is glowing solid green or red unexpectedly.
Smartphone can't sleep: The signals may prevent the smartphone from going into power saving ("sleep") mode, reducing your standby time.
Noticeably reduced battery life based on the above symptoms.
