Won't Charge Battery Again After Reaching 100%

[owensdj]

What would cause a Dell laptop to not charge the battery again until a reboot once the battery charge reaches 100%? If the power adapter is removed so that the charge stays under 100%, the system can continue to charge the battery, but once hitting 100% the system never charges the battery until the laptop is rebooted. This has been happening for some time now, and did it with different AC adapters.