Batteries showing fully charged on the charger and not in the camera is often down to dirty or worn contacts if you rub them lightly with a pencil and then use the eraser head to clean them up it usually sorts this out, both on the batteries and the charger pins.
3rd party batteries often have better quality contacts than the Canon ones, and the BP 511A are certainly a better finish than the plating on the original BP 511s
Hope that helps.