I unplug the charger then plug it back in and let the light bar go solid again but I haven't noticed any improvement.
A good charger will not start charging a battery with less than a certain voltage. I think that's typically around 4V rather than the 4.2V the battery will have fully charged. If the charger did start charging a 4.2V battery, it would just drive the voltage higher, which is not good. It will reduce the life of the battery and if the voltage goes over 4.3 the battery will start heating up which is even worse.