vCathy
A note on your idea of seeing more available power if the charger is left on after the green light comes on. I agree but probably more significantly Isidor Buchmann, President of Cadex Electronics, a real power in the battery testing and instrumentation field and author of the web ‘BatteryUniversity’ and several well know books on batteries, agrees too.
Buchmann calls the charge accumulated in that time the ‘Float’ charge. And says it adds to available energy. He doesn’t imply any disservice to the battery if you don’t do it, just less power from that charge cycle.
Buchmann also prescribes a ‘rest time’ after the charge is disconnected and before power is drawn as another way to get more energy. He says it allows time for the chemistries to get comfortable with each other.
Buchmann has, in his BatteryUniversity web page, a good table of ‘How to charge-when to charge’.