Your battery info file keeps track of what process has consumed the most from you battery so that you can make manual decisions about what services to run or shuit down to make your battery last longer. So you deleted the histroy and now have nothing to look at to tell us what was consuming your battery.
Do you really belive that a manfacturer as sophisticated as Motorola would write an algorythym to predict how much battery jucie is left based on histroical records? That algorythym would consume more power from the battery than to simply query the batteries amps and voltage values. Why would they do that?
When you calibrate your battery what you are doing is resetting the usage database. This can be useful if you have changed your usage patterns and want to see if it improved battery life.
Widgets consume a lot of power since they use your phone's radio to pick up new ads, gather weather data, update your data on the phone. This way you have instant access to the data for that widget. Turning them off consumes less battery, period. Also, turn off any sync settings that are not neccesary. If you absolutley have to know when someone posts something on your facebook the second they post it you will consume more battery life. If you can wait 15 minutes you will increase battery life dramatically.
Good luck with your theories.