When I end my commute, I generally have only 3 bars on my battery gauge, and the morning commute requires heavy charging when I start. Has anybody figured out a way to hook up a battery charger to the main batteries so I can avoid the morining charge cycle?
nope. At least not in a practical manner. A 200 volt charger isn't something readily available. Then getting it connected so it wouldn't damage any of the computers that control the battery, possible but not likely, but if you do please post the schematics for the rest of us.
You wouldn't neccessarily like the results, either: very roughly this would use about 5 kW-hours of power, or about half as much as your house uses in a day. Would you want to increase your electric bill by 50%? This shows again that liquid hydrocarbons are a very dense form of energy storage.