I am thinking of mounting a voltage divider (two 10k resistors) between the battery + and - pads. in addition to connections to a 3.7V LiPo battery. The center of the divider would connect to pin D0/A0 for monitoring the battery voltage.
My questions are: when additionally connected to USB, as for re-charging the battery, how much voltage is the charging circuit applying to charge the battery, will this over-drive pin A0, and will the additional drain (from the voltage divider) adversely affect the charging circuit?