Right, so essentially the effective voltage between the wall-wart output and the battery would be approximately 1.3V; with a resistor (or equivalent combination of resistors) of 1.3175kΩ in series, the current should be approximately 987µA... I admit this certainly doesn't seem likely to be able to cause the battery to overheat.
That should result in ~0.36C of charge being separated across the battery terminals every hour (to begin with, obviously the voltage, current, and rate of charge will all decrease as charging continues), though to work out the increase in voltage of the battery over time I believe the capacitance of the battery is required...