Let's say the audio output is 2 Watts which is a number people seem to use. If you only have 2.4V to start with, you need 1 Amp of current considering power conversion losses when trying to double the voltage to the 5V or so that the audio system needs. Then you add the processor power requirements and it's not hard to imagine such currents.
Pretty much all charging circuits are configured as current sources so even a dead short does not damage the circuit. As with any charging circuit, the design surely accounts for user error such as a short or plugging the battery in backwards. Again a current source design handles this situation.
The 5V "open-circuit" (unloaded) voltage of the PS2-3V charging circuit has been discussed before. Take a voltmeter and hook it up to the battery terminals with nothing connected and if you find otherwise you have a busted charger. Or have GGG or GRJ measure what the voltage charges up to on their 1.5F or 2.5F capacitors..
