my own understanding is that if one were to use the Apple USB/AC charger
for the reader, you should be able to trickle charge the unit but nowhere near
as fast as using a regular AC charger. I will test this when I get home, but I
see no reason why it should not work. The only stipulation (as mentioned in
the past) make sure you use the SUPPLIED USB cable, as some cables do not
automatically have charging capabilities. Some just sync and others just charge
and the one Sony supplies does Both simultaneously.