I have the E900, which I believe is similar.
I normally swap the batteries for a spare set when charging, but on
one occasion when I removed the batteries for charging overnight I
found that the camera had reset itself - the camera appears to have a
capacitor to maintain settings while batteries are removed, but that
only holds up for a few hours.
However if you find that settings are lost as soon as you remove the
batteries, that's probably a fault.
Brilliant cameras though, wish they still did something similar.
Al