Why does a keyboard need to go to sleep.
 

Online I see for sale a wireless keyboard/mouse, and it says about it

"Auto Sleep And Wake Feature

This keyboard also features an auto sleep and auto wake mode. If there
is a long period of inactivity, the keyboard will automatically go into
a sleep mode. To exit sleep mode, press any key."

Why does it have any need to go to sleep. Why would it use any power
if no one is pressing a key? This is not a cordless phone that waits
for phone calls, whose battery drains even when not in use.

(For that matter. why don't cordless phones have on/off switches. They
can go without charging for about 2 days. If you could rely on the
ringer in the other room and turn the cordless phone OFF, they wouldnt'
need a charge for 10 days or more. )

This is the item. Before you buy it, there's a newer version now.
http://www.amazon.com/FAVI-FE01-BL-W...wifi+keyboards

Thanks.