I read in the user's manual that the backlight can be turned on and off.
I don't know how long the unit would run on the batteries with the backlight
off.

I find the 2000c to be virtually un-viewable without the backlight
on.

Since I have it permanently plugged into ship's power, that's not a
problem for me. However, if I needed a GPS for use in a plane without
an electrical system, this would be serious drawback.
--
Jay Honeck
Iowa City, IA
(Presently in Memphis, TN)
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"