Vince,

The LCD screen is always on, but you can change the duration of the backlight.

I don't know how long alkaline batteries will last, but you may want to invest in some NiMH rechargeables. I swap them out about once every month. It saves a lot of money in the long run, and it's very satisfying to be able to put in a fresh set without feeling any guilt about whether or not all the energy has been drained out.

Scott