I learned, long ago, that turning solid-state electronics off-and-on tended to shorten life expectancy. So, I keep my BCD-3, BP17c and 4Bc on continuously.
I worried about the electric costs, as I have an all-electric house; however, it averages out to about $3 to $5 per month. Cheap insurance.
Depending on your $ per kilowatt hour, YMMV.