My BEL express Li runs on two AA batteries for a month of regular use. I keep it way up high by the visor, works great. No wiring needed.
Cost $299 about 4 years ago, and after several years of use and falling off the windshield onto the dash, I sent it to the factory in several pieces last month. For $55 they sent me a like-new one within two weeks!
It covers all x, k, ka, laser etc... bands and has VG2 protection too.