Having trouble with wii sensor bar?

My wii ultimate sensor bar is just not working correctly! It's not the normal sensor bar--it's a large white one that works with batteries and has a different selection between wide and standard range. However, I just put new batteries in it, turned it on and selected the one hour shut off setting. After an hour it shut off, but now it wont go back on and the batteries are BRAND NEW! I just don't understand why it's not working right...anyone have any ideas?