Perhaps the simple battery checker on my work bench?? It's probably me but why do I want something that draws battery power with each button press when I want the batteries to last as long as possible?? If it was so necessary why don't all fobs from every manufacturers have "check battery" lights or indicators.?? It's different for sure. Somehow I have gotten along with a fob who's indicator light hasn't worked for a while and never since I have owned the car, so I guess I'm not smart enough to see the value of this apparently "valuable" asset. At least I now know what it is supposed to be.