Whichever 1.3v adapter/battery approach you, I urge you to try it. The LunaPro is a fantastic meter and should serve the vast majority of your needs, if your needs are anything like mine. With the adapter I see the same battery check phenomenon that you mention... the needle goes past the batt check markings. The meter gives me good exposure reading and I've never had any reason from looking at results to think that it has been steering me wrong. Good luck whichever way you go.