i have a black&decker smart charger 25.10.2 amp with 75amp engine start .. since it is a smart charger it can stay connected on float charge, although i have never left it hooked up for more than 24 hrs.. now it comes up with code f03 does anyone use one of these chargers?? have hooked it up to three batteries and shows same code ... i use a battery tender ,i keep hooked up to my goldwing checked all three batteries it says all three are good... anyway of checking a battery charger???