I just use the guts out of these small 1v or 2v voltmeters. Then use a series dropping resistor to put the needle near mid-scale on a fully charged battery. Typically, the meters run about 2K ohms. So for a 1 volt meter, you'd need about a 23K resistor for a 6.3v battery to put the needle at mid-scale .5v Jack E/NJ
