standby power supply

I have a standby power supply to provide 60Vac with 12vbatteries.

12v batteries are in series to provide 36VDC. In case of power failure, battery supply voltages to provide 60Vac.

If I connected 1 battery (insted of 3), can we tell how much voltage the circuit produce.

Is it less tahn 60V or no volts at all?

Can anybody give me some idea befor I am going to do some paly with it.

Many thanks,

Be more specific.
This depend basically from inverter circuit. I mean: no output voltage, because the function blocked by low battery detector.