Apparatus for generating a voltage surge which can be in the form of a voltage pulse. More specifically, the invention is an apparatus in which low voltage sources charge in parallel and discharge in series to generate a voltage sufficient to drive devices such as, but not limited to, a solenoid. The low voltage sources can be rechargeable batteries such as, but not limited to, 1.5 V or 9 V batteries or a combination of different voltage rechargeable batteries. The apparatus comprises one or more modules in which a battery is directed to charge in parallel but discharge in series. The switch-over from charging to discharging is by means of transistors in each module that cause the modules to discharge in unison thereby creating a voltage surge which can be in the form of a voltage pulse.