If a battery is inserted backwards in parallel or series/parallel wiring or in some series connections, leakage and/or battery rupture may occur.
(a battery; is inserted backwards; in parallel or series/parallel wiring or in some series connections) (leakage and/or battery rupture; may occur; )
a battery leakage and/or battery rupture
is inserted backwards may occur
in parallel or series/parallel wiring or in some series connections