sorry
you need a 'latching' relay that is operated by a momentary push button
a regular relay uses power when activated
using it means it will draw power when activated
so if your kill switch is wired to activate the relay , to break/disconnect the circuit in storage it becomes the load and drsins the battery
if wired so normally disconnected and only connects when turned on, it bevomes an extra loa drawing power even though all lights etc are turned off
you need either a latching relay, which only draws power when opening or closing and then latches/locks in position
or
you need a manual battery disconnect switch mounted at the batteries
