put kill where? at battery post, and is just a switch,
not those dynamic battery drop relays?
if the battery goes dead with the neg. lug pulled the battery is bad.
end of life , battery.
the lug pull never lies.... ever.
if stays ok now this is called battery phantom drain.
(or aka. dark currents)
finding cause takes an ammeter. any,
here is all ways to find a drain.