More often than not, the red cable hooks up to the positive post on the battery. There should be a mark on or by each battery post to indicate whether it is the positive (+) or the negative (-) post.
Red is normally positive.
Check voltage on battery 12 volt you should uses a 12 volt 2 amp battery charger connect red (positive) to the + side of battery and the black (negative) to the - side of the battery.
i dont see why not.
Magnetos
probably
the magneto
replace it
a rider will or an electric start will.
totally
I'm assuming its a riding lawn mower of some type. Our own lawn mowers of this type have an alternator in them that keeps the battery charged
Dead cell in battery, loose of corroded battery connections, or the charging system on the mower engine is defective.
This depends on the mower. With out knowing the make and model of the mower so I can look up the type of battery this question can not be answered
No, it is not necessary to remove it. You can charge it right there on the mower.