you may be able to recharge one, there are some gimmics out there but i doubt they work, if it won't hold a charge replace it, they aren't expensive 20-40 dollars
Take it to Sears.
i dont see why not.
Magnetos
probably
the magneto
Yes .
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.
No, it is not necessary to remove it. You can charge it right there on the mower.