Red tops, like many other non deep cycle batteries will not last many cycles if used without an alternator.

Yellow tops are deep cycle batteries, and can be used without an alternator.

FYI: I have a yellow top Optima in my Coronet that is 10 years old this month and still going strong.

The quality now is not what it used to be. The last 3 red-tops I purchased lasted less than 1 year. I won't be buying any more.