According to Jack :
What type of preparation is necessary for a sealed, so-called
maintenance free 12-volt battery for garden tractors?

Seem to recall reading somewhere that it has to be charged first. Can
you give me some more details as to amount of time, etc? My charger
doesn't have the safety feature that prevents overcharging. Any other
prep necessary?

Like auto batteries, most of the time such batteries come either precharged,
or the dealer charges them for you when you buy them.

So stick it in the tractor and see if it starts it.

If not, stick it on your charger for 4-6 hours, and that should start the
tractor.

Once the tractor is running mow the lawn and let its alternator/generator
top it up.
--
Chris Lewis, Una confibula non set est
It's not just anyone who gets a Starship Cruiser class named after them.