If you want to buy a battery from a shop / dealer it has to be prepped which means you can't take the battery until later in the day or the next day because some batteries take longer to prepare.
We have tried to make things easier by prepping some of the more popular batteries but you can't prep them all plus, keeping alot of batteries charged is a logistical headache if you are a busy shop .
Not sure if you can buy a battery online anymore but in my opinion if you want to buy a battery call ahead and order / pay for it before you arrive , just an idea .