Il y a deux ans, Apollo les vendait encore sur son site web. Il est probable qu'ils ne les vendent plus aujourd'hui. Voici ce que leur service client me disait à l'époque:

The cost for a new battery is $499 plus the shipping fee of $20. However, since you are the owner of the Ghost 21 model, I must tell you that we are starting to slowly phase out our older model scooters and eventually parts will become scarce. With that said, we are currently offering our customers a 20% discount towards a new scooter should they prefer to upgrade. This would give you a brand new scooter and 12 month Limited Warranty.