I have an update from Advexure about the process in getting batteries from them and trust me it is legit. If you can find somewhere faster to get them then feel free. Advexure is a great group of guys though so it's a good honest place to order from. Here's how their battery situation works as of now. Just like any other dealer, the Mavics and batteries are in short supply, it doesn't really matter where you order from. When I order, I like to choose a place with the best communication and reliability, so far, Advexure has been the best for me and i've ordered from many places on the internet.
Batches of Mavic batteries continue to arrive into our warehouse each week on a limited basis. All backorders are fulfilled first and any remaining units in each batch will be reflected in stock at Advexure.com until they sell out. As of now, the best way to secure batteries is by submitting a backorder and we will fulfill your backorder as soon as we can when batteries shipments arrive into our warehouses.
Devin