@BLUETTI just posted this on the Facebook group page…
So if you just picked up a new b230/b300 get ahold of firstname.lastname@example.org with your original ac200/ac200p order/contribution number as well as the order number of your new battery purchase, and they’ll send you over a free cable ( P090D-XT90 , XT90-Aviation Plug ) that’ll allow you to connect the expansion to your unit.
Note: Valid only for AC200/AC200P purchases prior to August 20th, 2021
This offer will end on September 30th, limited quantity, first come, first served. (The estimated retail price for this cable would be around $80.)