Using this Bluetti P090D to DC7909 cable, you can connect the Bluetti B230/B300/B300K battery to a Bluetti AC180P or AC180 Power Station. This allows you to charge the Bluetti AC180P or AC180 Power Station via the Bluetti B230 or B300 battery so this will give you extra battery capacity.
Press and hold the battery power button for about 10 seconds until the indicator flashes and the connection with the Power Station is established.
Note: The Bluetti B230, B300 and B300K battery will not be charged via the P090D to DC7909 cable over the AC180P or AC180.