Is it possible to solar charge both the AC70 and the B80 setup as the expansion battery on the AC70 at the same time? What cable is need to do this if it is possible?
Graham
Hello, could you please tell me the specifications of your solar panels?
@gjbushman @BLUETTI
The B80 battery only has a 2 way interface cable to the AC60, not the AC70. The only way to connect the B80 to the AC70 is in power bank mode using the optional Power Bank Cable noted in the B80 uuser manual.
This cable is not a 2 way cable, it purely transfers power from the B80 to the AC70 at 200W max.
You can then connect to the B80’s DC input with a solar panel of 200W max and 28Voc. (A nominal 200W 12V panel) As you are using the AC70’s DC input port to connect to the B80, there is no method of simultaneously charging the AC70 from solar. In this way, the B80 is being charged via solar and it in turn is charging the AC70.
Methodology is also important for extending run time. - During the daytime (solar hours) disconnect the B80 from the AC70. This then allows you to run the AC70 and input solar to it from one panel. At the same time, connect a second solar panel to the B80 and charge it.
At night time, disconnect solar from the AC70 and plug in the B80 via the power bank cable. This extends you total overnight capacity to 1,574Wh. 
No equipment has been purchased at this point.
Thanks. This is very helpful. So the location is remote and not manned 24/7. If I want the AC70 to provide a constant 12v to the location and allow the AC70 and B80 to be solar charged constantly, keeping the B80 in power bank mode, then I will need two solar panels, one for the AC70 and one for the B80. Is this correct? Thanks.