B300 Output DC power via the Battery Expansion Port?

I got my cable today and I can confirm it works! B300 to AC70P from the expansion port #1 to the PV input (see pic). I measured about 51.2VDC rather than 58VDC at the XT60 connector with the B300 in power bank mode, but at 10A that still exceeds the max of 500W input!

Glad it worked for you. In this powerbank mode, you can use the mppt and solar at the same time, directly on the B300 solar input (200W max). If you want more solar charging, you have to take a d050s which can go up to 500w (via the dc7909 input for the AC-DC adapter).

The output voltage of the B300 depends on the energy level remaining in the battery and the power used… When my B230 is full, in powerbank mode, and the power consumed is zero, the measured voltage goes up to 55V or a little more. On the other hand, when the battery level is low, and the power output is high… The voltage drops below 49V.

Good point. My B300 was at 100% when I measured 51.2V.

Edit: I rechecked the voltage and I get 53V @ 100% SOC.

Does the B300 automatically turn off after some time when it’s in power bank mode? I was gone for several hours and when I returned home it was turned off. If it does timeout, is there a way to prevent it from turning off?

my b230 in powerbank mode constantly powers a grid tie inverter and it has never stopped. In your case I assume that your B300 may have turned off when your ac70p was fully charged and was no longer consuming power from the B300 for a long time.
To prevent the B300 from turning off, you can try this : Press the DC button on your B300 to turn on the DC and keep it on. I think it could work.

Great idea! I’ll try that and see how it goes. Thanks!

With the DC turned on, the B300 stayed in power bank mode more than 5 hours, so I think turning on the DC output does prevent the B300 from shutting down.

Thanks for your feedback!