Could you elaborate on the neutral grounding plug? I have the same issue not being able to charge via AC while my ac300 is feeding my transfer switch. I thought the only workaround was the t500 adapter plugged directly into the b300 batteries? What is this neutral grounding plug you speak of, and will it allow me to charge via AC while powering the transfer switch?
Yes, same problem here, which is why I purchased the T500, which has worked fairly well as a workaround, minus the fact that it cannot turn on automatically only when the battery is low.
Currently I have the T500 powering the AC300 via MC4 PV connection, using one of the two PV inputs. Running directly into the battery is also an option, but not good for the long-term health of the battery to charge and discharge simultaneously.
I was hoping to find a cable or adapter to run the T500 into the AC input of the AC300 but apparently that is not possible. Theoretically, that configuration would allow for the T 500 to turn on at low battery percentage.
I am not aware of any magic cables or adapters to resolve this issue, but I am currently testing various options:
The transfer switch ground and neutral are not bonded at the panel, but the issue remains. Next, I might try lifting the ground of the transfer switch.
I ordered a neutral ground bonding plug from Amazon which will supposedly switch the AC 300 from floating neutral to bonded, when plugged into the front panel. Will be testing that soon to see if it resolves the issue.