No charge showing from solar [EB150]

I have a EB150 that is connected to a 395W solar panel.

I have connected the Bluetti DC7909 cable to the panel using MC4.

Using a multi-meter I can see that the voltage coming out is around 44V and on the cloudy day yesterday I could get around 2.5A [Testing from end of DC7909].

With the EB150 being partially discharged to 4 bars, the LCD did not show any Watts being input.

After about 30 seconds the LCD would turn off (probably normal operation I guess).

After waiting 30 minutes, nothing seems to have changed.

Do you have any ideas what is wrong?

Is the polarity of the DC7909 connector correct? Positive on the inner connection and negative on the outer connection? You panel may be reversed.

if not…

Sounds like you may not have sufficient sun exposere or have a bad wire to MC4 connection or the MC4 not making good connection itself. To check that, disconnect both MC4 connectors and snap back together firmly. If still no go, unscrew the MC4 connector round nuts and instpect that the wire is firmly atached to the connector contact. Sometimes this will get broken when people have difficulty pulling apart the MC4 connection.

Ah, looks like this could be the problem.
Would I have done any damage having this the wrong way?

Only way to know is to correct the polarity issue and tray again. If it now works, you should be fine. If it does not work, then yes, damage is likely.


The AC charging still works, so I am hopeful. I will visit the cabin in a couple of weeks and try again.
As I live a couple of km from the Tokyo service centre I will pop in and get it tested anyway.