malcolminthemiddle

I have a 5Kw solar system with back up batteries. Recently the back up batteries have failed to kick in when there is a mains power outage. If I simulate a power outage by turning off the main breaker the batteries kick in. If I turn off the main breaker during the power outage the batteries still fail to kick in. My installer has already reneged on his service agreement and is of no help. I have tried resetting the solar system by turning it off and back on. Any ideas? Thanks in advance.