I have a 5kw Mecer inverter with 4 x 200ah lithium batteries in series. 2 x 450w panels. During the day the panels charge and eskom takes over when sun goes down. However we used too much power and inverter switched off. Set to switch of at 42v. It only switched back on when sun came up regardless of eskom coming on earlier. Set for charging either through solar or eskom. How do I get the unit to switch on when eskom comes back as it has happened twice now