I have a mecer 5kva inverter and a bsl lithium ion battery. On two occasions around 4 o, clock in the afternoon I have found the inverter has switched off and I am running on battery alone. While the sun is shining and setting 1 is on sol. On the first occasion the battery was depleted and the inverter refused to reset. On the second occasion I caught it in time and have some reset te inverter It is a new thing it is doing and I am at a loss to understand why it is doing this. If I go away I fear I will not be able to reset the system. Any advice?