I have ordered a hybrid system with the Multiplus and decided to go with a Lithium Ion battery. I have sized the battery so that it will store almost enough for nighttime use if limiting it to a 70% DOD (recommended by battery supplier for long life). This means that the grid will need to kick in and supply the shortfall once the batteries reach their limit. Obviously if the gris fails at that point we will have no power. The question is, is that an acceptable mode of operation?
The second question is if it is a cloudy day and the batteries don't quite get to 100%, can it be set that the grid charges the balance?