I have seen the excel sheet you have prepared for design of solar panel inverter and battery bank and it is awesome.
Calculate size of solar panel battery bank and inverter excel.
In reality however inverters consume some of the power that flows from the battery while inverting.
I want to maintain the 70 c temperature of 50 liters approx water using 500 w dc heater for 24 7.
The solar battery calculator applies the best practices for using the depth of discharge dod of different types of solar batteries thus ensuring the optimal compromise between the size of the battery bank and the desired long life of the batteries while taking into account their type.
All we have to do is find the current through the controller by using power voltage x current.
This requires an increase in current flow from the battery to run the inverter.
If inverters were 100 efficient all of the power flowing from the battery would be inverted for use by the load and the inverter would consume no power at all.
Once you have sized your battery bank and solar panel array determining which charge controller to use is comparatively straight forward.
Take the power produced by the solar panels and divide by the voltage of the batteries.
Think of this as the minimum battery bank size based on your typical usage.
You may want to consider 600 800 amp hours of capacity based on this example depending on your budget and other factors.