I am looking to run a 24v inverter in my Citreon Xsara Picasso to power two 1300w coffee machines. does the configuration in the picture look right to you? Would both batteries charge from the alternator when in series? Any thoughts or guidance very welcome. Thanks
That configuration would yield 24 volts to the converter, but there will be a HUGE spark and possible battery explosion if you close that switch.
You need a battery isolator - you should peruse camping and RV forums on how this kind of thing can be handled.
Please don't install and close that switch!
Don’t do this : if you close that switch on the grey wires you show you directly short the two batteries together.
Where are the series connections that you think will allow the alternator to charge the two batteries?
Consider a split charge relay to charge the second battery.
Then consider a 12v water heater powered from the second battery and a percolator coffee pot...