I am including here a schematic of the electrical system upgrade I did on Ipanema following the installation of Battleborn lithium batteries. The system is similar to that described by Brian for SV Delos with a few small differences.  On the schematic, all new devices are in orange and new connections in red.  Given that I installed the 5KW inverter next to the battery compartment it can generate enough power to run pretty much all the AC devices of Ipanema (not at the same time of course).  The main aim of the design was to minimize the need to modify any ac electrical connections inside the boat.  The only change I did was to add two relay switches to avoid the use of the battery chargers when the inverter was ON but still allow their use when the Genset was ON.  The main feature of the design was to use the already existing white box in the engine compartment that, in my boat had originally two electrical outlets: one for direct 220 V shore power and one for 120 shore power transformed to 220 V.  All I had to do was to bring the output of the 5KW inverter into a third outlet on the engine compartment white box via 30 amp 3 wire AC cable. (Not easy but a lot easier than passing several large DC cables from an inverter/charger installed in the engine compartment.  Here, the inverter is kept out of the engine compartment avoiding the heat while keeping the replacement battery chargers in the engine compartment and keeping the two existing medium-sized DC cables sending the charge to the battery bank.  Another advantage of this approach is that the Genset can be turned on at any time, and the existing AMEL solenoid automatically disconnects any connected AC power source connected on the white box.  To avoid the possibility that the battery chargers could remain active while the Genset was OFF and the inverter ON and connected as the power source on the white box,  I added two small 220V-220V relays to the ac panel to automatically turn OFF the input AC current to the battery chargers if the inverter was left ON. 

 

 I have used this system for more than 6 months in the Caribbean with excellent results.  Because we have a 60 Hz power source in most of the marinas of the Caribbean, I connect the 5 KW 240 volt 50 Hz inverter to the white box, if I am at a marina with 60Hz shore power, when I need to use the cloth, or the dishwashers, or the microwave oven, which need to be run with 50 Hz.
I have also used the water maker with the batteries for one hour, and during a second hour turned on the Genset to keep making water and charging 160 amps back into the batteries. So for one hour of Genset, I get two hours of water making.  Also, I have been able to cool the boat for a couple of hours before going to bed by running the AC with the lithium batteries leaving plenty of energy in the batteries to keep the standard DC loads running overnight before a good sunny morning helps the solar panels bring the batteries back to full. 

 In summary, this approach is simple to implement, leaves the AMEL AC circuits virtually intact, allows the use of all the AC 50 Hz devices, and more importantly, is simple to use.  No need to think about changing different switches for different conditions to create specific results.
Hope this can help anyone thinking to make the jump to Lithium

Jose Venegas
Ipanema SM2K 278
RedFrog Marina, Bocas del Toro, Panama