You got this all backwards. The inverter doesn’t charge the battery. The converter does. When on shore power 120V AC is supplied to the converter which converts 120V AC to 12v DC which then powers the 12v distribution circuits. The converter also charges the battery. If you shut off the converter the battery takes over powering the 12V system. That’s how you test for a good battery: turn on 12v lights and then shut off the converter. If your 12v lights stay on that means the battery is doing its job and powers those lights when the converter is off. This is also what happens when shore power is removed…. You’re back to being battery powered only. An inverter however, takes 12v DC and changes it to 120v AC.
There is power loss when 120 v is converted to 12 v. Would you use less electricity if you ran the 12 v system on the batteries and just use the converter to charge the batteries?
Hi,
Yes you would use slightly less as conversion from 110 to 12 'costs" 10%
