I have a 120 V / 60 Hz 2000 watt inverter which can draw up to 200 amps from a 12 V DC battery source. An AC oil heater drawing 6 amps max 15 amps is running from the inverter constantly. I want to automatically change batteries without interrupting the current to the inverter.
The scenario is: several batteries are supplying the inverter. When a battery becomes depleted it is replaced with a charged battery. The invertor cannot go off line so a battery must be on line at all times. The depleted battery is switched to a charging circuit until it is fully charged then it is available to be switched to the inverter load. The battery being charged must be isolated from the inverter during charging.
Having many batteries is not an issue. Having many battery chargers is not an issue.
Currently this is a manual process and I'd like it to be automatic. I'm looking for: the best way to detect the depleted battery, swap the battery from the inveter to the charge circuit, detect the fully charged state then return the battery to the load circuit.
This application is an off grid. Any advice will be helpful.