Hello,
I have an MPPT 100/20-48v charge controller charging 2x 120Ah lead acid batteries in series. I want to drive an inverter (around 1000W) from these batteries to run a conventional fridge/freezer for X hours a day (with an Automatic Transfer Switch (ATS) to fall back to mains when the battery voltage falls below a certain threshold).
As we know, you must connect the inverter directly to the battery as the MPPT controller cannot supply more than 20A.
Problem is I dont 100% trust the ATS and I am very impressed with the MPPT load output features so I wanted to use the Automatic Load Disconnect of the controller to act as a fail-safe.
I had wanted to use the Victron Battery Protect (with remote control connected to the load output) to connect/disconnect the battery in the event of it becoming too low but I read this is forbidden.
I would have the ATS voltage threshold set to switch off and on the inverter mains at a slightly higher voltage to the MPPT, so in practice the fall-back device should not really be used unless the ATS fails.
Its odd such a "turn key" solution is not easily available for solar, as surely its a common requirement.
Dad reckons such a thing is feasible to make using an OPTO + heavy Mosfets and using the load output as a "remote control" signal to keep the battery connected, if the load output turns off, the Mosfets would disconnect the power.
Any advice would be appreciated?
Regards
Danny
