Is there a battery that'll only charge from Solar, but provide power from wall-plug when empty?

[Vich2]

I wanna connect a few panels off-grid to run some critical appliances like frig and dishwasher, but I need grid power to kick in when it's 80% drained.

Preferably I'd like to minimize how much charge it takes from the grid, to minimize solar waste.

I'm thinking maybe 1kW of panels and 2KWh battery. So, enough to charge the battery with the surplus, and also enough to make it through the night powering the frig and the internet.

In other words. A programmable battery source to specify how much it'll charge from the grid.

 

[Rocketman]

Over budget path.
This is available to do with a Victron system. But it will blow your above budget.

Multiplus inverter
Battery monitor- BMV712 or smartphone
SCC mppt
Cerbo.
Any lithium battery

By running some Assistants (programs) in the Cerbo and Multiplus, you can tell it to not charge from grid (unless you tell it to), and if the SOC gets lower than 20% then go into bypass mode and use grid power for the load. Once batteries are above____% (say 40%) then go back to inverting.

You will need enough solar to charge to battery to 100% at least once a week - while powering the loads or the state of charge will get off. (And the cells balance will get way off too).

Fridges are a low power item - usually 100-200w.
Dishwashers are a HIGH load item (because of the electric heat).