For anything over a month I would at least use a Battery Tender on the 12VDC battery.
ExCivilian's main battery advice seems prudent as well however, which will of course also integrally maintain the 12VDC.
You may want to add just a bit more air to the tires too as they are constantly outgassing a bit (unless filled with larger molecule pure nitrogen).
Otherwise long term storage in a pure EV is far less complex than an ICE vehicle.
Oh yeah, mice love all vehicles. Sound/heat/firewall insulation for nests and wire insulation chewing to manage their teeth. More so in Winter when local cats are taking a break. I've used an under-hood sonic deterrent on vehicles stored outside to good effect. Likely not an OP concern but thought I'd mention as I've been a victim of same. 😣