Seems you were running on inverter for your 120v needs and that ran the batteries down enough so the inverter shut down. There would still be enough battery to run the usual 12v things -lights, fans, etc.
When off-grid, you need to "power manage" what the inverter is running so the batteries can keep up. Put the fridge on propane, WH on propane, limit use of 120v appliances. When not watching it, unplug the TV set, don't just turn it "off", which leaves it on. All kinds of tricks to get by longer before you need to recharge the batteries.
At some stage you do need to recharge them, no big deal, but best if they can be done during the day instead of at 3am! :)
