Coffee maker off inverter and battery in a truck camper

Talking about used batteries.
In the past my bus conversion had 4 golf-cart batteries for house bank.
At the time I was making 1l of coffee (over a quart) every morning, we used the power for water pump (decent showers with 100 gallons tanks) and old-fashion lights with fridge and w/h control boards.
The batteries needed recharging on day 3 or 4. I had $2600 inverter/charger in the bus, who was doing excelent job and in 12 years I remember adding water to batteries twice.