There are countless household appliances in every single house. One appliance with a low power rating would be a ceiling fan. On average ceiling fans consume roughly 60w and are found in the majority of houses. On the other side of the spectrum, we have a high power-rating appliance such as a microwave. Microwaves use anywhere between 1000w to 1800w of power in order to function correctly. This is very large power consumption and one of the highest power ratings found for appliances in a household.
No. You cannot rule out the battery even after the open circuit voltage measurement. The open-circuit voltage may not have changed but the battery's internal resistance may have greatly increased.
