How Much of My House Can I Run Off a Backup Battery?


Are you curious if your house can run off a backup battery? The demand for dependable energy spikes every year and working from home has only exposed the deficiencies in our power systems. Plus, what do you do when bad weather knocks out power for days and you still have deadlines to meet?

People are increasingly turning to a home battery as power back-up.  There are many advantages too -they are greener, quieter than generators, and can help you save a lot on electricity costs. But just how well covered are you with a home battery? Can it run your entire home and for how long? We’ll answer these questions for you in this article.

How Much Power Backup you Need

A home backup battery system connects directly to the power grid and stores energy from it. When the power goes out, the battery automatically disconnects and creates a self-subsistent power grid that powers homes.

A backup battery may serve your needs perfectly but be insufficient for somebody else. With that said, you can’t decide your backup battery size until you determine your needs, how long you need it to run, and its capacity(measured in kilowatt-hours)

It would be great if we could back up our entire home instead of just the essentials.  But the era we live in virtually lives on energy slurping devices. The truth is a standard home battery backup works optimally when they work on rotation and the number of appliances is drastically reduced. Here are additional factors that determine whether a home battery will work for your whole home or not.

Off-Grid Home

If you’re still holding on to a 20-year-old refrigerator for any reason, you may be using 1,700 kWh of electricity each year instead of just 450 kWh. If you combine this with an energy-guzzling AC and a plugged-in pool, your needs cannot be met by a backup battery.

Additionally your fridge might need 450 watts to keep it running, but 4 times that amount just to start it. To have a clear picture of just how much energy your appliances use, add it up or use home energy monitors. The fewer gadgets you need, the more likely that your entire home can run on a backup battery.

Cost of Backup Battery

The maintenance cost of a backup battery system is little to none. However, the upfront costs of a backup battery are high- $10,000 to 20,000 – and may keep many people from getting one.  

A typical lithium-ion battery system cannot run a house through a night of power blackout. These systems don’t have sufficient power to run many appliances either. Although these needs can be met by buying multiple batteries and inverters, it is not economically viable to buy inverters with more than 20 kilowatts of power or over 40 kilowatt-hours of batteries.

However, you can power your home with a battery by avoiding AC, some chargers (240EV), and stoves. Work with between 4 to 8 smaller circuits to keep your fridge running, light the home, communication and entertainment.

Solar-Coupled Battery Backup System

However much energy you need, a well-designed solar backup battery can match up to your needs when you get one with particular characteristics.

For example, the kilowatt-hours and the inverter output should be matched to the needs of the home when the battery is partially discharged. You should limit the number of circuits to discourage plugging in too many devices, and the solar system should be big enough to partially recharge the backup battery even on a gloomy day.

You can also use smart controls to automatically disconnect appliances that use a lot of energy or smart electric panel tech to manage every circuit in your home.

For more information on backup batteries, feel free to contact us and we’ll be glad to assist.