How to Calculate the Size of Your Home Backup Battery System: Load Estimation Techniques

Home energy storage · Feb 25, 2023

A home backup battery system can provide a reliable source of power during unexpected outages or emergencies.

However, to ensure that your backup battery system can effectively power your home, it is essential to calculate the appropriate size of the system. This involves estimating the total load that your home requires and selecting a battery system that can provide enough power to meet those demands.

Determine Your Home's Average Power Consumption

The first step in estimating your home's power needs is to determine your average power consumption.

You can do this by reviewing your utility bills to identify your monthly energy usage. Alternatively, you can use a power meter to measure the power consumption of each appliance in your home over a period.

Once you have this information, you can calculate your average daily energy consumption.

Not all appliances in your home require backup power during an outage. You should focus on identifying critical loads, such as refrigerators, lighting, heating or cooling systems, and communication devices.

You can refer to the user manuals of these appliances to determine their power consumption.

Determine the Duration of Backup Power You Need

The next step is to determine how long you need your backup battery system to provide power.

This will depend on your location and the frequency and duration of power outages in your area. For example, if you live in an area prone to extended power outages, you may need a larger battery system that can provide power for several days.

To do this, add up the power consumption of all critical loads that require backup power, and multiply this by the number of hours you need the backup power to last.

For example, if your critical loads require 2,000 watts of power and you need backup power for 24 hours, your total load would be 48,000 watt-hours (2,000 watts x 24 hours).

Once you have determined your total load, you can select a battery system that can meet your power needs.

Battery systems are rated in terms of their energy storage capacity, typically in kilowatt-hours (kWh). You should select a battery system that has enough storage capacity to meet your total load.

For example, if your total load is 48,000 watt-hours, you should select a battery system with a storage capacity of at least 48 kWh.

In addition to energy storage capacity, there are other factors to consider when selecting a battery system, such as its efficiency, charging time, and depth of discharge.

A deeper discharge means the battery can provide more energy, but it can also reduce the battery's lifespan.

You should also consider the type of battery, such as lead-acid or lithium-ion, as well as the warranty and maintenance requirements.

Consult a Professional

Calculating the size of your home backup battery system can be complex, especially if you have a large home or unique power needs.

If you are unsure of how to estimate your power needs or select the right battery system, it is recommended to consult a professional. An experienced electrician or solar installer can assess your home's power needs and recommend the best battery system for your needs and budget.

FranklinWH Energy Management and Storage

FranklinWH energy management and storage is a whole-home energy solution containing two primary units: aPower and aGate.

The aGate is the energy management device that is the brain of whole-home energy management. It connects the grid, generator, photovoltaic, loads, collects status information of the aPower's PCS and BMS, and utilizes Ethernet, Wi-Fi, and 4G signal for external communication.

The aPower is the energy storage unit with a built-in inverter, which can generate 10 kW peak discharge power and mighty start capability for heavy loads like air conditioners and pumps. A large capacity is also necessary to be capable of such a discharge power. Each aPower has a 13.6 kWh capacity and is expandable to 15 units per aGate with 204 kWh power backup.

Homeowners can use the FranklinWH App to monitor and control the system remotely. There are backup, load shifting, and self-consumption modes to best suit homeowners’ needs, providing optimized energy and backup power to the home, lowering electricity bills, or living completely off-grid.

Conclusion

A home backup battery system can provide peace of mind and ensure that you have power during an unexpected outage or emergency.

However, to ensure that your backup battery system can effectively power your home, it is essential to accurately estimate your power needs and select the appropriate battery system.

By following the load estimation techniques outlined in this article, you can confidently select a battery system that will best suit your needs.