What Is Solar Battery for Home

Home energy storage · Dec 5, 2022

What Is A Solar Battery?

A solar battery is an additional component of the Solar Photovoltaic (PV) system that stores energy and discharges power as and when needed. Solar batteries are mostly used in off-grid PV systems to store excess electricity. While some solar home batteries use wet cells, others use sealed or gel cell batteries. Each of these has different temperature, mounting, and ventilation requirements.

Although batteries for energy storage have been around for a while in both stand-alone (off-grid) and commercial backup (UPS) power systems, however, solar home batteries have become more prominent over the last few years.

How Does Solar Battery Storage Work?

When the solar panel receives sunlight, it converts the solar energy to electrical energy. The battery stores this electrical energy as DC electricity and the DC electricity would be transmitted into the inverter. Similarly, in the inverter, the DC electricity would convert to AC electricity. The converted energy can now be used by appliances and devices.

Factors to Consider When Choosing A Battery Type

There are several factors to consider when choosing a battery type for energy storage. These include:

  • Battery life and warranty
  • Power capacity
  • Depth of discharge (DoD) 
  • Round Trip Efficiency

Battery life and warranty: A battery’s lifespan generally ranges from 5 to 15 years. However, it is projected that the lifespan will increase over time. Also, warranties for batteries are generally stated in years or cycles. For instance, a battery can have a warranty of either ten years or 10,000 cycles, whichever comes first.

Power capacity: The power capacity of a battery refers to the total amount of electricity that the battery can store. Solar home batteries are usually stackable; this means you can have multiple battery storages at home to increase capacity.

Depth of Discharge: The DoD measures the degree to which a battery can be used relative to its total capacity. For example, if a battery has a 100% DoD, it means you can use the full battery storage amount to power your home. If a battery has a 94% DoD, you can use up to 94% of the battery capacity (e.g., for a 2.5kWh battery, you can only use 2.35kWh, which is 94% of 2.5kWh before the battery needs to be recharged).

Round Trip Efficiency: Round trip efficiency is the charging and discharging efficiency or losses incurred during cycle use. Unfortunately, the transfer of energy from one form to another, (and in this case from electrical to chemical energy), will always result in some energy losses. Generally, the charge and discharge losses from a lead-acid-based battery are close to 20%, while most lithium-ion batteries are usually within 5-8%.

Common Solar Battery Types

Lithium Ion

For reliable lifespan and DoD, lithium-ion is the best choice for a home solar battery; most solar home batteries use this technology. Lithium-ion batteries have a longer lifespan and higher DoD. They are more compact and have lower round-trip efficiency, although they are more expensive than other batteries. Examples of lithium-ion batteries include the Sonnen Batteries and Tesla Powerwall.


Lead acid batteries have been around for decades, and they are one of the cheapest for home energy storage in off-grid power systems. The downside of this solar battery type is that it gradually becomes outdated and has a lower DoD than other battery types.

Benefits of Using Solar Battery Storage

Solar battery storage enables energy independence. It maximizes solar self-consumption, thereby reducing the electricity needed from the grid.

A battery system provides backup power for a home or business. It allows uninterrupted electricity access by storing the excess solar energy produced during the day so that it is readily available when needed.

Batteries can help balance short-term power fluctuations, manage peak demand, and act as a backup to prevent or recover from power outages. Installing energy storage solutions also impacts the supply and demand of renewable energy. It enables cleaner energy sources to be more easily integrated into the electricity ecosystem.

Note that the design of a PV system should be compatible with the addition of a battery component. Also, if the primary purpose of adding a solar home battery is to reduce electricity bills, ensure that the solar system is producing enough energy to charge the battery once it has met the daily energy demand. If not, consider increasing the solar PV capacity to provide excess energy.

Franklin Home Power

Franklin Home Power is a home energy management system that manages and tracks energy use and consumption in the home. It allows the users to monitor their past and present energy consumption while controlling their appliances and devices attached to the system during off-peak or shoulder periods. This feature enables users to save more and spend less on energy bills.

With Franklin Home Power, you can implement different economic and energy-saving electricity schemes in the home. Franklin home power has several amazing features such as:

  • Bill saving
  • Solar black start
  • Generator backup management 
  • Smart circuit management

Integrating Franklin home power with a solar PV system comes with huge benefits. It enables users to utilize energy consumption by turning on devices when the solar panels are receiving sunlight. You can schedule appliances to operate based on whether panels are receiving sunlight, the capacity of the battery, and even the time-of-use tariffs for electricity from the grid.

With Franklin Home Power, your home is assured of reliable and sustainable energy storage. Your home needs our LFP AC coupled battery-which stores energy up to 43 MWh and has a 12-year warranty.

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