With solar panels on your roof, the next step is to store extra energy with a home battery. Adding a battery is the simple next step for Australian homeowners looking to get more from their existing solar energy setup.
Adding a home battery to your existing solar system without replacing the entire setup is easy to do with the right provider. How easy, depends on the age and the configuration of your homes system. This guide takes you through what to check and what to expect when planning the installation of a battery.
Can you add a battery to an existing solar system?
Most Australian residential solar systems can accommodate a battery, either with the existing inverter or with the addition of a separate battery inverter. How simple or complex the process of including a battery depends on your inverter type, the age of your system, and your switchboard configuration.
If your solar panel system was installed in the last five to seven years, there’s a chance it will be compatible already. Older systems may require more work, such as an inverter upgrade or a switchboard modification. Aa qualified installer can check your system and give you guidance on the additional steps and costs this may require.
Key things to check before adding a battery
Before retrofitting a home battery, there are a few checks needed to ensure the installation process is straightforward or if extra work is needed.
Available space
Batteries need a suitable location at your home, this could be a garage wall, somewhere accessible, or close to your switchboard and shaded from the afternoon sun. There are requirements around ventilation, temperature, clearance from other features in the home, and protection from direct weather. An accredited installer can advise you on the best placement for your property as part of your assessment. Learn more with our home battery location fact sheet.
Your current solar system’s output
A battery can store the extra energy your solar system generates, as well as what you import from the grid. It helps if you understand how much your panels are exporting. If your system is small or your daytime energy usage is high, there may not be enough excess solar to charge your battery, however you may want a battery to help power your home when solar isn't enough. If you choose to install a battery you also may want to consider upgrading your solar panels at the same time to ensure you’re getting the best solar generation. Our What size battery do I need? page explains how solar panel output and home battery needs work together.
Your switchboard
Adding a battery may require an upgrade to your electrical switchboard, especially if it’s an older model or it doesn’t meet current safety standards. A licensed electrician can assess this as part of the installation process. Upgrading your switchboard may add to the overall cost but is necessary for safe operation.
Your inverter type
If you have a hybrid inverter (one designed to work with solar panels and a home battery), adding a battery can be relatively easy as the capability is built into the inverter. If you have a standard solar inverter, you may need to replace it with a hybrid model or install a separate battery inverter. Zelora does site assessments prior to any install, so any inverter upgrades can be discussed with an accredited installer.
Standard solar inverters
These handle solar generation only and to add a battery, you’ll need either a separate battery inverter (called an AC coupled setup) or a full inverter replacement. AC coupling is a common way to retrofit a battery as it lets you keep your existing solar inverter in place and adds the battery through an independent unit.
Older systems
Inverters have a lifespan of around 10 to 15 years, if you have an older system, it may be worth replacing rather than updating. If your inverter is due for replacement, upgrading to a hybrid model at the same time can be more cost-effective than installing a separate battery inverter. Systems with micro-inverters or older string inverter models may have compatibility requirements that an installer will need to assess on site. Your home battery compatibility should always be confirmed by a qualified professional this is something your provider can work with you on.
What changes (and what doesn’t) when you add a home battery
Adding a home battery changes how your solar energy is managed, but it doesn’t alter how your solar system works. The panels continue to generate electricity the same way, with the only difference being what happens to the extra energy.
Without a battery, extra solar energy is exported to the grid, and you receive a feed-in tariff. With a battery, the extra is stored to be used by your household later in the evening or overnight. Energy will still be export if the battery is full, and you can still draw from the grid if the battery runs out, but your household reliance on the grid should decrease.
Your electricity retailer and billing arrangement will stay the same. You’ll still receive a bill, though the amount should be lower because more of your solar energy is being used rather than exported at a lower rate.
Adding a battery to your home shouldn’t affect your solar panel warranty, but modifications to your inverter or the wiring could impact the inverter manufacturer’s warranty depending on the terms. You should confirm this with the installer and review your existing warranty documentation before any work begins.
‘My system is too old for a battery’
Older systems may need additional work, such as an inverter upgrade or switchboard modifications. However, many can still be adapted to include a battery, your provider can arrange for a qualified installer to assess your household setup.
‘Adding a battery means replacing my entire solar system’
Your existing solar panels and wiring can stay in place. The main change would be if your inverter needs to be upgraded or replaced. A full system replacement is not often needed, unless the existing parts are damaged.
‘I’ll be completely off the grid with a battery’
For many Australian households, a battery reduces your reliance on the grid, it doesn’t remove the need to use the grid completely. Going fully off grid would require a much larger system, significant bigger battery capacity, and a backup generator.
‘I can install a battery myself’
Battery installation is electrical work that must be carried out by a licensed professional. It involves working with your switchboard, inverters, and the grid connection. Self-installation is unsafe and likely to void warranties and breach regulations.
Does my inverter support a home battery?
Hybrid inverters are designed to work with batteries directly. Standard solar inverters can still support a battery with an AC coupling or by being replaced with a hybrid model. A qualified installer can check the inverter’s specifications and recommend the best approach for your system.
What if my solar system is old?
Older systems can still accommodate a battery; however, it may require additional work such as an inverter replacement or switchboard upgrade. If your system is more than 10 years old, it’s worth having a qualified installer assess the battery compatibility and the condition of your existing components.
Will adding a battery affect my solar warranty?
Adding a battery should not affect your solar panel warranty. However, modifications to the inverter or electrical system could impact the inverter warranty depending on the manufacturer’s terms. Check your existing warranty documents and discuss this with your installer before proceeding.
Is it hard to add a battery to solar?
For most systems, the process is straight forward for a qualified installer to complete. Older or more complex systems may require extra work, but the process is well understood in the Australian market. The key is having a proper assessment done first to work out the requirements.
What size battery should I add to my existing system?
The right battery size depends on how much extra solar your panels produce and how much energy you use in the evening or overnight. A battery that’s too large could sit unused, and one that’s too small won’t make a difference. Read ‘What size home battery do I need?’ to learn more.
Is there a way to add a battery without paying upfront?
Some providers offer subscription, or financing [AR1] [AR2] that cover the battery equipment, installation, and the maintenance for a monthly or weekly fee. This option can make retrofitting more accessible if upfront costs are a barrier. Read our Can I get solar panels and battery installed where I live? page to see how these models work.
Next steps
If you’re considering adding battery storage to your existing solar system, the first step is to check your inverter type, age, review your recent electricity bills to understand how much solar you’re exporting, and consider what a battery will achieve, is it lower bills, backup power, or both.
From there, you can have a qualified installer assess your system for compatibility and recommend a battery size and configuration that fits your usage and household. If you’re unsure where to start on sizing, read out What size home battery do I need? page.
Take your time to get an assessment, ask questions, and make sure the solar panel and battery solution fits your home and your budget. The right sized battery can add great value to your home.