Guide to owning a battery

Lowering the cost of running your appliances or heating and cooling your home at night or during peak electricity times, by storing and using the energy your solar system generates when the sun is shining.

Reducing the use of fossil fuels needed to generate electricity in the evening.

Lowering NSW’s evening electricity demand will reduce the need for new power generation and distribution infrastructure.

Connecting your battery to a Virtual Power Plant (VPP) can provide you a payment for discharging energy in your battery when the grid needs it most. This incentive can speed up the time it takes to pay back the upfront cost of your solar and battery system.

Select a professional installer, or installation company, with a good reputation. Ensure they are, or use, qualified tradespersons by checking that their electrical tradesperson licence appears on the Service NSW website. You should also check that they are accredited by Solar Accreditation Australia (SAA) to install batteries.

Lithium-ion batteries are the most common type of battery technology used in solar battery installations. There are 2 main types of lithium-ion batteries, nickel manganese cobalt (NMC) and lithium iron phosphate (LFP). In most cases, you will need to look up whether a battery is NMC or LFP, as most fact sheets will only state ‘lithium-ion’. NMC type batteries are widely used in electric vehicles and in-home battery systems. In recent years the industry has started to shift towards LFP due to its longevity, which may make it cheaper to purchase, though good quality options can be found for both types.

Consult with your installer to choose a battery best suited to your energy needs and existing solar system. When comparing batteries, consider the warranty terms, brand reputation and consumer reviews. You can find suitable batteries accredited by a reputable industry body like the Clean Energy Council (CEC). For the battery installation incentive, the eligible batteries will be a selection of this list that meets certain requirements.

The battery’s warranty is critical for your protection and must meet a certain standard if you want to take advantage of the battery incentives. An in-depth guide to battery warranties can be found below.

Homes that use more energy during the late afternoon and evening will benefit the most from installing a battery. Homes that already use most of the energy produced by their solar panels, for example running appliances when the sun is shining, will see fewer savings from installing a battery. A reputable installer, such as one approved by Solar Accreditation Australia (SAA), will be able to help you interpret your energy use. You may also wish to use a tool such as SunSpot to estimate the savings achieved by adding a battery to your solar system.

You need to weigh up the upfront investment with the projected long-term savings for your situation and desire to capitalise on the other benefits of batteries, such as lower carbon footprint, higher grid independence, and resilience to blackouts.

Most homes with solar will already have a smart meter installed. If you don’t have one, your electricity retailer will provide one free of charge shortly after you install a solar system.

Homes with an outdated switchboard may need an upgrade to prepare for the installation of a solar and battery system. This can be quoted by an independent electrician or factored into your solar and battery quote if your chosen installer offers this service.

Although homes with solar will already have an inverter, some sites may require replacement of the existing inverter with one that is compatible with a battery. More details on inverters can be found below.

Before installing a new battery, ensure that your existing inverter is compatible. Your installer can provide guidance on this, but it is essential to confirm that the battery recommended by the installer is listed as compatible by the inverter manufacturer. This can prevent unnecessary costs and potential warranty issues. Some manufacturers offer inverter compatibility statements online that list batteries approved for use with an inverter.

Your installer is responsible for ensuring compliant design and compatibility, so we recommend you question them on this.

Using a battery and inverter that are not compatible can void the warranties for both components. Always verify compatibility to protect your investment.

Check your installer has current accreditation here. Get their advice to decide on a high-quality battery from a recommended manufacturer. Remember to shop around.

Consult your installer to select the installation location. The decision should consider bushfire and flooding risk, as well as internal factors, such as storage of fuels and chemicals nearby. Where possible, the battery should be installed away from habitable rooms, and ideally in utility areas such as garages, when protected by a bollard, or outside. Safety should always take precedence over appearance when positioning the battery.

It is recommended that your installer places a smoke detector near the battery. This will provide an alert for a potential battery fire or smoke from a fire elsewhere on the premises. If utilising the battery installation incentive a smoke alarm is required for indoor installations.

Read the battery manual and follow all guidelines from both the manufacturer and installer.

Check your battery for signs of damage, strange sounds or gases. Avoid anything that hinders ventilation, such as storing items too close or allowing leaves to pile up around the battery.  

Fire & Rescue NSW have published dedicated battery safety information that we recommend you familiarise yourself with.

Manufacturers may guarantee a fixed term in years (e.g. 10 years) or a set number of cycles over a battery’s lifetime, whichever comes first. A cycle refers to the number of times a battery is completely charged and discharged, often a daily occurrence for NSW households. For example, a battery that is warranted for 4,000 cycles equates to approximately 11 years (4,000 cycles / 365 days = 10.96 years).

Some manufacturers define a total amount of energy that the battery is warranted to discharge. This is often stated in terms of megawatt-hours (MWh). Similar to cycle warranties, throughput warranties typically only apply if your battery reaches its throughput limit within the warranty time period.

This is a guarantee that your battery will retain a certain amount of capacity throughout the warranty period. For example, many manufacturers guarantee that 70% of a battery’s original capacity will remain after 10 years.

This term describes how deeply the battery is discharged. If a battery has delivered 90% of its energy, and 10% energy is reserved, the DoD of this battery is 90%. For lithium-ion batteries, the DoD is typically 90-95% to maximise battery life.

This is the capacity of the battery that can be regularly discharged. For example, a typical 14 kWh battery has a usable capacity of 13.5 kWh.

The optimal ambient temperature range at which the battery can function without changes to power output or capacity.

The ambient temperature range in which your battery will remain covered by the manufacturer’s warranty.

Replace old light bulbs with LEDs, switch off appliances and lights when not in use, use less hot water, have shorter showers and wash clothes in cold water. Find out more ways you can less energy and save on your energy bills.

Insulation can help you use less energy on heating and cooling. Good building insulation, like ceiling batts, can help you recover its upfront costs from electricity saved faster than either solar systems or batteries.

Always check the energy rating labels when you are shopping for a new appliance. Energy efficient appliances, with at least four stars on their Energy Rating label, may cost less over the life of the product, despite a higher upfront cost. There are a range of incentives to help reduce the cost of energy-efficient upgrades, including for:

• air conditioners
• pool pumps
• hot water systems
• lighting.

If you are on a time of use tariff with your power supplier, look at options to consume your energy outside of peak times. For example, running the washing machine when a cheaper tariff is available, such as during the middle of the day.

If you have existing solar, run appliances when there is sunlight, pre-heat your house (in winter) or pre-cool your house (in summer).

Use these to cover more of your consumption in the evening and early morning. You could also receive a feed-in tariff payment for solar power exported to the grid.

Find the most competitively priced retailer to help you save money on electricity. Ask for discounts for direct debit or on-time payments. Visit energyswitch.service.nsw.gov.au to help find the most competitive offer.

Visit energysaver.nsw.gov.au for more tips on how to fine-tune the energy used in your home and save money on your power bills.