Mistakes to Avoid When Buying a Solar Battery

Buying a solar battery should feel exciting. You want to save money on power bills. You want to be ready for blackouts. And you want to get more out of the solar panels you already paid for.

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However, most people do not understand how these batteries work. You might make decisions based on guesses or sales pitches. Then you’ll probably feel frustrated when your battery underperforms.

If you feel unsure, you are not alone. A lot of homeowners feel confused at this stage. The options sound technical. The numbers are hard to understand. And no one wants to waste thousands of dollars on a system that falls short.

At PSC Energy, we strive to be educators first. After all, an informed customer is a happy one. This article will make it easier for you. It is written in plain English and based on real stories.

In this article, you’ll learn about the following:

• Mistake 1: Going Too Small to Save Money
• Mistake 2: Buying Too Much Battery Storage “Just in Case”
• Mistake 3: Not Thinking About the Future
• Mistake 4: Not Checking Compatibility with Solar
• Mistake 5: Not Knowing the Difference Between Single-phase and Three-phase Backup
• Mistake 6: Choosing the Wrong Installer
• Mistake 7: Ignoring the Warranty and Support

By the end of this article, you will learn the most common mistakes people make when buying a solar battery and how to avoid them. You will walk away with simple advice that helps you choose the correct battery for your home, budget, and future.

Let’s start with the first mistake.

Mistake 1: Going Too Small to Save Money

Trying to save money is smart, but going too small can disappoint you. A cheap battery might seem like a good deal at first. But if it runs out too early or charges too quickly, it will not give you the backup or savings you expected.

For example, a young family with two children bought a 5 kilowatt-hour battery. Their home used over 20 kWh each day. The battery helped a little, but it was empty soon after dinner.

They still had to use grid power at night most of the time. They wished they had bought a 10kWh battery instead.

A battery that is too small will not reduce your power bill much. It also won’t help much during a blackout. You may still lose power before bedtime, which can be frustrating if you expect full coverage.

Tip: Think about your energy use in the evening and early morning. These are the times when solar panels do not work. Make sure your battery can power your most important appliances through those hours. A bigger battery that meets your real needs will feel more useful daily. You’ll be getting your money’s worth.

If you’re interested in learning a bit more about the benefits of solar batteries, you might want to start with the following article titled, 7 Benefits of Adding a Battery to Your Solar System.

Power up your savings. Click here.

Mistake 2: Buying Too Much Battery Storage “Just in Case”

Some people think it is safer to buy the biggest battery they can afford. They want to make sure they are ready for anything. They imagine extended blackouts or big savings. But a bigger battery is not always better.

Large batteries cost more. If your solar panels do not make enough extra energy to fill the battery each day, you are paying for storage you will not use. This can stretch out the time it takes to get your money back.

For example, a retired man living alone bought a 13.5 kilowatt-hour battery. He was in his home during the day when the solar was pumping and went to bed early. He only used about 6 kWh of electricity each evening. His battery often stayed half full. It looked impressive, but he paid thousands for energy storage he never needed.

If he had bought a smaller battery, he could have saved money. He also could have added more storage later if he needed it. Some battery systems, like the Sigenergy SigenStor, allow you to do this. Others do not.

Tip: Try to match your battery to your energy use. Look at how much power you use in the evening and how much solar energy you send back to the grid during the day. That will give you a better idea of the correct size.

If you’re interested in learning a bit more about solar batteries, you might want to start with the following article titled, Adding a Battery to a Solar System.

Let’s talk solar savings. click here.

Mistake 3: Not Thinking About the Future

Your energy use today might not be the same in a few years.

• You could buy an electric car.
• You might start working from home.
• You may even install a heat pump or upgrade your air conditioning.

All of these things use more electricity.

If your battery system cannot grow with your needs, you might have to replace the whole thing sooner than you expected. That can be expensive and stressful.

For example, a couple installed a battery that was just right for their small home. A year later, they bought an electric car. Their electricity use doubled. Their battery could not keep up, and not every battery is easily expandable. Their installer told them they would need a second system instead of a simple upgrade. That meant more cost and more hassle.

Some battery systems allow you to add more storage later. These are called modular systems. Others do not allow upgrades, or they make it very difficult.

Tip: Ask your installer if the battery system can grow over time. If your energy use might increase, plan for that now. Planning ahead is easier and cheaper than fixing the problem later.

If you’re interested in learning a bit more about expanding your energy system, you might want to check out the following article titled, Expanding Your Solar Panel System with Batteries and Add-Ons.

Ready to go solar? Click here.

Mistake 4: Not Checking Compatibility with Solar

Your solar battery must work well with your solar panels. If the two systems do not match, you might lose energy, waste money, or miss out on backup power during blackouts.

Some systems use a hybrid inverter. This type of inverter connects both the solar panels and the battery. It helps them work together more smoothly. Other systems use two inverters: one for the panels and one for the battery. This setup can work too, but it needs to be appropriately planned.

If the design is not done right, your battery might not charge fully. It might not turn on during a blackout. Or it might lose power as it moves through the system. These problems can be hard to fix after everything is installed.

For example, one homeowner installed solar panels and added a battery a year later. The two systems used different inverters and were not designed to work together. The owner had to spend more money to fix the wiring.

Tip: Ask your installer how the battery connects to your solar system. Ask what kind of inverter you have and how the battery will charge and discharge. Ask if the battery will work when the grid goes down. A good installer should be able to explain this clearly.

If you’re interested in learning a bit more about the importance of monitoring and programming your energy, you might want to check out the following article titled, What is Consumption Monitoring?

Get started with solar. click here.

Mistake 5: Not Knowing the Difference Between Single-phase and Three-phase Backup

Some people think their battery will keep the whole house running during a blackout. That is not always the case. What your battery can power depends on how your home is wired and how your backup is set up.

Most Australian homes are connected to the grid as a single-phase or a three-phase site.

A single-phase battery usually powers the whole home. This includes lights, the fridge, power points…everything.

A three-phase battery can cover more of the home but needs special planning and the right equipment. It also costs more.

If you have a three-phase home but only install a single-phase battery, you will only get power on one phase during a blackout. That means some parts of your home will still go dark, even though you have a battery.

For example, a family had a three-phase home but installed a single-phase battery with limited backup. During a blackout, only one part of the house worked. The kitchen lights stayed on, but the heating and the garage door did not. They were surprised and upset because no one had explained the setup clearly.

Tip: Ask your installer if your home is single-phase or three-phase. Then ask what kind of backup the battery will provide. Make sure it matches your needs. If you want more of the house powered during a blackout, you may need a three-phase backup system and a larger battery.

If you’re interested in learning a bit more about installing a single-phase battery like the Powerwall 3 on a three-phase site, you might want to check out the following article titled, Can I Install a Single-Phase Battery on a Three-Phase Home?

Let’s go solar today.

Mistake 6: Choosing the Wrong Installer

The installer you choose can make or break your battery system. A good battery with a bad installation will not work well. You could lose power, waste energy, or face expensive repairs. Some people end up with systems that are not safe or do not meet local rules.

Not all installers have the same level of training or care. Some rush through jobs or leave out key parts. Others do not take the time to explain how the system works. If they do not test the setup correctly, you might not notice a problem until the power goes out.

For example, one couple hired the cheapest installer they could find. The system worked at first, but during a blackout, it failed. Fixing it cost them more than choosing a better installer from the start.

Tip: Always check if the installer is accredited by Clean Energy Council (CEC). Look at reviews from other customers. Ask how many battery systems they have installed before. Make sure they explain the whole setup to you and answer your questions clearly.

If you’re interested in learning a bit more about the importance of a good installer for your solar (the most important component of any system, seriously), you might want to check out the following article titled, In-house Installers vs. Subcontractors: Which is Better?

Shine brighter with solar.

Mistake 7: Ignoring the Warranty and Support

A solar battery is a significant investment. You need to know what happens if something goes wrong. Some people do not read the warranty or ask about support. Later, when their battery has a problem, they find out it is not covered or that help is hard to get.

Warranties can be tricky. Some only cover the battery for a few years. Others might cover the battery for ten years, but only if you follow certain rules. Some warranties are handled locally, and some are managed overseas. This makes a big difference if you need a fast repair or replacement.

For example, one homeowner bought a battery online from a company overseas. When it stopped working, no one in Australia could fix it because the installer went out of business. There was no one to fulfil the warranty. He bought a second battery just to keep power in his home.

Tip: Ask how long the battery warranty lasts. Ask what it covers and who to call if there is a problem. Check if the company has support staff in Australia. Choose a product with strong local support and a clear warranty.

If you’re interested in learning a bit more about the warranties for the products we install, you might want to check out the following article titled, A Complete Guide to Solar Warranties.

Time to switch to solar?

Wrapping It All Up

Buying a solar battery is a smart step, but only if you get the right one for your needs. It is easy to make mistakes when the details feel confusing or the sales talk sounds convincing. But now you know what to look out for.

• Do not buy a battery that is too big or too small for your home.
• Think about how your energy use might grow over time.
• Make sure your battery matches your solar system and can run what you need during a blackout.
• Choose an installer who knows what they’re doing.
• And always check the warranty and support.

A good solar battery should save you money, give you peace of mind, and make your solar panels even more useful. When you avoid these mistakes, you make that much more likely.

At PSC Energy, we help customers learn about solar batteries with consultations for customised solar systems. Take your time. Ask us the right questions. And we’ll plan it together for today and tomorrow.

If you’d like to learn a bit more about SigenStor from Sigenergy, you might want to check out the following article titled, Sigenergy SigenStor Quietly Becomes Australia’s Top Solar Battery Brand.

Now you know how batteries save you money, we can answer the $10,000 question…

Are Solar Batteries Worth It?

On a flat tariff — not so much.

As you can see in the table above – a 14.5 year payback with a Powerwall on a flat tariff is typical. In my experience, that’s too long for most, although you can improve your payback by getting a rebate, joining a VPP, optimising your tariff or buying a cheaper battery (but don’t go too cheap).

But on a time-of-use tariff, it’s much better.

If you are on a time-of-use tariff and can get a 6-7 year payback, home energy storage starts to look like a good investment — especially if you value any of these bonus reasons for investing in a battery:

• Protection from blackouts
• Being green (by supporting a more renewable grid)
• Revenge (you hate energy companies)
• Love (you love owning the latest tech)

I’ve written a detailed answer to ‘Are Solar Batteries Worth It?‘, which considers where you live, what tariff you are on, and what local VPPs are available to you.

Am I Eligible for Battery Rebates?

Battery rebates make batteries cheaper, improving payback.

National Battery Rebates?

An Australia wide federal battery rebate lowers home battery costs by around $330 per kilowatt-hour (kWh) of usable capacity. 

State/Territory Rebates?

The federal battery rebate to be compatible with state and territory rebates. Currently, WA is the only state that offers a rebate.

• Western Australia’s Residential Battery Scheme is worth up to $130 per kWh for up to 10 kWh of storage capacity, or $380 in regional WA. You are required to join a VPP.

Subsidised Battery Loans

Are you interested in learning more about Wall Mounted Battery(hu,it,vi)? Contact us today to secure an expert consultation!

• ACT offers an interest-free $15,000.
• WA will offer interest-free loans of up to $10,000 as part of its Residential Battery Scheme.

Find out more about how these rebates and loans work on our in-depth Battery Rebates page.

VPP Rebates

Local government subsidies aren’t the only way to get a cheaper battery. Some virtual power plants give you an upfront discount on a new battery:

The downside is you lose control of your battery, and it is is worked harder — which can shorten its lifespan.

Nerd Fact: A Virtual Power Plant (VPP) is a collection of internet-connected residential batteries controlled by an energy company. This army of batteries charge and discharge in unison to support the grid.

Pro-tip: My Virtual Power Plant comparison table details every VPP available in the country.

I’ve been talking a lot about costs and returns, but let’s not lose sight of another massive perk — resilience. In an age of wild weather and unpredictable blackouts, a solar battery can be your home’s safety net, keeping the lights on when the grid throws in the towel.

You’ll be surprised to learn that not all batteries come with backup, and not all backup is equal. Here’s what you need to know if blackout protection is important to you…

Pro-Tip: The New South Wales Government has an additional VPP incentive of $55 per kWh of battery storage up to 10 kWh. This VPP incentive is what remains of the NSW battery rebate that got scrapped.

Which Battery Systems Protect Against Blackouts?

Most solar batteries available in Australia promise to keep you powered up during a blackout. But not all are created equal. Here are the must-know features that could make or break your blackout resilience:

• Backup Current: Measures how many gadgets and appliances you can keep running simultaneously.
• Surge Current: Check if the battery can handle the initial power spike when you start up an appliance.
• Switchover Time: The momentary blackout you’ll experience when switching from grid to battery — this can range from milliseconds to a few minutes.
• Solar Charging Without the Grid: Some systems cut off your solar charging capabilities when the grid’s down — watch out for this.
• Failsafe Design: If the battery’s inverter goes kaput, will it mess with your regular grid supply?

An experienced installer is your best mate in navigating these intricacies. And remember, if you’re eyeing a budget battery, scrutinising these features is even more crucial.

Pro-tip: Some cheaper battery systems can interrupt the grid power to your essential circuits if the inverter hardware fails. Always install a $100 battery bypass switch to override it and keep the lights on if there’s a problem.

Whole Home Backup

Buying a battery system to back up an entire Australian home costs big dollars. I recommend saving thousands by choosing a handful of essential circuits and backing those up. For example:

• Fridge (no one likes spoiled food)
• Lights (for obvious reasons)
• A few sockets, including one for your internet router (stay connected)
• Small air conditioner (because our summers are no joke)

By zeroing in on these essentials, you’ll get the most bang for your buck and still keep things civilised when the grid goes down.

Why Are Lithium-ion Batteries Best?

Wondering why Lithium-ion is the go-to for solar batteries? Let’s delve into that next.

Almost all grid-connected solar batteries in Australia are lithium-ion because they:

✅ store more energy by weight and volume

✅ are higher power by weight and volume (can charge and discharge faster)

✅ are more efficient – typically only losing 10% of energy when charged and then discharged

✅ are maintenance-free

✅ last longer than older lead-acid battery technology

✅ don’t require excessive amounts of space, fitting easily into most homes

The biggest disadvantage of Lithium-ion batteries is:

❌ in the unlikely event they catch fire, they burn like hell

Types Of Lithium-ion Solar Battery

Unless you want to go mega niche, you can choose from 3 types of  solar batteries (all sub-types of lithium-ion):

• NMC
• LFP
• LTO

Insider-tip: The Powerwall 2 is an NMC battery, but the Tesla Powerwall 3 has LFP battery cells and an integrated 11.3kW solar inverter – making it a true all-in-one battery system (see below).

What Will A Solar Battery Look Like On My Home?

Your solar battery’s aesthetics will depend on whether it is:

• an all-in-one system
• a separate battery and inverter
• a Powerwall 2 (which is a mixture of the above)

All-In-One Battery Systems

An all-in-one solar battery system contains almost everything you need in one big box:

• battery
• battery inverter
• solar inverter
• backup switchover

In the marketing materials, you’ll see them with zero wires attached. Reality is not as neat:

Separate Battery & Inverter

A separate battery and battery inverter won’t look as tidy as a well-installed all-in-one, but a good installer can keep everything neat:

Tesla Powerwall 2

The Powerwall 2 is almost an all-in-one. The big white Tesla box contains the battery and battery inverter. But it also needs a smaller ‘gateway box’, and your solar panels need a separate solar inverter. A good installer can make it look neat, but not quite as neat as the marketers want you to believe:

Alright, so you’ve got a mental picture of your future solar battery. The next step? Figuring out where this beast can live in your home. Keep in mind, Australia’s got some of the toughest rules globally when it comes to placement.

Powerwall 3

The new Powerwall 3 is almost all-in-one. It has a built-in solar inverter, so you can plug up to 20 kW of solar panels into it. However, it still needs the same Gateway box as the Powerwall 2 to handle backup and monitoring. Powerwall 3 is a good choice if you are buying your battery and solar array at the same time.

Modular Batteries

Modular batteries are stackable or connectable units that you can add to over time as your energy needs grow. Unlike monolithic systems like the Powerwall 3, which come in one fixed size, modular batteries are designed to be lightweight, compact, and easier to install.

These batteries don’t just perform well — they look good too. Most resemble sleek building blocks that can stack vertically or connect horizontally, depending on the design. Popular modular battery brands include BYD or Sigenergy.

Where Should I Install My Solar Battery?

Australia has strict standards for how and where batteries are installed – specifically Australian Standard AS. You don’t need to understand the electrical details, that’s the sparky’s job – but you do need to know how it affects where you can put it.

For example, places you can’t put a battery include:

• within 600mm of a window
• under the floor of a habitable room
• on a wall shared with a habitable room without a ‘non-combustible’ barrier

And you definitely can’t put one in your dining room, like some battery brochures would have you believe:

Does It Matter Where I Live?

Australia’s a big country, and where you live can factor into which battery is best for you…

Climate

The closer you live to Melbourne or Hobart, the lower your annual solar production, so you’ll need a larger solar system to reliably charge a battery all year.

At the other extreme, heat is the #1 thing that will shorten your battery’s life. So keep it cool if you live in a particularly sunburnt part of Australia, and check its ambient temperature range in the battery comparison table at the top of this page before buying.

Electricity Tariffs

‘Solar sponge’ electricity plans, which can boost battery payback, and allow you to charge cheaply from the grid on low solar days are currently only available in WA, SA and QLD.  But they’re likely to appear in other states soon.

Rebates/subsidies/VPPs

Certain government battery rebates, interest-free loans, or Virtual Power Plants are area-specific.

Grid Connection Rules Around Battery Inverters

Some local DNSPs (Distributed Network Service Providers), like Essential Energy, still make it hard to add a battery inverter if you already have a solar inverter. A good local installer will be all over these rules.

Watch A Professional Solar Battery Installation

Installing a solar battery isn’t just a matter of connecting a few wires and it usually takes two people one day. It’s a precise job that requires planning, compliance with Australian standards, and a licensed electrician. Whether you’re upgrading your current solar setup or going hybrid, the goal is to keep your home running smoothly — even during a grid outage.

The battery is mounted securely (on the wall or floor) and connected to an inverter — either your existing hybrid one or a new battery inverter. The key is seamless integration with your solar panels and grid for maximum safety and performance.

Want to see how it’s done? Watch the video below for a behind-the-scenes look at a professional installation, from setup to final handover.

Solar & Battery Calculator

My solar & battery calculator estimates the savings and payback of solar and batteries for your situation. Crucially, it separates out the solar and the battery savings, so you can decide if home energy storage is worth the extra dollars.

Add a Battery Calculator

If you already own a solar panel system but want to calculate the potential savings of adding a battery, you can use my “Add a battery” calculator.

Battery Reviews

Read expert solar battery reviews and browse customer reviews for most battery brands sold in Australia.

Hybrid Inverter Comparison Table

Installing a hybrid inverter to control both your solar panels and your solar battery can save you money because you only need one expensive (~$) inverter. Here is a table comparing all hybrid inverters we know of available in Australia. If you choose one of these for your solar installation, adding batteries can be cheaper and easier in the future.

Battery 101 Guides

Understanding Batteries 101: This is a more in-depth guide aimed at technical understanding of home batteries, delving into how they work and comparing different technologies like lead-acid and lithium-ion. It also explains the difference between power and energy in the context of batteries and discusses integrating a battery with a solar system using AC or DC coupling.

Buying Batteries 101: If you are serious about buying a solar battery – you should read this guide (or watch the video) so you can go toe to toe with any salesperson and get the right battery system at the right price.

Owning Batteries 101: Once your solar battery is installed, here’s what you need to know for a decade or two of cheap, secure power.

FAQs

Glossary

Battery Comparison Table Rows

Price: Our best retail price estimate includes GST. For the required hardware only.

Battery Type: Either LFP, NMC or LTO. See here for an explanation of the differences.

All-in-one-unit: See here for a pictorial explanation of the difference between an all-in-one, a separate battery and inverter and a Powerwall.

Nominal Storage: How many kWh a battery can store in theory. In practice, most won’t let you use all their energy capacity in order to prolong their lifespan.

Usable Storage Capacity: How many kWh you can store in a battery in practice.

Power (kW): The speed at which a battery can charge and discharge. Check yours doesn’t limit this in backup mode.

Round Trip Efficiency: When you put a kWh in, how much do you get back out? Typically 90%.

Ambient temperature range: What air temperature is the battery rated for? If it gets too cold or too hot, performance can take a hit, or the warranty can be reduced, or both.

Off-grid capable: Does the manufacturer warrant the battery for off-grid?

IP Rating: How well sealed from the elements is the battery? Can it go outside?

Compatible Hybrid Inverters: A hybrid inverter is required for some battery systems – these are compatible ones. A hybrid inverter can also manage your solar panels – potentially saving a couple of thousand bucks.

Warranty: the headline warranty – before caveats. Sometimes this is shortened depending on how hard you work the battery.

Battery capacity remaining at end of warranty:This is how much of the original capacity you can pull from the battery under warranty. For example, a 10kWh battery that warrants 70% capacity at the end of 10 years would give you 7kWh.

Warranty length (1 cycle per day): How long is the warranty if you fully discharge the battery every day? Those on a flat tariff rarely cycle theirs more than once per day.

Warranty length (1.5 cycles per day): If you fully discharge the battery 1.5 times every day, how long is the warranty? This is typical for time-of-use tariffs where you charge during the day to get through the evening peak, and then again at night to get through the morning peak.

Cost Per Warranted kWh: 1 Cycle Per Day: If the battery cycles once per day, this is how much each warranted kilowatt-hour of stored electricity will cost. It exposes good and bad warranties.

Modern Slavery/Forced Labour:  Does the manufacturer have policies addressing modern slavery/forced labour risks.

Home Battery Quotes

If you’re ready to buy a solar battery, I can help you get quotes for quality home energy storage systems from pre-vetted installers quickly and easily:

Contact us to discuss your requirements of Lithium Battery Module. Our experienced sales team can help you identify the options that best suit your needs.