Buying a solar battery isn’t cheap. You want something that works, lasts a long time, and won’t leave you in the dark if it breaks.
That’s where the warranty comes in. But here’s the problem: most warranties are full of confusing words and hidden limits.
You’ve probably looked at Tesla, Enphase, or maybe even a newer brand like Sigenergy. And now you’re asking the right question: which one will last the longest?
In other words, which one has the best warranty?
At PSC Energy, we know what makes for a long-lasting solar battery. We know what to look out for and how it can help customers save money and do something good for the planet. The warranty is the best indicator of how long you can estimate a solar battery’s lifespan.
In this article, you’ll learn about the following:
- What Makes a Good Solar Battery Warranty?
- Tesla vs Enphase vs Sigenergy: Warranty Comparison
- What to Watch Out for in a Solar Battery Warranty
- So… Which Solar Battery Warranty Is the Best?
By the end of this article, you’ll learn what a good solar battery warranty really looks like. You’ll also see how Tesla, Enphase, and Sigenergy compare, and which one might work best for your home in Australia.
Let’s make this simple.
What Makes a Good Solar Battery Warranty?
A good warranty protects you. It should be easy to understand and not full of tricks. Here are the big things to look for:
Warranty Length: This is how long the company says they’ll fix or replace your battery if something goes wrong. Enphase offers 15 years, while Tesla and Sigenergy both offer 10 years.
Energy Use Limit (Throughput): Some warranties end early if you use the battery a lot. This is called a throughput limit. Think of it like a cap on how much energy the battery can move over its life.
Battery Power Promise (Capacity Guarantee): All batteries lose power over time. A good warranty promises that after 10 or 15 years, your battery will still hold most of its charge, usually around 70%. This means your solar battery might not hold quite as much energy, but it will still work.
Installer Rules: Most brands want a trained installer to set up the battery. If someone installs it wrong — or isn’t approved — the warranty might not count.
Can You Transfer It? If you sell your house, can the next owner use the warranty? Tesla, Enphase, and Sigenergy all say yes, but you may need to let them know.
Who Handles the Warranty? This is typically done through your installer. Make sure you know who to call if something breaks.
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.
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Tesla vs Enphase vs Sigenergy: Warranty Comparison
Let’s take a look at each brand first.
Tesla Powerwall: Tesla is a big name in Australia. The Powerwall has been around for years. It’s a 13.5 kWh battery. Tesla provides a 10-year warranty.
Enphase IQ Battery: Enphase is known for its microinverters, and their battery works well with their whole solar system. The Enphase IQ Battery is smaller, modular, and easy to expand. Enphase offers a 15-year warranty, which is the longest of the three.
Sigenergy SigenStor: Sigenergy is newer in the market. Their SigenStor battery is part of an all-in-one system that includes the battery, inverter, EV charger, and energy manager. It’s packed with features and backed by a 10-year warranty.
Now, here’s how they compare:
Solar Battery Warranty Comparison Table
| Feature | Powerwall | Enphase | SigenStor |
| Warranty Length | 10 years | 15 years | 10 years |
| Throughput Limit | 37.8MWh (13.5kWh unit) | 6,000 cycles (5kWh unit) | 32.84MWh (8kWh unit) |
| Capacity Guarantee | 70% after 10 years | 60% after 15 years | 70% after 10 years |
| Transferable? | Yes | Yes | Yes |
| Pro Installation? | Yes | Yes | Yes |
If you’d like to learn a bit more about the cost of SigenStor, we recommend you check out the following article titled, How Much Does the Sigenergy SigenStor Cost?
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What to Watch Out for in a Solar Battery Warranty
Solar battery warranties can be tricky. Even when they look great, there might be small rules that can ruin your coverage. When you know what to look for, it’s easier to spot a strong warranty and avoid one that looks good but doesn’t protect you well.
Here are the most important things to watch for when reading a warranty:
Usage Limits
Some warranties end early if you use your battery too much. This is called a throughput limit. Your warranty stops once you hit that number, even if you’re still within the number of years.
For example, if you use a lot of battery power every day, you might hit Tesla’s 37.8 MWh limit within 10 years. If that happens, the warranty is over.
Ask your installer how much energy you’ll likely use, and whether the battery can handle it without running out of warranty too soon.
Prorated Coverage
Some companies lower the amount they’ll cover over time. This is called a prorated warranty. This means that if your battery fails in year nine, you might only get part of the cost back.
None of the three brands here use prorated warranties, which is good. But it’s something to look for if you compare other batteries later.
Installer Rules
All three brands require professional installation. If someone installs it who isn’t approved or trained, your warranty might not count.
Some brands also need the installer to register or commission the battery. If they forget, your warranty might not be valid.
System Rules
Enphase batteries need to be part of an Enphase system to get full warranty support. If you try to use them with another brand’s system, the warranty might not apply.
Always check if the battery must be used with the brand’s inverter or app to stay covered.
Climate and Location
Some batteries have limits for temperature and weather. For example, if your battery is outside and not in a protected spot, it could lose its warranty.
Check the warranty for any rules about where you install the battery. Australia has a hot climate, so this can matter a lot.
Claim Process
Find out who you contact if something goes wrong. Is it the installer or the company? Ask how long it usually takes to get a battery fixed or replaced.
A good warranty is only helpful if the company makes it easy to use.
If you’d like to learn more about the price of a Powerwall 3, you might want to check out the following article titled, How Much Does a Tesla Powerwall 3 Cost?
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So… Which Solar Battery Warranty Is the Best?
Let’s keep it simple.
Want the longest coverage? Go with Enphase.
Enphase gives you 15 years of protection. That’s five years longer than Tesla or Sigenergy. It’s great if you want peace of mind for the long haul.
Want a safe, proven option? Go with Tesla.
Tesla’s been around for years and has a solid record. Their 10-year warranty is fair and easy to understand. If you want something that works and has support, Tesla is a smart choice.
Want cool features and an innovative system? Go with Sigenergy.
Sigenergy’s SigenStor is full of extras. It has an EV charger, inverter, and more. It also has a clear 10-year warranty. The brand is new, but they’re growing fast in Australia.
If you’re interested in learning a bit more about IQ Batteries, you might want to check out the following article titled, How Much Does an Enphase IQ Battery 5P Cost?
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Before You Buy: Final Tips
Here are a few things to do before making your final choice.
Ask your installer to explain the warranty: Don’t be afraid to ask questions. If something isn’t clear, get answers before you buy.
Check the energy use limit: Make sure the battery will last for the full warranty period based on how much power you use.
Make sure the right person installs it: Only use certified installers. This keeps your warranty safe.
Use the battery like the brand says: Stick to the right system setup. Don’t try to mix brands if the warranty says not to.
Keep your documents: Save your warranty, receipt, and installer info in one place. You’ll need it if something breaks.
Know who to call: Ask who handles the warranty. Some issues go through the installer, others through the battery company.
For a conversation that will answer all these questions, contact PSC Energy. We’re installing batteries by the dozen now that the federal government has landed. We’ll talk you through your options and help you find a battery that’s a good fit for you. It’s what we do.
If you’re interested in learning a bit more about the federal solar rebate, also known as the Federal Cheaper Home Batteries Program, you might want to check out the following article titled, What the 2025 Federal Election and the Government Rebate Means for Solar Batteries in Australia.
