Power outages are stressful. They cut off your lights, fridge, heating, Wi-Fi, and anything else that keeps your home running. If you’ve dealt with one before, you know how quickly things fall apart when the power goes out.
Enter the solar battery.
At PSC Energy, we understand how frustrating it is to read spec sheet after spec sheet and still not know which battery will do the job. Every brand says they’re the best. But you need facts, not sales talk. We’ll guide you to the battery that turns on fast, powers the things that matter, and lasts long enough to make a difference.
In this article, you’ll learn about the following:
- What Makes a Solar Battery Great in a Blackout?
- Tesla Powerwall 3: Blackout Performance and Key Features
- Sigenergy SigenStor: Blackout Performance and Key Features
- Enphase IQ Battery 5P: Blackout Performance and Key Features
- Which Solar Battery Should You Buy?
- FAQ: Solar Batteries and Blackouts
By the end of this article, you’ll know what really makes a battery strong in a blackout. And by the end, you’ll have a clear idea of which one fits your home and your needs.
What Makes a Solar Battery Great in a Blackout?
Not all batteries work the same when the grid goes down. We install three that offer blackout protection: Tesla Powerwall 3, Sigenergy SigenStor, and the Enphase IQ Battery 5P. All perform exceptionally in a blackout, and we’ll dive into each shortly.
Here are the key things that make a battery reliable during a blackout.
Usable Capacity (kWh)
This is how much energy the battery can use. It’s measured in kilowatt-hours (kWh). The higher the number, the more devices you can run and the longer your backup energy will last.
Example: If your battery has 10 kWh of usable capacity, and your home uses 2 kWh per hour, it will last about 5 hours.
Power Output (kW)
This tells you how much power the battery can deliver at once. It’s measured in kilowatts (kW). A higher number means the battery can run more appliances at the same time, or power energy-hungry devices like your air conditioner or oven.
A battery with low output might only run lights and a fridge. A higher-output battery could run your whole house.
Response Time
This is how fast the battery turns on when the grid goes down. Some batteries switch instantly, so you won’t even notice the blackout. Others take a few seconds.
Instant response is best for sensitive equipment like computers or medical gear.
Expandability
Can you add more batteries later? Some systems let you stack or link batteries easily. Others need rewiring or new inverters to expand.
This matters if your energy needs might grow in the future.
Solar Compatibility
If you have solar panels or want to add them, your battery needs to work well with solar. Some batteries charge directly from your panels. Others need extra hardware.
Look for a battery that stores excess solar power and uses it during blackouts.
System Design (AC or DC Coupled)
- AC-coupled batteries are easier to install after solar panels are already in place.
- DC-coupled batteries are more efficient but may need a more complex setup for an entire energy system.
In blackout situations, ease of installation and reliability can be more important than small gains in efficiency.
Warranty and Lifespan
Most home batteries come with a 10-year warranty. Some also guarantee a certain number of charging cycles or a minimum capacity after a decade.
This tells you how long the battery will stay useful and when you might need to replace it.
If you’re interested in solar batteries, you might want to check out the following article titled, Are Solar Batteries Worth It in NSW? PSC’s Ultimate Guide for 2025.
Tesla Powerwall 3: Blackout Performance and Key Features
The Tesla Powerwall 3 is the latest version of Tesla’s home battery. It’s designed for both daily energy use and backup power. While the Tesla name is well-known, it’s important to consider how this battery performs when the grid goes down.
Usable Capacity
The Powerwall 3 has a usable capacity of 13.5 kilowatt-hours (kWh). This is enough to keep your essentials running for several hours or even a full day, depending on your energy use. For example, it could power a refrigerator, some lights, the internet, and a few small appliances for most of the day.
Power Output
The Powerwall 3 can deliver up to 11.5 kilowatts (kW) of continuous power when paired with solar. This level of output means it can run more appliances simultaneously, including heavy loads like an electric stove or an air conditioner, as long as your setup supports it.
Response Time
The Powerwall switches over to backup power almost instantly. It does this within milliseconds, so fast that most people don’t even notice the power has gone out. This helps protect sensitive electronics and keeps your home running without interruption.
Expandability
The Powerwall 3 is designed to be modular. You can install multiple units to increase your total storage and power output. This makes it a good fit for larger homes or homes with high energy needs.
However, because the Powerwall 3 has a built-in solar inverter, stacking more units will require careful planning with your installer.
Solar Compatibility
This version of the Powerwall comes with a built-in solar inverter, which simplifies installation for new solar systems.
But it’s less ideal for retrofitting existing systems, especially those that already have a third-party inverter. It’s optimised for new installations where the Powerwall can control the whole energy system.
System Design
The Powerwall 3 is a DC-coupled battery with an integrated inverter. This makes it highly efficient, especially when paired with new solar installations. It’s sleek, compact, and designed for indoor or outdoor installation.
Warranty and Lifespan
Tesla offers a 10-year warranty on the Powerwall. It guarantees that the battery will keep at least 70% of its original capacity after 10 years.
Tesla also has a strong track record for software updates and remote diagnostics, which can help keep the system running smoothly over time.
Strengths in a Blackout
- High power output lets you run more devices.
- Fast, seamless switchover.
- Large usable capacity.
- Strong software and monitoring tools.
Limitations to Consider
- Better for new solar systems than retrofits.
- Expanding can be more complex due to the built-in inverter and DNSP regulations.
- It lacks three-phase backup.
The Tesla Powerwall 3 is a powerful, reliable option for blackout protection, especially if you’re building a new solar setup or want to back up your whole home.
If you’re interested in learning a bit more about Tesla’s Powerwall, you might want to check out the following article titled, Pros and Cons of Tesla Powerwall 3: Everything to Know Before You Buy.
Sigenergy SigenStor: Blackout Performance and Key Features
The Sigenergy SigenStor is a newer entry to the home solar battery market, offering an all-in-one design and strong performance.
It combines a battery, a hybrid inverter, an EV charger, and an energy management system in one unit. While it’s not as well-known as Tesla, its blackout performance is solid and worth a closer look.
Usable Capacity
The SigenStor is modular and starts at 8 kWh per battery pack. You can stack up to 6 packs in one tower, giving you 48 kWh of usable capacity in a single unit.
This makes it very flexible. Smaller homes can start with one or two units. Larger homes can scale up to handle longer outages or higher usage.
Power Output
This depends on the inverter, as Sigenergy offers a variety, and each can handle a different power output. It can range relatively high, like 22.5kW. That’s more than both the Powerwall 3 and the Enphase 5P.
This means it can run large loads, such as air conditioners, electric vehicle chargers, and multiple appliances, at once. It’s strong enough for whole-home backup at three-phase sites.
Response Time
The SigenStor has an automatic switchover feature that kicks in almost instantly during a blackout. It’s fast enough that you won’t notice a pause, which helps protect your electronics and keeps things running smoothly.
Expandability
This system is highly expandable. You can add more battery packs at any time, and stack them vertically in the same tower. For even more storage, you can install multiple towers. The modular design makes it easy to scale as your needs change.
Solar Compatibility
The SigenStor is a hybrid system, meaning it works with both DC and AC solar inputs. It can connect directly to your solar panels, without the need for a separate inverter. This flexibility makes it a strong choice for both new and retrofit solar installations.
System Design
The all-in-one design combines the battery, inverter, and control system into a single stackable unit. It’s a DC-coupled system but with added compatibility for AC systems.
It supports EV charging with an optional charger. It integrates with a home energy management system that can shift loads or schedule power use.
Warranty and Lifespan
Sigenergy offers a 10-year warranty for its batteries. The expected lifespan is over 6,000 cycles, which is higher than average.
This means the battery can charge and discharge daily for many years without significant degradation. It also guarantees 70% capacity after 10 years, similar to Tesla.
Strengths in a Blackout
- High-power output for large loads.
- Scalable capacity up to 48 kWh per tower.
- Instant switchover keeps appliances running.
- Works well with solar, new or existing.
- Optional built-in EV charger block and energy controls.
Limitations to Consider
- Newer brand with untested market history.
- Popularity has led to stock shortages across Australia.
The SigenStor is a strong, flexible option for blackout protection. It’s ideal if you want full-home backup and room to grow. While it’s less known than Tesla, its performance specs make it a serious contender.
If you’d like to learn a bit more about Sigenergy’s SigenStor, you might want to check out the following article titled, Pros and Cons of the Sigenergy SigenStor Solar Battery and Energy System.
Enphase IQ Battery 5P: Blackout Performance and Key Features
The Enphase IQ Battery 5P is a modular battery system built for flexibility and reliability. It’s part of Enphase’s larger microinverter ecosystem, which many homes already use with their solar panels. While the 5P isn’t the biggest battery on the market, it has smart features that make it a good option for targeted backup and solar pairing.
Usable Capacity
Each Enphase IQ Battery 5P unit holds 5 kWh of usable energy. You can stack multiple units together to increase your total storage. For example, pairing three units gives you 15 kWh of usable capacity. This setup works well if you want to start small and grow over time.
Power Output
Each 5P unit provides 3.84 kW of continuous power and 7.68 kW at peak. That means a single battery can handle some big loads for short periods, but is better suited for light to moderate usage over time.
If you add more units, your available output increases. Two batteries, for example, can deliver 7.68 kW continuously.
Response Time
The 5P responds to outages in under a second. It’s not quite instant, but it’s fast enough that most people won’t notice. Your critical appliances will stay on, and your solar system (if paired) will keep generating power.
Expandability
This system is highly modular. You can add more units at any time. It’s a plug-and-play design, so installers can expand it without having to redo your whole system. This makes it easy to customise your storage over time, based on your needs and budget.
Solar Compatibility
The IQ Battery 5P is designed to work with Enphase microinverters. If your solar system already uses Enphase equipment, this battery connects easily.
It charges from solar, manages loads efficiently, and allows for solar generation during outages. If you don’t have Enphase solar yet, adding both together creates a seamless setup.
System Design
The Enphase system is AC-coupled. This means it connects to your home’s existing electrical panel and works well for retrofits.
Each battery has its own built-in microinverters that handle charging and discharging the battery. This design improves safety, allows energy to flow even if one unit fails, and supports more flexible installation options.
Additionally, the six built-in microinverters are easy to replace. Because there are six of them, they keep working when one goes down. This design allows the battery to keep operating even if one of the microinverters fails.
Other batteries, like the Powerwall, have only one inverter. It’s a central point of failure that can stop your solar battery from working.
Warranty and Lifespan
Enphase offers a 15-year warranty on the 5P, which is longer than other solar batteries in its class. It’s rated for over 6,000 cycles and is expected to keep 60% of its capacity after 15 years.
This provides long-term peace of mind and adds significant value to the investment.
Strengths in a Blackout
- Easy to expand.
- Strong warranty and long lifespan.
- Works well with existing Enphase solar systems.
- Supports solar use during blackouts.
- Safe, efficient microinverter design.
Limitations to Consider
- Lower output per unit compared to Powerwall or SigenStor.
- Best suited for partial backup unless you install multiple units.
- Performance depends on having or choosing Enphase solar components, such as a microinverter system.
The Enphase IQ Battery 5P is a solid choice for homes with Enphase solar systems or for those who want modular, flexible backup. While it may not power your whole house with a single unit, it can be scaled to meet most needs, especially when paired with solar.
If you’re interested in learning a bit more about IQ Batteries from Enphase, you might want to check out the following article titled, Pros and Cons of the Enphase IQ Battery 5P Solar Battery.
Which Solar Battery Should You Buy?
Feature: Usable Capacity
- Tesla Powerwall 3: 13.5 kWh
- Sigenergy SigenStor: 8 kWh (modular and stackable)
- Enphase IQ Battery 5P: 5 kWh (modular and stackable)
Feature: Max Continuous Power Output
- Tesla Powerwall 3: 11.5 kW (when paired with solar)
- Sigenergy SigenStor: Depends on the custom inverter.
- Enphase IQ Battery 5P: 3.84 kW
Feature: Peak Power Output
- Tesla Powerwall 3: Around 11.5 kW.
- Sigenergy SigenStor: Depends on the custom inverter.
- Enphase IQ Battery 5P: 7.68 kW per unit (short bursts).
Feature: Response Time
- Tesla Powerwall 3: Instant (milliseconds).
- Sigenergy SigenStor: Instant (milliseconds).
- Enphase IQ Battery 5P: Less than 1 second.
Feature: Expandability
- Tesla Powerwall 3: Yes, but it can be complex due to the integrated inverter.
- Sigenergy SigenStor: Yes, stack up to six blocks per tower (more with multiple towers).
- Enphase IQ Battery 5P: Yes, add as many units as needed.
Feature: Solar Compatibility
- Tesla Powerwall 3: Built-in inverter (DC-coupled), best for new solar installs.
- Sigenergy SigenStor: Works with both AC and DC solar.
- Enphase IQ Battery 5P: Best with Enphase microinverter solar systems (AC-coupled).
Feature: Retrofit Friendly
- Tesla Powerwall 3: Can be AC-coupled but has less value due to energy inefficiencies.
- Sigenergy SigenStor: Very flexible, works for new or existing systems.
- Enphase IQ Battery 5P: Very retrofit-friendly with Enphase systems.
Feature: System Design
- Tesla Powerwall 3: All-in-one, DC-coupled.
- Sigenergy SigenStor: Hybrid (DC/AC), stackable tower.
- Enphase IQ Battery 5P: AC-coupled with built-in microinverters.
Feature: EV Charger Integration
- Tesla Powerwall 3: No.
- Sigenergy SigenStor: Yes, EV charger is optional.
- Enphase IQ Battery 5P: No.
Feature: Warranty
- Tesla Powerwall 3: 10 years, 70% capacity guaranteed after 10 years.
- Sigenergy SigenStor: 10 years, 70% capacity after 10 years.
- Enphase IQ Battery 5P: 15 years, 60% capacity after 15 years.
Feature: Ideal For
- Tesla Powerwall 3: Whole-home backup for single-phase homes.
- Sigenergy SigenStor: High-performance backup (including true three-phase backup) with room to scale.
- Enphase IQ Battery 5P: Partial or complete backup with easy expansion.
Feature: Main Limitation
- Tesla Powerwall 3: Less value when AC-coupled for homes with existing solar and complicated installations on three-phase sites.
- Sigenergy SigenStor: New brand with untested warranty support.
- Enphase IQ Battery 5P: Lower output per unit, needs multiple units for larger loads.
If you’re interested in learning a bit more about the price of solar batteries, you might want to check out the following article titled, How Much Are Solar Batteries? A Full Breakdown of Prices, Rebates, and Value in 2025.
Rolling Blackout? I Just Roll to Backup
If you’re building a new solar-plus-battery setup and want high power, seamless integration, and smart features, the Powerwall 3 is a top contender. It delivers strong performance and is backed by a proven brand. Unfortunately, it only offers whole-home backup for single-phase sites.
If you need something powerful, scalable, and feature-rich (especially for whole-home backup on a three-phase site and high energy use), the Sigenergy SigenStor stands out. It’s newer to the market, but its flexibility and output make it a serious option.
If you prefer a safe, modular system that’s easy to expand and works well with existing Enphase systems, the Enphase IQ Battery 5P is a smart and reliable choice.
If you’re still unsure, talk to us at PSC Energy. We understand these systems inside and out. We’ll help you match the tech to your real-world needs, not just sell you what’s popular. It’s what we do.
If you’re interested in learning a bit more about solar and battery rebates in NSW, Australia, you might want to check out the following article titled, Ultimate Guide to Australia’s 2025 Solar Rebate and Battery Rebate: Federal and NSW Rebate for Solar.
FAQ: Solar Batteries and Blackouts
What makes a home solar battery good in a blackout?
A great blackout battery has high usable capacity, strong continuous power output, fast response time, solar compatibility during outages, simple expansion options, and a solid warranty. These traits keep lights, fridges, Wi-Fi, and key appliances running when the grid fails.
Does power output matter as much as capacity in a solar battery?
Yes. Capacity decides how long you can run. Power output decides what you can run at the same time. A higher continuous kW rating lets you run larger loads, such as air conditioners, ovens, or EV chargers, without tripping the system.
How fast do these solar batteries switch on when the power goes out?
Tesla Powerwall 3 and Sigenergy SigenStor switch over in milliseconds, so most people do not notice. Enphase IQ Battery 5P switches in under a second, which still keeps essentials on for most homes.
Will my solar panels keep working during a blackout?
Yes, with the proper setup. Powerwall 3, SigenStor, and Enphase 5P can form a microgrid so your solar can keep generating and charge the battery while the grid is down. Your installer must configure this during the design phase.
Which solar battery is best for a single-phase home?
All three work well on a single phase. Powerwall 3 offers high output in a single unit, which suits whole-home backup on single-phase systems. Enphase 5P offers modular units you can scale over time. SigenStor also supports strong single-phase performance with room to grow.
Which solar battery is best for a three-phase home?
SigenStor supports true three-phase backup, so it can keep all phases running in an outage. Powerwall 3 and Enphase 5P can support three-phase properties, but typically back up only one phase unless you use special designs. If you want full three-phase backup, choose SigenStor.
Which solar battery gives the most continuous power for large appliances?
Powerwall 3 delivers high continuous output per unit, which helps with big loads. SigenStor’s total output depends on the inverter size you select and can be very high when sized correctly. Enphase 5P delivers 3.84 kW per unit continuously and scales as you add units.
Can these solar batteries run air conditioning during a blackout?
Often, yes. You need enough continuous power and enough stored energy. A single split-system can be fine. Large ducted systems may require higher output or multiple batteries. Your installer will match the battery’s kW output to your HVAC’s start and run loads.
How long will a solar battery run in a blackout?
It depends on three things: how many kWh you have, how many kW you draw at once, and whether your solar can recharge during the day. Plan for essentials first. Add capacity if you want cooking, HVAC, and EV charging.
What is the difference between AC-coupled and DC-coupled solar batteries for blackouts?
AC-coupled is easier for retrofits and plays nicely with many existing systems. DC-coupled is more efficient in daily operation and is suited to new installs. For blackout reliability, both work well when designed correctly. Choose AC for simple add-ons. Choose DC for maximum efficiency in new builds.
Will my internet or devices reboot when the solar battery takes over?
With Powerwall 3 and SigenStor, the transfer is so fast that most routers and computers stay on. With Enphase 5P, sub-second transfers are still fast, but sensitive devices may reboot. A small UPS on your modem or workstation can remove any risk.
How do I size a solar battery system for whole-home backup?
List your must-run loads and their watts. Add your nice-to-have loads. Choose a battery or combination that meets both the kW you need at once and the kWh you need over time. Use solar recharging during the day to extend runtime.
How complex is installing a solar battery backup for blackouts?
New DC-coupled builds with Powerwall 3 or SigenStor are straightforward because the inverter is integrated. Enphase 5P retrofits are also simple because each unit has its own microinverters.
Can I choose which circuits get backup power with a solar battery?
Yes. Your installer creates a backup circuit list in a sub-board. Most homes include the fridge, lights, modem, key power points, and medical or work gear. Add HVAC or cooking only if your battery’s kW and kWh can support it.
Which solar battery monitoring apps work best in blackouts?
All three have strong apps. Powerwall has a polished app with clear state-of-charge and modes. Enphase Enlighten provides deep insight and works well with existing Enphase solar systems. SigenStor’s app adds smart controls and AI-optimised energy-shifting features. Each app shows battery level and solar status during an outage.
Do NSW and federal rebates apply to blackout-ready solar batteries?
Yes, if the product and installer are eligible. Rebates reduce upfront cost but do not change blackout performance. Check current program rules when you quote, because details can change.
