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The best home battery and backup systems: Expert tested
As someone who experiences regular power outages, I've learned that having a backup plan for electric outages is a must for surviving everyday life. While you can always use an air-cooled home generator powered by gasoline or propane, or a more expensive liquid-cooled generator, backup power from a battery system can provide a renewable source of power, especially when you connect your battery storage system to a solar panel system.
Also: Battery backup vs standby generators
Not to mention, a set of backup batteries, which can be either dry or wet, offers a long-term solution to power outages. Dry batteries, such as lithium-ion batteries, do not work well in extreme temperatures, while wet batteries use a liquid electrolyte to generate electricity, with lead-acid batteries being a popular choice.
What is the best home battery and backup system right now?
Our top pick for the best home battery and backup system goes to the Tesla Powerall + due to its 10-year warranty, great power distribution, and energy capacity of 13.5kWh. However, since the Tesla Powerall + is quite expensive and different systems may fit your needs better than others, we've included a variety of picks to fit all types of needs and budgets.
The best home battery and backup systems of 2024
- 10-year warranty
- Stack up to 10
- Dedicated app for power management
- Great power distribution
- Very expensive
- Only compatible with Tesla-branded solar panels
Tesla Powerwall + features: Capacity: 13.5kWh (kilowatt-hour) | Power source: Solar panels | Controls: Dedicated app | Multi-unit configurations: Yes
The Tesla Powerwall is a leading battery backup system that simplifies your switch to backup battery power. With the ability to recharge using solar PV panels, you can rely on stored solar energy during power outages.
The Powerwall + provides an energy capacity of 13.5kWh and a power rating of 7.6kW, delivering continuous power of 5.8kW in the absence of sunlight. It comes with a ten-year guarantee and can be monitored and managed through its app. However, you can only purchase a Powerwall if you also buy Tesla's solar panels.
Also: The best home EV chargers you can buy, according to experts
To ensure you have the right-sized backup batteries for your home, you can connect up to 10 Powerwalls. It's recommended to use the Tesla Powerwall with a solar panel system for optimal results. Additionally, some states, such as WA (22%), offer a Federal Solar Investment Tax Credit to help with costs. The long-running PBS home improvement show This Old House strongly encourages customers considering the Tesla Powerwall+ to take advantage of all local, state, and federal tax incentives to help reduce the cost of installation.
One Reddit user said that it's a "game-changer for continuous power," and that it's well worth it if you want backup during outages or to store excess solar energy.
- Expandable to up to 90kWh
- Seamless 20ms transfer
- Consumption insights in EcoFlow app
- Heavy for transporting at 186 lbs
- Can become an expensive solution
EcoFlow Delta Pro Ultra + Smart home panel 2 features: Capacity: 6kWh (kilowatt-hour) | Power source: Grid, solar panels, generators | Controls: EcoFlow app | Multi-unit configurations: Yes
The Delta Pro Ultra is EcoFlow's latest portable battery unit. Its true beauty lies in combination with the new EcoFlow Smart Home Panel 2 to become a seamless whole-home backup solution. The DPU is a combination inverter and battery, and the system is expandable from 6kWh to 90kWh capacity. Each Smart Home Panel 2 can support up to three inverters, while each inverter can handle up to five stackable batteries.
Review: The EcoFlow Delta Pro Ultra is the home backup system we needed during a recent storm
Even without the expanded storage capacity, a single EcoFlow DPU can provide essential power for a home for up to two days. ZDNET writer Maria Diaz went hands-on with the DPU and Smart Home Panel 2 and said that it provides a seamless transfer from grid to backup power in the event of a power outage.
"The last outage I experienced lasted two days and coincided with this winter's coldest week," Diaz wrote. "Delta Pro Ultra gave my family power so our kids could eat warm meals (albeit microwaved), sleep with their night lights and sound machines, and keep essential devices charged."
The Delta Pro Ultra is also portable and capable of being transported to campsites, with an RV, or remote locations. Its LFP battery means you can even bring it inside to run appliances or charge devices in a pinch without worrying about emissions. However, one Reddit user who purchased the DPU said the solar asepct is good enough for top-off, but not enough to be 100% off grid reliant.
- Modular design
- Intuitive app and control unit
- 10-year warranty
- Works with most solar panels
- Very, very expensive
- Price doesn't include solar panels or installation
Generac PWRcell features: Capacity: Up to 36kWh | Power source: Solar panels | Controls: Dedicated app and control unit | Multi-unit configurations: Yes
The Generac PWRcell system offers 9kWh of storage capacity through three Lithium Ion battery modules, each rated at 3.0kWh. The system includes an inverter and a battery storage cabinet, making it a comprehensive solution for backup power needs.
One advantage of the PWRcell is its compatibility with solar panels from various manufacturers, ensuring flexibility and avoiding vendor lock-in. Its modular design allows you to expand your storage capacity in increments of 3kWh up to 36kWh. It also comes with a ten-year limited guarantee and can be easily managed and monitored through its app.
Verified customers who have installed the Generac PWRcell praise the company's ability to reset the system over the phone (no all-day wait for a technician to show up), as well as the ability to check usage rates and system health via the companion app.
- Perfect for most homes
- Automatic remote updates
- Great warranty
- Extended warranty costs extra
Enphase IQ Battery 10T features: Capacity: 10.08kWh | Power source: Solar panels | Controls: Dedicated app | Multi-unit configurations: Yes
The Enphase IQ Battery 10T offers a high-energy capacity of 10.5kWh and delivers 5.76kVA at peak output. It consists of three base Encharge 3T storage units, which use Lithium Ferrous Phosphate (LFP) batteries with a power rating of 3.84KW.
This battery storage system cools passively, with no moving parts or fans, ensuring silent operation. Additionally, it comes with a ten-year limited warranty and a mobile app that allows for easy monitoring and control. Professional installation is necessary for this battery storage system.
Customers who have purchased and installed the Enphase IQ Battery 10T caution other buyers to check the exact dimensions of the units you're considering to see if they'll fit on your home. This is because Enphase partnered with several battery cell suppliers to help prevent supply chain disruptions, so the 10T may be available in different sizes.
What is the best home battery backup system?
In my opinion, the Tesla Powerwall+ stands out as the best option for a whole-home battery backup system. With a capacity of 13.5kWh, it offers plenty of energy storage to get you through power outages. The 10-year warranty also provides peace of mind that the product is built to last. The companion app is user-friendly and allows for easy monitoring and management of energy distribution and usage. Plus, the ability to connect up to 10 Powerwall+ units makes it a highly adaptable choice for changing energy needs.
| Home battery | Price | Where to Buy | Warranty | Capacity | Power Source Controls | Multi-Unit Configurations |
| Tesla Powerwall + | $12000 | Tesla website | 10 years | 13.5kWh | Dedicated app | Yes, up to 10 |
| EcoFlow DPU + Smart Home Panel 2 | $5800 | EcoFlow website, Amazon | 5 years | 6kWh | Dedicated app | Yes, up to 90kWh |
| Generac PWRcell | $18000 | Generac website | 10 years | Up to 36kWh | Dedicated app/control | Yes |
| Enphase IQ Battery 10T | $6200 | Enphase website | 10 years | 10.08kWh | Dedicated app | Yes |
Note: Prices are approximate and may vary depending on location, installation, and other factors.
Which battery backup system is right for you?
You'll need to determine the wattage and voltage consumption of your entire household. Thankfully, Lowe's has a handy worksheet to help you figure out your power needs. Once you know how many watts and volts your appliances use, you'll want to add at least 20% to the total; that way, if you add electronics or appliances, or something that starts to draw more power than usual, your system will be able to keep up.
And if retail and installation pricing seems a bit steep, many places offer some payment plan so you can break the final cost into more affordable monthly payments.
| Buy this home battery backup... | If you need... |
| Tesla Powerwall+ | A well-rounded and expandable home battery backup |
| EcoFlow DPU + Smart Home Panel 2 | A portable battery that can function as your whole-home backup solution |
| Generac PWRcell | A home battery backup system that's compatible with third-party solar panels |
| Enphase IQ | A compact battery backup system for smaller homes |
What should I look for in a home battery and backup system?
When choosing which home battery backup systems to include, we considered the following key factors:
- Technical Specifications: We considered technical factors such as peak, start, running voltage, and amperage. These permanent installations must be capable of handling the electrical load of all the appliances in the house on a daily basis.
- Capacity and Power: When choosing a system, it is important to consider the current capacity and power of your home in order to determine the appropriate battery backup system you will need. Choosing a system with inadequate capacity can cause electrical wiring problems. Selecting a system with excess capacity not only ensures smooth operation but also allows for future expansion as power needs change.
- Cost: Battery backup systems can be quite expensive, which is why it is important to consider pricing and installation costs. We compared different options to ensure you were getting the best value for your investment.
- Reliability: We took into account the reputation and reliability of the brands offering home battery backup systems, by researching customer reviews, performance track records, and overall reputations of manufacturers.
How did we choose these home battery backup systems?
While researching and testing each home battery backup system on this list, I and other ZDNET experts kept these criteria in mind:
- Scalability: No two households will have the same power needs. Each system on this list has been verified to allow for some degree of unit stacking and system scalability to allow customers to create custom, off-grid power solutions.
- Tax incentives: Local, state, and federal policies may offer some form of tax rebate or incentive for installing a solar-powered, battery backup system. These help reduce the purchase and installation costs of larger, more advanced systems.
- Auxiliary power: Some systems allow you to set up a smaller standby power storage unit to help provide energy for essentials in case of an emergency or system failure.
How do home batteries work?
Home batteries store energy generated by your solar panels or from the grid during off-peak hours, so that you can use it later when energy prices are higher or during power outages. They typically use Lithium-ion batteries, which are more efficient and durable than other battery technologies.
Do I need a home battery if I already have solar panels?
While solar panels can generate energy during the day, they don't produce electricity at night or during cloudy weather, making it necessary to use energy stored in batteries. Additionally, batteries allow you to be more independent from the grid, which can save you money and increase your home's energy security.
What type of home battery backup system do I need?
Backup battery systems are generally charged by utility grid electricity or solar power. If you live in an area where you get great levels of sunshine, then consider using solar power to charge your batteries up during the day.
Also: The 5 best solar chargers
Alternatively, if your power outages are infrequent, then consider topping up the batteries using electricity when the cost is low.
How much power do I need?
To ensure that your battery system can meet your power needs, you should first check the capacity of the batteries. This capacity is typically measured in kilowatt-hours (KWh). Additionally, you should measure the surge current requirements of the devices you want to power, especially if you plan to start a motor, such as a sump pump. Keep in mind that powering high-demand devices like pool filters or air conditioning units for extended periods may not be feasible with a battery system.
Cost is also an important factor to consider when designing a battery system. If your power requirements exceed 15KWh of inverter power or 30KWh per day for your batteries, the cost of the system may become prohibitive. It's also important to take into account potential inefficiencies, voltage drops, and other losses to ensure that your system can handle any situation that may arise. By considering all of these factors, you can design a battery system that meets your needs while staying within your budget.
How much load do you need from my battery backup system?
You will need to carefully consider peak load in KWh per day when calculating the size of battery power you need. If your energy requirements are low -- such as lighting -- then most backup systems will be able to cope with this. However, if you need to run items like sump pumps, air conditioning, or heavy start load items, then you will need to consider peak loads, too.