Whole-home battery backup: Pros, cons, and the best batteries

Installing a whole-home battery backup system means you won’t need to break out the candles or worry about keeping the refrigerator closed during power outages. With independence from the utility grid, you can avoid the inconvenience of outages without sacrificing your daily routines.

Most home energy storage systems provide partial backup power during outages. These smaller systems support critical loads, like the refrigerator, internet, and some lights. Whole-home setups allow you to maintain normal energy consumption levels—but at a cost. You’ll need about three times as much power for a whole home backup system, which is about three times the price of a partial home setup. 

Partial home battery backup systems generally make more sense for the average American home, but a whole-home setup may be worth it if you live in an area with frequent blackouts. Let’s explore the best batteries for whole-home backup, how to compare your options, and how much storage capacity you’ll need.

*Prices reflect the federal tax credit but don't include solar panels, which you'll need to keep your battery charged during an outage.

The difference between whole-home and partial-home battery backup systems is pretty self-explanatory: Whole-home battery backup systems can power your entire home in the event of an outage, whereas partial-home setups support the essentials. The actual batteries are the same; whole-home backup systems just have more of them. 

To power your entire home during an outage, you’ll need a battery system that is about the size of your daily electricity load (about 30 kilowatt-hours (kWh) on average). Comparatively, partial-home battery backup systems usually store around 10 to 15 kWh. 

Given that power outages are infrequent in most parts of the country, a partial-home battery backup system is generally all you’ll need. But, if your utility isn’t always reliable for power, whole-home battery backup may be the way to go.

Solar plus storage systems enhance your home’s resiliency

Whether partial or whole-home, battery backup systems insulate you from disruptions caused by power outages, effectively boosting your home’s resiliency.

Pairing your solar panels with a battery backup system provides you with renewable resilience. If your solar system is grid-connected (most are), your panels will shut down with the grid for safety reasons; even if your solar panels generate enough electricity to meet 100% of your home’s needs, you’ll still be without power during an outage. A battery backup system can keep your home running on renewable energy even during a blackout.

Duracell Power Center Max Hybrid: Best overall

The Duracell Power Center Max Hybrid battery was our top pick for the best solar battery of 2024, and it’s also our top pick for the best whole-home battery backup—it’s that good. 

Not only does it provide ample storage capacity, but it also has the highest continuous power (crucial for a whole-home setup). It’s a top performer in just about everything, which is why we’re so impressed with its price—the Duracell Power Center Max Hybrid is pretty affordable compared to some other batteries on our list. 

This battery is AC-coupled, so it loses some energy during inversions. Still, it’s highly efficient at 96%. 

HomeGrid Stack’d Series: Most powerful and scalable

The HomeGrid Stack’d series is the only product on our list capable of meeting whole-home battery backup needs with a single battery stack. 

The Stack'd Series is seriously powerful, with an impressive usable capacity of 38.4 kW and continuous power up to 14.4 kW. Its modular design allows you to scale as needed so your battery backup system can grow with your needs. It’s also our most efficient battery. 

The biggest downside is that HomeGrid’s warranty guarantees 10% less initial capacity at the end of its term than the rest of the batteries on our list.   

Tesla Powerwall 3: Flexible coupling 

The Powerwall 3 is a solid battery all around: It provides good storage capacity and continuous power ratings, can be AC or DC-coupled, and includes a Storm Watch feature that readies your battery for an outage. We should also mention that Tesla (and FranklinWH) are to thank for the decrease in storage prices this past year. 

When AC-coupled, the Powerwall isn’t as efficient as other batteries on our list. 

FranklinWH aPower: Longest warranty

FranklinWH is the fastest-growing battery brand on EnergySage. The company gained a 10% marketplace share in just a year, securing its place as the third most quoted battery. Along with Tesla, FranklinWH helped drive down storage prices. 

The aPower battery provides a pretty good bang for your buck. It adequately stores 13.6 kWh, but its continuous power is the lowest on our list. Its biggest differentiator is its warranty—FrankinWH offers two more years of coverage than the rest of our top batteries. 

This battery can only be AC-coupled, so it’s no surprise that it ranks lowest for efficiency. 

Generac PWRcell: Runner up for scalability

Generac has decades of experience in backup power and added the PWRcell to its offerings in 2019. 

The PWRcell is second best for capacity and efficiency. Like HomeGrid’s Stack’d Series, the PWRcell’s modular design allows you to customize capacity to fit and scale with your unique needs. 

The PWRcell’s NMC battery chemistry is less stable than the rest. Additionally, its continuous power isn’t impressive compared to our other options, and it’s also the most expensive on our list. 

The best whole home backup batteries

*Price per kWh reflects the average battery cost from that brand, not the individual model.

**Total system price reflects the federal tax credit but doesn't include solar panels.