• Tesla Powerwall 3 for most homes that want the whole house backed up
• FranklinWH aPower 2 for keeping central AC and a water heater running in an outage
• Enphase IQ Battery 5P and 10C for homes that already have Enphase microinverters
• Generac PWRcell 2 for homes already on Generac equipment
• EcoFlow Delta Pro Ultra for starting small and scaling up to whole-home backup
• EcoFlow Delta Pro 3 with Smart Home Panel 2 for backing up the circuits you pick without a full installed battery system

EcoFlow prices on this page are the maker’s US store price in September 2026. These brands discount often, so the price moves. The four installed batteries are priced by installer quote.

What a home battery backup costs in 2026

The average home battery system on EnergySage’s marketplace cost $15,650 before incentives in the first half of 2026. Where you live changes how much a home battery costs, with a typical system averaging anywhere from $10,274 in Arkansas to $18,414 in Wyoming. Equipment makes up 50% to 60% of the total, so 40% to 50% of the bill goes to everything other than the hardware.

Quotes are easiest to compare by cost per kWh. Across the top 10 brands EnergySage tracks, that figure runs from $342 to $3,505 per kWh. In EnergySage’s 2026 ranking, the Powerwall 3 averages $998 per kWh and the FranklinWH aPower 2 averages $1,177. The two EcoFlow picks are sold as hardware, at $4,189 for the Delta Pro 3 kit and $4,199 for the Delta Pro Ultra base unit, EcoFlow’s US store prices in September 2026.

Homeowners who buy a battery in 2026 get no federal tax credit. The 30% Residential Clean Energy Credit, Section 25D, isn’t available for property placed in service after December 31, 2025. Leasing works differently. A company that owns a battery and leases it to you, or sells you its output, can still claim the business credit under Section 48E, because the new 48E deadlines for solar and wind don’t apply to storage and the law didn’t ban leased systems. The credit belongs to the company, so ask any lease provider whether it shows up in your price.

California’s Self-Generation Incentive Program pays per watt-hour of storage. As of September 2026, the general-market rate for home batteries steps down through funding tranches from $0.50 to $0.20 per Wh as money is claimed. The Equity budget pays $1.10 per Wh, and the Equity Resiliency budget pays $1.00 per Wh to customers in high fire-threat areas or those hit by Public Safety Power Shutoffs.

Massachusetts and Hawaii pay by the kilowatt instead. National Grid’s ConnectedSolutions program in Massachusetts pays $275 per kW of your battery’s average performance from June 1 to September 30, which comes to about $1,200 a year for a typical battery. The rate is locked for your first five summers. In Hawaii, the Battery Bonus program closed to new participants on July 1, 2024. Hawaiian Electric’s current program, Bring Your Own Device Plus, pays $400 per kW you commit, with no cap, and low- and moderate-income customers get another $400 per kW. BYOD Plus adds a monthly export credit, though NEM and NEM Plus customers don’t get it.

How much battery your home needs

The average US home used 10,791 kWh of electricity a year, or about 899 kWh a month. Divided by 365, that’s about 29.6 kWh a day, or roughly 1.23 kWh an hour. A single Powerwall 3 holds 13.5 kWh, a bit under half of an average day. Two FranklinWH aPower 2 units at 15 kWh each cover a full average day with a little to spare.

Counting major events, the average US customer had 1.4 interruptions totaling 5.6 hours in 2022, according to EIA. At 1.23 kWh an hour, 5.6 hours of average use comes to about 6.9 kWh, which one Powerwall 3 covers about twice over. EIA’s 2023 figure of about 2 hours across 1.3 interruptions leaves major events out, so it measures something different and can’t be set against the 2022 number.

A critical-loads setup backs up only the circuits you choose, which shrinks the power you need. A refrigerator runs at about 700 W and a half-horsepower furnace blower at about 800 W, per SizeMyHome’s appliance chart, so the pair needs 1,500 W, well inside the Delta Pro 3’s 4,000 W. A 2-ton central AC is the load that pushes you toward whole-home backup. It runs at about 3,800 W and needs about 5,800 W to start, so it nearly fills a 4,000 W plug-in system by itself, while the Powerwall 3’s 11.5 kW continuous rating covers even its starting draw.

Whole-home batteries versus plug-in battery backup

The difference is how much of your house runs at once. A whole home battery backup carries the full house at the same time, up to its power rating, which is 11.5 kW continuous for the Powerwall 3 and 10 kW for the aPower 2. Generac rates the PWRcell 2 for whole-home backup up to 200 amps, and Enphase batteries need an IQ Meter Collar to back up a full home.

A plug-in setup pairs a portable battery with a smart subpanel. EcoFlow’s Smart Home Panel 2 takes over 12 circuits and switches them to battery in 20 milliseconds, and the battery’s output caps how many of those circuits can run together. The panel still gets wired to your home’s main electrical panel, and EcoFlow’s store offers to connect you with a local electrician for that job. The Delta Pro Ultra gives you a path to whole-home backup without buying a full installed system on day one.

Home battery backup without solar works with either type. Every pick on this list charges from the grid, so panels are optional. If you have solar or plan to add it, the Powerwall 3 is the one with a built-in solar inverter, which lets a new array feed it DC power directly, and it can also run AC-coupled beside an existing inverter. The other installed picks connect on the AC side. The basics of how these batteries store and release power are in the battery energy storage explainer.

If all you want is a fridge and a phone charger through a short outage, a portable power station on its own may cover it.

The best home battery backup systems

The best battery backup for home use depends on how much of the house you want running in an outage and how much installation you’re willing to pay for.

Source: maker spec pages and datasheets from Tesla, FranklinWH, Enphase (5P, 10C), Generac and EcoFlow (Delta Pro Ultra, Delta Pro 3 kit). Every Powerwall 3 figure except the warranty, plus the aPower 2’s per-kWh price, is from EnergySage. EcoFlow prices are the maker’s US store price in September 2026.

If you’re shopping for Powerwall alternatives, the FranklinWH aPower 2 holds more per unit, 15 kWh against Tesla’s 13.5, and Enphase matches FranklinWH’s 15-year warranty term in smaller modules.

Tesla Powerwall 3

Our pick for most homes that want the whole house backed up.

The Tesla Powerwall 3 earns the top slot on price and power. EnergySage’s marketplace data puts its typical installed cost at $13,473, or $998 per kWh, about 13% below the average battery sold there, and it runs 11.5 kW continuously from 13.5 kWh of storage. It charges from the grid if you don’t have solar, and its built-in solar inverter can take DC power straight from a new array.

The Powerwall 3 isn’t part of the CPSC recall announced November 13, 2025, which covers about 10,500 older Powerwall 2 units sold from November 2020 to December 2022 over a fire hazard.

The drawback is that Tesla publishes no US list price, so you won’t know your cost until you get quotes, and EnergySage’s state averages for a typical battery system range from $10,274 to $18,414.

• Usable capacity: 13.5 kWh
• Continuous power: 11.5 kW
• Warranty: 10 years
• Price: installer quote, $13,473 typical installed

FranklinWH aPower 2

Best if your central AC and water heater have to keep running when the grid is down.

FranklinWH built the aPower 2 to carry heavy loads like AC and water heaters through an outage, and EnergySage names it the battery with the highest peak power in its 2026 ranking. Each unit holds 15 kWh and runs 10 kW continuously, with bursts to 15 kW for 10 seconds and 25 kW for one second. You can link up to 15 units on one aGate for 225 kWh, the highest ceiling on this list, and the warranty runs 15 years or 60 MWh of throughput.

FranklinWH doesn’t publish a price, and EnergySage’s data puts the aPower 2 at $1,177 per kWh, about 18% more than the Powerwall 3’s $998.

• Usable capacity: 15 kWh
• Continuous power: 10 kW
• Max stack: 225 kWh
• Warranty: 15 years or 60 MWh
• Price: installer quote, about $1,177 per kWh in EnergySage’s data

Enphase IQ Battery 5P and 10C

For homes that already make power with Enphase microinverters.

Both Enphase batteries here carry their own microinverters and connect on the AC side. The IQ Battery 5P holds 5 kWh and delivers 3.84 kW continuously, which lets you build up capacity in 5 kWh steps. The IQ Battery 10C holds 10 kWh at 7.08 kW in one box. Both carry a 15-year or 6,000-cycle warranty with at least 60% of capacity left at the end, tied with FranklinWH for the longest term here. Full-home backup takes an added IQ Meter Collar.

Enphase publishes no limit on how many batteries you can stack and no prices, so the size and cost of a big system depend on how an installer designs it.

• Usable capacity: 5 kWh or 10 kWh
• Continuous power: 3.84 kW or 7.08 kW
• Warranty: 15 years or 6,000 cycles
• Price: installer quote

Generac PWRcell 2

A fit for homes that already run a Generac standby generator or PWRmanager.

Rated for whole-home backup up to 200 amps, the Generac PWRcell 2 comes from the same lineup as Generac’s standby generators and PWRmanager. Each cabinet holds 9 kWh in the base M3 setup, and two cabinets reach 36 kWh. Continuous output runs from 5.2 kW on the M3 up to 11.5 kW. Generac rates a PWRcell 2 combined with AC-coupled solar at up to 26.5 kW of backup power.

The PWRcell 2 tops out at 36 kWh, the lowest published limit among the installed batteries here and far under FranklinWH’s 225 kWh, which makes it a poor fit for multi-day backup in a large home.

• Usable capacity: 9 to 36 kWh
• Continuous power: 5.2 to 11.5 kW
• Warranty: 10 years or 7.56 MWh
• Price: installer quote

EcoFlow Delta Pro Ultra

Suited to buyers who want to start with one unit and build toward whole-home backup later.

Of the whole-home-capable batteries here, only the EcoFlow Delta Pro Ultra has a price on the maker’s own store. The base unit costs $4,199 on EcoFlow’s US store in September 2026, and it holds 6.144 kWh. Adding battery packs takes it to 90 kWh with 15 of them. One inverter puts out 7.2 kW continuous and 10.8 kW peak, and more inverters stretch the range to 21.6 kW.

It charges from the grid or a generator and pairs with EcoFlow’s Smart Home Panel 2. EcoFlow calls it the only portable power station certified to both UL1973 and UL9540.

Its 5-year warranty is the shortest among the whole-home-capable picks, against 10 years for the Powerwall 3 and 15 for the aPower 2.

• Usable capacity: 6.144 kWh, up to 90 kWh
• Continuous power: 7.2 kW per inverter
• Warranty: 5 years
• Price: $4,199, EcoFlow’s US store price in September 2026

EcoFlow Delta Pro 3 with Smart Home Panel 2

The pick for backing up the circuits you care about most, with no whole-home install.

This EcoFlow Delta Pro 3 with Smart Home Panel 2 kit pairs a portable battery with a subpanel that takes over 12 circuits you pick and switches them to battery in 20 milliseconds when the grid drops. The battery holds 4.096 kWh to start and grows to 36 kWh with three units and six extra batteries. It charges from the wall without solar. The kit costs $4,189, plus an electrician to wire the panel to your main panel, which EcoFlow’s store can arrange.

At 4,000 W continuous, it can’t run a central AC alongside much else, since a 2-ton unit alone runs at about 3,800 W.

• Usable capacity: 4.096 kWh, up to 36 kWh
• Continuous power: 4,000 W
• Price: $4,189 for the kit

Battery backup versus a generator

A generator costs less to install. Angi puts typical installed costs at $1,512 to $8,803, with a national average around $5,157, and its whole-house tier of 22 to 48 kW at $5,000 to $18,000. EnergySage’s battery average is $15,650. The two figures come from different sources, so the comparison is rough, but the average battery system costs about three times the average generator install.

The generator keeps costing money after that. Angi estimates a 15 to 20 kW unit costs $90 to $220 a day to run, with annual fuel at $2,000 to $21,000 for natural gas or propane and $3,000 to $20,000 for diesel. A battery burns no fuel and refills from the grid or your solar once power is back.

A generator wins on runtime, since it keeps going for as long as it has fuel. A 13.5 kWh Powerwall 3 lasts about 11 hours at the average home’s 1.23 kWh an hour, longer if you cut back to critical loads or stack more batteries.

What would change the answer

At 30%, the federal credit that ended with 2025 would be worth about $4,700 on the $15,650 average system. That’s money a 2026 buyer now pays out of pocket. If you lease, the company that owns the battery can still claim Section 48E, and it’s up to the lease terms whether any of that reaches you.

State and utility programs can close part of the gap. In Massachusetts, the typical $1,200 a year from ConnectedSolutions adds up to about $6,000 over the five summers with a locked rate. In Hawaii, committing 5 kW from a 15 kWh battery to BYOD Plus earns $2,000 at $400 per kW, and Hawaiian Electric’s own example puts that setup’s export credit at about $52 a month.

Base Power is a Texas-only option that installs and keeps ownership of a 39.2 kWh battery at your home for a $695 install fee plus $19 a month, and you buy your electricity from Base at its own rate. It makes its money sending that battery’s power to the grid during peak demand.

• EcoFlow DELTA 3 Plus for most people
• EcoFlow RIVER 3 Plus for small budgets and short outages
• EcoFlow DELTA Pro 3 for home backup
• Jackery Explorer 1000 v2 for camping
• Anker SOLIX F3800 Plus for the most output and the most room to add batteries
• Anker SOLIX C1000 Gen 2 for the fastest recharge
• DJI Power 1000 for creators who already use DJI gear

What makes a good portable power station

Every pick here is a lithium battery with its own inverter and outlets, the carry-it-yourself end of battery energy storage. Continuous output is the first number to check. It’s the wattage an inverter can hold indefinitely, and it has to cover everything you plug in at once. Surge is a burst, often a few seconds long, that gets a compressor or motor started, and Samlex’s inverter guide calls buying to the surge number a common sizing mistake. Capacity, in watt-hours, sets how long that output lasts.

All seven picks use lithium iron phosphate cells, written LiFePO4 or LFP. A peer-reviewed comparison on ScienceDirect puts that chemistry beyond 2,000 charge cycles, against 1,000 to 2,000 for nickel manganese cobalt (NMC) cells, which also lose capacity faster. EcoFlow rates the DELTA 3 Plus for 4,000 cycles before it falls below 80% capacity.

If you’ll recharge during a long outage or at a campsite, compare charge times and solar input. The 1 kWh units here claim full wall charges in 49 minutes to 1.58 hours, and solar input ranges from 220W to 3,200W. Weights go from 10.4 lb to more than 130 lb. Only some take add-on batteries. The DELTA 3 Plus grows to 5 kWh, while the Jackery stays at 1,070 Wh.

Check recall notices for your exact model, too. EcoFlow recalled the Delta Max 2000 in October 2025 over burn and fire risk. That notice covers model EFD310 and none of the EcoFlow units on this page.

The best portable power stations compared

Source: specs from each maker’s product page, except the DELTA Pro 3’s weight, which OutdoorGearLab measured. Prices are each maker’s US store price in September 2026, and these brands discount often.

EcoFlow DELTA 3 Plus

For most households that want one unit for outages and weekends away.

The EcoFlow DELTA 3 Plus is our pick for most people, and it’s TechRadar’s best overall pick too. It stores 1,024 Wh in LiFePO4 cells and puts out 1,800W continuously, or 2,200W in EcoFlow’s X-Boost mode. A 1,500W wall charge fills it in 56 minutes, and its two solar inputs take up to 1,000W combined. When the grid drops, it switches to battery in under 10 milliseconds. You can grow it to 5 kWh with extra batteries later, and it carries a five-year warranty.

The catch is output. Its 1,800W continuous rating is half its 3,600W surge figure, and a 1,500W space heater running next to an 800W microwave needs 2,300W, more than even X-Boost’s 2,200W. On its own, that heater would drain the battery in about 41 minutes before conversion losses.

• Capacity: 1,024 Wh
• Output: 1,800W continuous, 3,600W surge
• Solar input: 1,000W
• Weight: 27.6 lb
• Price: $669

EcoFlow RIVER 3 Plus

A cheap backup you can carry anywhere, sized for a CPAP or a Wi-Fi router.

At $299 and 10.4 lb, the EcoFlow RIVER 3 Plus is the cheapest and lightest pick here. It holds 286 Wh in LiFePO4 cells rated for 3,000 cycles to 80% capacity, which EcoFlow puts at about 10 years of typical use. A wall charge takes about an hour, and like the DELTA 3 Plus, it switches to battery in under 10 milliseconds when the power cuts out.

Small, steady loads are what it’s built for. A ResMed AirSense 11 CPAP draws 56.1W in typical use, so 286 Wh runs it for about five hours before conversion losses. A Wi-Fi router averages about 10W, which stretches the same charge past 28 hours on paper. If that turns out to be too little, an EcoFlow extra battery raises the total to 858 Wh.

Its 600W continuous rating rules out an average 800W microwave or a 1,500W space heater. With solar input capped at 220W, it’s a unit for small electronics and short outages.

• Capacity: 286 Wh
• Output: 600W continuous, 1,200W surge with X-Boost
• Solar input: 220W
• Weight: 10.4 lb
• Price: $299

EcoFlow DELTA Pro 3

If you want the best portable power station for home backup and can leave it in one spot, start here.

OutdoorGearLab ran the EcoFlow DELTA Pro 3 through a runtime test, and its 4,096 Wh battery delivered 3,790 Wh, about 93% of the rating. OutdoorGearLab made it the top pick for home backup and ranked it second of the 14 units it tested, with a score of 81 out of 100. Its reviewers write that it powered almost every home essential during outages, including their fridge, lights, an electric kettle and a space heater.

Continuous output is 4,000W, and OutdoorGearLab measured an 8,000W surge. It takes up to 2,600W of solar, and in OutdoorGearLab’s charging test it refilled in 3.2 hours at 1,293 Wh per hour. One unit grows to 12 kWh with extra batteries, and three linked units reach 36 kWh. EcoFlow also sells it bundled with a 400W solar panel, and with 2,600W of solar input it’s our pick if you want the best solar generator for home backup.

It weighs 114.1 lb, and the wheeled cart is a separate accessory. OutdoorGearLab scored its portability 4.0 out of 10.

• Capacity: 4,096 Wh rated, 3,790 Wh in OutdoorGearLab’s test
• Output: 4,000W continuous, 8,000W surge
• Solar input: 2,600W
• Weight: 114.1 lb
• Price: $2,799

Jackery Explorer 1000 v2

For campers who want the lightest 1 kWh unit on this list.

If you’re carrying power to a campsite, the Jackery Explorer 1000 v2 gives you 1,070 Wh at 23.8 lb, and it’s TechRadar’s pick as the best portable power station for camping. It puts out 1,500W continuously with a 3,000W surge, and a wall charge takes 1.58 hours. Its two 8mm DC ports take up to 400W of solar, and Jackery puts a recharge from one 200W panel at about 7.5 hours. Jackery rates the LiFePO4 cells for 4,000 cycles to 70% capacity, a lower bar than the 80% EcoFlow and Anker quote for their 1 kWh units.

In the usual Jackery vs EcoFlow matchup at this size, the Explorer is 3.8 lb lighter than the 27.6 lb DELTA 3 Plus and $110 cheaper than its $669 store price. The DELTA answers with 1,800W of continuous output to the Explorer’s 1,500W, and 1,000W of solar input to its 400W.

The Explorer can’t take an add-on battery, so 1,070 Wh is the ceiling unless you buy a second unit and pair the two.

• Capacity: 1,070 Wh
• Output: 1,500W continuous, 3,000W surge
• Solar input: 400W
• Weight: 23.8 lb
• Price: $559

Anker SOLIX F3800 Plus

The one to buy if you want the most output and plan to keep adding capacity.

Anker’s SOLIX F3800 Plus puts out 6,000W continuously, 2,000W more than the DELTA Pro 3. It stores 3,840 Wh on its own, and each expansion battery adds 3.84 kWh. TechRadar named the SOLIX F3800 its pick for RVs and home backup, citing a 26.9 kWh expansion ceiling, and Anker’s page for the Plus now lists up to 53.8 kWh.

Solar input reaches 3,200W across two inputs, and Anker says a solar recharge can take under two hours in strong sun. A wall outlet charges it at up to 1,800W. It switches to battery in 20 milliseconds on a 120V outlet and carries a five-year warranty.

Listed weights run from 132.3 to 136.7 lb, which makes it a stationary battery with a handle. Its $2,599.99 store price is lower than the DELTA Pro 3’s $2,799 even though it puts out more continuous power.

• Capacity: 3,840 Wh, expandable
• Output: 6,000W continuous
• Solar input: 3,200W
• Weight: 132.3 to 136.7 lb
• Price: $2,599.99

Anker SOLIX C1000 Gen 2

Pick this one if a fast recharge matters more to you than room to grow.

The reason to buy the Anker SOLIX C1000 Gen 2 is how fast it refills. Anker rates it at 49 minutes from empty to full on a 1,600W wall charge, the fastest full-charge claim on this list, and OutdoorGearLab timed it at 56 minutes. OutdoorGearLab named it the best value in its test, and GearJunkie rated it 9.4 out of 10 as its best overall pick under the name Solix C1000 V2.

It’s rated at 1,024 Wh, and OutdoorGearLab measured 890 Wh of usable output, about 87%. Output is 2,000W continuous with a 3,000W surge. It takes up to 600W of solar and switches to battery in 10 milliseconds. Anker’s 10-year warranty is twice the five years EcoFlow gives the DELTA 3 Plus.

It can’t take an expansion battery, so 1,024 Wh is all it will ever hold. Its $529.99 store price is $139 less than the DELTA 3 Plus, which can grow to 5 kWh.

• Capacity: 1,024 Wh, 890 Wh in OutdoorGearLab’s test
• Output: 2,000W continuous, 3,000W surge
• Solar input: 600W
• Weight: 24.9 lb
• Price: $529.99

DJI Power 1000

Made for creators already using DJI gear.

The other 1 kWh units here put out 1,500W to 2,000W continuously. The DJI Power 1000 manages 2,200W, with a 4,400W peak, from 1,024 Wh of LFP cells that DJI says keep at least 70% of their capacity after 4,000 cycles. It charges to 80% in about 50 minutes and to full in 70, and it takes up to 800W of solar from as many as six panels. Registering it extends the warranty to five years.

TechRadar’s pick for creators and drone users is the related Power 1000 Mini. The Power 1000 here is DJI’s current mainline US model.

Its SDC accessory ports use DJI’s proprietary format, which ties you to DJI’s own accessories. DJI also doesn’t state a switchover time for backup use, so for home backup an EcoFlow or Anker unit with a listed switchover time is the safer choice. At $699, it’s the most expensive 1 kWh unit on this list.

• Capacity: 1,024 Wh
• Output: 2,200W continuous, 4,400W peak
• Solar input: 800W
• Weight: about 28.7 lb
• Price: $699

How to size a portable power station

Watts are how fast an appliance draws power. Watt-hours are how much energy a battery holds, so dividing a battery’s watt-hours by the average watts of what you plug in gives you hours of runtime. The continuous output rating has to clear the highest draw you’ll hit at any one moment.

Say you want these running through an outage.

• A refrigerator with a 500W nameplate, which averages about 167W because it cycles on and off, per EnergySage
• A ResMed AirSense 11 CPAP, at 56.1W typical and 73.2W peak
• A Wi-Fi router, at about 10W

The averages add up to about 233W. The RIVER 3 Plus’s 286 Wh covers about 1.2 hours of that, and the DELTA 3 Plus’s 1,024 Wh about 4.4 hours. On its rated 4,096 Wh, the DELTA Pro 3 would last about 17.6 hours.

You won’t get every rated watt-hour out of the outlets. OutdoorGearLab measured 3,790 Wh from the DELTA Pro 3, about 93% of its rating, and 890 Wh from the C1000 Gen 2, about 87%. Two tests from one reviewer don’t make a rule, but at the DELTA Pro 3’s measured figure the same load runs about 16.3 hours.

For output, add the fridge’s 500W nameplate to the other two peaks, which gives about 583W. That fits under even the RIVER 3 Plus’s 600W continuous rating, and the fridge compressor’s startup kick is what the surge rating is for, per Samlex. Plug in an 800W microwave too and the peak jumps to about 1,383W, past the RIVER 3 Plus but inside the Jackery’s 1,500W. Add a 900W window AC on top and you need about 2,283W, which only the DELTA Pro 3 and F3800 Plus can supply.

When a home battery makes more sense

At EnergySage’s 167W average, a fridge alone uses about 4,000 Wh a day. That’s close to the DELTA Pro 3’s entire 4,096 Wh rating and more than the 3,790 Wh OutdoorGearLab measured from it. Add the Wi-Fi router from the example above and a full day comes to about 4,250 Wh, more than any single unit here holds without expansion batteries, and that’s before adding a CPAP overnight.

The two units that can grow past that, the DELTA Pro 3 and the F3800 Plus, already weigh 114.1 lb and more than 130 lb before you add a battery. If you’re planning for outages that last days, or for loads like a 1,500W space heater, a home battery installed at the house is worth pricing against a stack of expansion packs. Our home battery backup guide compares those systems and what they cost to install.