10 Best Whole Home Battery Backups (June 2026)

Power outages are becoming more common across the country, and relying on candles and flashlights is not a real solution. After spending months researching and comparing home energy storage systems, our team put together this guide to help you find the best whole home battery backups available right now. We looked at capacity, power output, expandability, charging speed, and real-world reliability from actual users who have lived through outages with these systems.

A good whole house battery backup system does more than just keep the lights on. It protects your food, keeps medical devices running, lets you work from home without interruption, and can even save you money on electricity bills through time-of-use optimization. Whether you have solar panels or just want grid backup, there is a system in this guide that fits your needs and budget.

We reviewed 10 of the most popular home battery backup systems on the market for 2026, ranging from compact portable units to full-scale whole home power stations. Each one was evaluated on real user feedback, technical specifications, warranty coverage, and overall value. Here is what we found.

Top 3 Picks for Whole Home Battery Backups

10 Best Whole Home Battery Backups in 2026

1. EcoFlow DELTA Pro Ultra – Best Overall Whole Home Backup

This is the system I would pick if I needed to power my entire house during an extended outage. The EcoFlow DELTA Pro Ultra delivers 7200W of continuous output with dual voltage support, meaning it can handle everything from your refrigerator to a central air conditioning unit without breaking a sweat. I have seen users report running a 3-ton AC system on this unit alone, which is something most portable systems simply cannot do.

The standout feature for me is the 0-ms online UPS transfer time. When the grid drops, this system switches over instantly with zero interruption. Your computers, TVs, and network equipment stay on as if nothing happened. That is a big deal if you work from home and cannot afford even a momentary power loss during an important video call or file upload.

Capacity starts at 6144Wh and scales all the way up to 90kWh with additional battery packs. For context, a typical home uses about 30kWh per day, so even the base configuration can keep essential loads running for a full day. The 2-hour full recharge time means you can top it off quickly between outages or charge it during off-peak hours to save on your electricity bill.

The smart home panel integration and app-based circuit prioritization are genuinely useful. You can decide which circuits in your home get power first during an outage, so your furnace and refrigerator take priority over less critical loads. This kind of control used to require expensive custom installations, but EcoFlow built it right into the app.

Best Use Cases for This System

This system is ideal for homeowners who want true whole-home backup without installing a permanent wall-mounted system. It works particularly well for homes between 1,500 and 3,000 square feet with moderate power needs. If you have a well pump, central AC, or an electric dryer, the 240V support makes this one of the few portable systems that can actually run those appliances. It is also a strong choice if you have solar panels, since it integrates cleanly with most residential solar setups.

People who work from home and need guaranteed uptime will appreciate the zero-transfer UPS. Medical device users who cannot tolerate any power interruption should also consider this system seriously. The expandability means you can start with the base unit and add batteries over time rather than paying for everything upfront.

What to Consider Before Buying

At 186 pounds, this is not something you will be moving around casually. Plan to set it in a semi-permanent location, ideally near your breaker panel or transfer switch. The total cost can climb quickly if you add multiple expansion batteries to reach higher capacities. Some users have reported that EcoFlow customer support response times are slower than expected for a product at this price point, so keep that in mind if after-purchase support is important to you.

2. Anker SOLIX C2000 Gen 2 – Best Value for Home Backup

The Anker SOLIX C2000 Gen 2 is the system I keep recommending to friends who want reliable home backup without spending thousands. At just 41.7 pounds, it is one of the lightest units in its class and small enough to store in a closet when not in use. But do not let the size fool you. The 2400W rated output with 4000W peak power can run a refrigerator, several lights, a TV, and charge all your devices simultaneously.

What really sets this unit apart is the 58-minute full charge time. Most competitors take 2 to 3 hours to recharge. When you are dealing with intermittent outages, getting back to full capacity in under an hour is a significant advantage. I have read reports from users in hurricane-prone areas who recharge between storm bands and stay powered throughout multi-day events.

The 2048Wh capacity will keep a standard dual-door refrigerator running for up to 32 hours on a single charge. Add the expansion battery and you get 4kWh total, which doubles that runtime. For most families dealing with typical 4 to 8 hour outages, the base configuration is more than enough. The LiFePO4 chemistry means the battery will last for years with minimal degradation.

Anker included six different charging methods, which is more than most systems at this level. You can charge from a wall outlet, solar panels, your car, and even a combination of sources. The app connectivity via Bluetooth and WiFi lets you monitor battery levels and power usage from anywhere in the house. The 4.8-star average rating across 338 reviews tells you that real users are genuinely happy with this product.

Ideal Users for the C2000 Gen 2

This unit is perfect for apartment dwellers, small to medium-sized homes, and anyone who wants a grab-and-go backup solution. If your main concern is keeping the refrigerator cold, the internet running, and phones charged during typical outages, this handles all of that comfortably. Campers and RV owners will also appreciate the portability and the car charging option for off-grid trips.

Budget-conscious buyers who still want quality should start here. You get Anker reliability and a 5-year warranty at a price point well below the larger systems. It is also a great entry point if you are new to home battery backups and want something that just works without a steep learning curve.

Limitations to Keep in Mind

The 2400W output will not run heavy appliances like central air conditioning, electric dryers, or large well pumps. If you need 240V or want to power your entire home simultaneously, you should look at the larger systems in this guide. Also, while the expansion battery doubles your capacity, the maximum of 4kWh is still modest compared to systems that scale to 20kWh or more. Solar panel accessories are sold separately and add to the total cost.

3. AFERIY 3840Wh Portable Power Station – Best Budget Option

The AFERIY 3840Wh delivers an impressive amount of power for the money. You get 3840Wh of LiFePO4 battery capacity with 3600W of continuous output and 7200W peak, which is enough to run most household essentials through a typical outage. For the price, I have not found another system that offers this much storage capacity with these power specs.

What surprised me about this unit is the feature set relative to its cost. The UPS function switches over in under 10 milliseconds, which is fast enough to keep computers and network equipment running without a restart. The 15 output ports cover every device type you might need, including a 100W USB-C PD 3.0 port for fast-charging laptops. And the 7-year warranty is one of the longest in this category, giving real peace of mind about long-term reliability.

Charging is flexible with four methods including AC, solar, car, and combined AC plus solar. Under optimal conditions you can get a full charge in as fast as 1.5 hours. The expandable design lets you add battery packs to reach 11.5kWh total, which is enough to power a small home for more than a day. Several users on forums mentioned choosing this system specifically because they could start small and expand later.

Real user feedback is generally positive. People praise the build quality and the value for money. Customer support gets good marks for responsiveness when issues come up. The most common complaints are about the app interface being a bit clunky and some units having minor display glitches. Neither of these affects the core backup performance, which is what matters most during an actual power outage.

Who Should Consider This Unit

If you want the most battery capacity per dollar and do not need dual-voltage 240V output, this is your best bet. It is well-suited for homeowners in areas with frequent but short outages who want to keep essentials running. The expandability also makes it a good starting point for someone who wants to build up their backup capacity over time rather than buying everything at once.

People with home offices will appreciate the fast UPS switchover and the USB-C PD port for keeping laptops charged. Anyone who values long warranty coverage should also take a close look at the 7-year support period, which is two years longer than most competitors.

Potential Drawbacks

At 104.7 pounds, this unit is not portable in any meaningful sense. You will want to pick a spot and leave it there. The app could use better design and more reliable connectivity, according to multiple user reviews. Also, this system does not support 240V output, so it cannot run heavy appliances like electric dryers, central AC, or large well pumps on its own.

4. EcoFlow DELTA Pro 3600Wh – The Popular Workhorse

The EcoFlow DELTA Pro has been one of the most popular home battery backup systems on the market, and for good reason. With 3600Wh of LFP battery capacity and 3600W of output, it hits a sweet spot between portability and power. The X-Boost feature pushes output up to 4500W, letting you run slightly larger appliances than the rated specs suggest.

I like the 15 output ports on this unit. You get 5 AC outlets, multiple USB-C and USB-A ports, DC outputs, a car port, and an Anderson port. During an outage, you can plug in your refrigerator, several lamps, your modem and router, charge phones and laptops, and still have ports left over. This eliminates the need for power strips and adapters during an already stressful situation.

The expandable battery system is where this unit really shines for whole-home applications. You can scale from 3600Wh up to 25kWh with additional battery packs. Pair two DELTA Pro units together and you get 7200W of combined output with double the capacity. This modular approach means you can start with one unit and grow your system as your needs or budget change.

Charging is fast and flexible with five different methods. The X-Stream charging gets you from zero to full in 2.7 hours from a standard wall outlet. Solar charging with four 400W panels takes about 2.8 hours. You can even charge at EV charging stations, which is a unique option that comes in handy during extended outages when your home has no power at all.

When This System Makes Sense

The DELTA Pro is a strong choice for medium to large homes where you want backup for essential circuits but maybe not the whole house at once. It works well for running refrigerators, lights, entertainment systems, and small appliances through multi-day outages. RV owners and campers also gravitate toward this unit because of the balance between capacity and the ability to actually move it around, even at 99 pounds.

If you already have solar panels or plan to add them, the DELTA Pro integrates smoothly. The app gives you real-time monitoring of power input and output, so you can see exactly how much solar energy you are capturing and how long your battery will last at current usage levels.

Things to Watch Out For

Some users have reported the unit shutting down with overload errors even when the connected load appears to be within specs. This usually happens during motor startup surges from appliances like refrigerators and pumps. EcoFlow customer support has been criticized for slow response times, which is frustrating when you need help during an active outage. The weight at 99 pounds means you really need two people to move it safely.

5. Anker SOLIX F3800 – Heavy-Duty Home Power

The Anker SOLIX F3800 is built for serious home backup. With 6000W of AC output and dual 120V/240V capability, this system can run heavy appliances that most portable units cannot handle. The NEMA 14-50 port lets you charge an electric vehicle directly, which is a feature almost no other portable power station includes.

I found the expandability particularly appealing. You start with 3840Wh and can add up to six expansion battery packs to reach 26.9kWh. That is enough to power an average home for close to a full day. Anker uses their InfiniPower technology with EV-class LFP cells, which are designed to last 10 years under normal use. Pair two units together and you get 12,000W of combined output, which rivals permanently installed systems.

The 240V support means you can run 240V appliances like electric dryers, well pumps, and certain power tools. For homeowners in rural areas who depend on well pumps, this capability alone might make the F3800 worth considering over smaller units. The Wi-Fi and Bluetooth app connectivity lets you monitor everything from your phone, including individual port power draw and estimated runtime.

Users report that the build quality is excellent and the system runs quietly compared to gas generators. The 5-year warranty is standard for this category, but the 10-year expected lifespan gives confidence in long-term reliability. Cold weather charging has been an issue for some users, so if you live in a very cold climate, plan to keep this unit in a temperature-controlled space.

Best Applications for the F3800

This system is ideal for larger homes with 240V appliance requirements. If you have an electric vehicle and want backup charging capability, the NEMA 14-50 port eliminates the need for a separate charging setup. Homes with well pumps, electric dryers, or workshop equipment that need 240V power will benefit from the dual voltage output.

It is also a strong option for anyone planning to build a modular system over time. Start with the base unit and add batteries as your budget allows. The ability to pair two F3800s together gives you a clear upgrade path to 12,000W output without replacing your original investment.

Considerations Before Purchasing

At 132 pounds, plan for a permanent or semi-permanent installation location. The total cost escalates quickly when you start adding expansion batteries to reach higher capacities. Some users have reported issues with solar charging in cold conditions, so factor in your local climate. Generator charging also has some limitations that are worth understanding before you commit to this system.

6. Jackery HomePower 3600 Plus – Portable Power with Wheels

Jackery nailed the design with the luggage-style wheels and telescopic handle on the HomePower 3600 Plus. At 77 pounds, it is still heavy, but the wheels make it genuinely possible for one person to move it from room to room or out to a vehicle. That is a small detail that matters a lot when the power is out and you need to reposition the unit.

The 3584Wh capacity with 3600W output covers most home backup needs. You can expand up to 21kWh with additional battery packs, and the dual voltage support in parallel mode means you can run 240V appliances when you connect two units together. The ceramic membrane battery cells are tested at 302 degrees Fahrenheit, which adds a layer of safety confidence.

Charging is flexible with four options including the hybrid AC plus DC method that gets you to full capacity in just 2 hours. Solar charging takes about 4 hours with appropriate panels. The 6000 cycle rating is one of the highest in this class, meaning the battery should maintain strong performance for a decade of regular use.

Forum users who own this system appreciate the build quality and the portability advantage of the wheeled design. Several people mentioned using it for both home backup and RV camping, which the dual-use design supports well. The main complaints center around runtime for high-draw appliances like air conditioners, where actual performance falls short of what some users expected based on the marketing.

Who This System Fits Best

The HomePower 3600 Plus is a great match for people who need to move their backup system around regularly. RV owners, campers, and homeowners who want to store the unit in a garage and wheel it inside during outages will appreciate the design. The 240V support in parallel mode makes it viable for larger homes if you invest in two units.

Anyone who values long-term battery health should note the 6000-cycle rating, which is significantly higher than most competitors rated at 3000 to 4000 cycles. This means the battery degrades more slowly over time, retaining more of its original capacity after years of use.

What Might Give You Pause

Extended air conditioner runtime is not this system’s strength. If you live in a hot climate and need AC backup for hours at a time, look at the EcoFlow DELTA Pro Ultra instead. Some users report actual battery life is shorter than the advertised numbers, particularly when running high-wattage appliances continuously. The weight, even with wheels, still makes lifting it into a vehicle a two-person job.

7. OUPES Guardian 6000 – 240V Power at a Fair Price

The OUPES Guardian 6000 caught my attention because it offers 240V dual voltage output at a price point where most competitors only give you 120V. That means you can run heavy appliances like electric dryers and well pumps without stepping up to a much more expensive system. The 4608Wh LiFePO4 battery provides solid runtime for essential loads.

One feature that sets this unit apart is the transfer switch ready design. OUPES designed it so you can connect it to your home’s electrical system without needing a licensed electrician. For homeowners who want a more permanent installation without the hassle and cost of professional wiring, this is a real advantage. The 90-minute rapid recharge is also one of the fastest in this category.

The 11 output ports include NEMA 14-50R, TT-30R, and L14-30E configurations, covering RV, generator, and home transfer switch connections. You can expand capacity from 4608Wh up to 41,472Wh with additional battery packs. The 6000W continuous output with 7200W boost and 9000W surge gives you plenty of headroom for motor startup loads from compressors and pumps.

Users on Reddit and other forums highlight this as one of the best values for getting 240V capability. The US-based customer support gets positive mentions, which is important for a product you might depend on during emergencies. The main complaints are about the app being unreliable for monitoring and the Bluetooth-only status display that requires your phone to check battery levels.

When to Choose the Guardian 6000

If you need 240V output but cannot justify the price of the EcoFlow DELTA Pro Ultra or Anker F3800, this is your best alternative. It works well for homes with well pumps, electric dryers, or other 240V appliances that need backup power. The transfer switch ready design makes it appealing for anyone wanting a cleaner installation without hiring an electrician.

RV owners with 50-amp service will also find the NEMA configurations useful. The 90-minute recharge means you can top off quickly between uses or during brief periods of grid power between outages.

Known Issues to Consider

The app connectivity is the most common complaint. Users report difficulty connecting and maintaining a stable Bluetooth connection for monitoring. If you prefer checking battery status on a built-in screen rather than your phone, this unit only has a Bluetooth indicator, not a full display. Solar charging efficiency drops off if you cannot position panels optimally, which can be frustrating for off-grid use.

8. GROWATT HELIOS 3600 – Cold Weather Champion

The GROWATT HELIOS 3600 stands out for one reason that matters a lot if you live somewhere cold: it has cold-start technology that works down to negative 22 degrees Fahrenheit. Most lithium battery systems struggle or refuse to charge in freezing temperatures. If you live in a northern climate where winter outages are common, this feature alone could be the deciding factor.

Beyond cold weather performance, the HELIOS 3600 is a well-rounded system with 3600W of output and 3600Wh of LFP battery capacity. The 16 plug-and-play ports give you plenty of connection options. Expansion is straightforward with up to 18kWh using four additional batteries or 36kWh in a split-phase parallel configuration for whole-home coverage.

The app includes a time-of-use optimization feature that lets you schedule charging during off-peak hours and discharge during peak pricing. For homeowners on time-of-use electricity rates, this can translate into real savings on monthly bills, not just outage protection. The 2000W solar charging capability gets you to full capacity in about 2.8 hours with enough panel wattage.

The 15ms EPS switchover is fast enough to keep computers and network equipment running without interruption. Users in extreme weather areas praise the cold-start feature, with several reporting successful operation during winter storms when temperatures dropped well below zero. The EV-grade LFP cells are rated for over 4000 cycles, which should translate to more than a decade of regular use.

Ideal Scenarios for This System

If you live in a cold climate where temperatures regularly drop below freezing, this is the system I would recommend first. Winter power outages combined with cold temperatures are exactly when you need backup power most, and this unit will not leave you stranded. It is also a good pick for anyone on time-of-use electricity rates who wants to save money on daily energy costs, not just use it for emergencies.

The 36kWh expandability makes it suitable for larger homes if you invest in additional batteries. The split-phase parallel connection for 240V output gives you whole-home backup capability that scales with your needs.

Potential Downsides

Some users report a slight humming noise during charging, which might be noticeable in quiet environments. The handle and wheel positioning has been criticized as awkward, making it less convenient to move than the Jackery with its luggage handle. At 51 pounds it is lighter than many competitors but still requires some effort to reposition.

9. Jackery HomePower 3000 – Complete Solar Kit Included

The Jackery HomePower 3000 is the only system in this guide that comes with solar panels included in the box. You get two 200W panels along with the 3072Wh power station, which means you have a complete off-grid power solution from day one without buying anything extra. For people who want a grab-and-go solar backup kit, this is hard to beat.

The 3600W output with 7200W surge handles most household appliances comfortably. The UPS functionality switches over in under 20 milliseconds, which is fast enough to keep computers and sensitive electronics running without interruption. Jackery uses CTB (Cell-to-Body) technology, which is a first for portable 3kWh-class power stations, and it allows the unit to be 47 percent smaller and 43 percent lighter than comparable models.

At 59.52 pounds, this is one of the more manageable units in its capacity class. One person can move it with reasonable effort, which is not something you can say about most 3kWh systems. The TT-30 RV port is a nice touch for RV owners, providing plug-and-play power without adapters.

The included solar panels are functional and easy to set up. You can position them outside during the day to keep the battery topped off during extended outages. Users report good results running refrigerators for 1 to 2 days on a single charge, and the ChargeShield 2.0 AI technology helps optimize charging speed and battery lifespan over time.

Who Should Buy This Kit

If you want a complete solar backup solution without researching and buying separate components, this is the most convenient option. It is ideal for homeowners who experience occasional outages and want something they can set up quickly when needed. RV owners will appreciate the included solar panels and TT-30 port for off-grid camping trips.

First-time battery backup buyers who want everything in one package should consider this kit. The included panels, built-in UPS, and straightforward operation make it accessible even if you have never used a power station before. The 5-year warranty provides good coverage for the investment.

Limitations to Know About

Unlike most other systems in this guide, the HomePower 3000 cannot be expanded with additional battery packs. What you buy is what you get. Some users have reported random shut-offs that require a manual restart, which is concerning for unattended backup applications. The Alexa smart home integration that was advertised does not actually work according to multiple reviews.

10. EcoFlow DELTA Pro Ultra 12kWh – Pre-Built Whole Home Kit

The EcoFlow DELTA Pro Ultra 12kWh is the pre-configured version of our top pick, bundled with two batteries and the inverter as a complete kit. If you know you need serious whole-home capacity and do not want to piece a system together module by module, this kit gives you 12kWh of storage and 7200W of output right out of the box.

With 12kWh of storage, you have enough capacity to power an average home through most of a day. The 7200W output with dual voltage handles heavy appliances including central air conditioning, electric dryers, and well pumps. The smart home panel integration lets you manage which circuits get priority during an outage, and the modular design means you can keep adding batteries up to a massive 90kWh total.

This kit is designed for permanent or semi-permanent home installation. The modular inverter plus battery system is clean and professional-looking, suitable for a garage or utility room installation. Multiple users have set this up as their primary backup system and report successful whole-home operation during multi-day outages.

The trade-off for this level of capacity and power is the physical footprint and weight. At 293.6 pounds total, this system is not going anywhere once you set it up. Plan for a dedicated installation location with adequate ventilation and access to your electrical panel. The smart home panel accessory is recommended for the cleanest installation.

When This Kit Is Worth It

If you are building a whole-home backup system and want everything in one purchase rather than accumulating components over months, this kit saves you time and ensures compatibility between all parts. Homes larger than 2,500 square feet with multiple high-draw appliances will benefit from the 12kWh capacity and 7200W output. It is also the right choice if you plan to eventually expand to 30kWh or more and want a system designed from the ground up to scale.

People who have already invested in solar panels and want a storage solution that integrates cleanly should also consider this kit. The EcoFlow ecosystem is well-supported and the smart home integration adds genuine value for managing your home energy usage.

Important Caveats

The power loss during charge and discharge cycles has been reported at 15 to 32 percent by some users, which is higher than ideal. This means you may not get the full 12kWh of usable capacity in practice. The battery level indicator is not always accurate, making it hard to know exactly how much power you have left. Setup is complex enough that most users will benefit from hiring a qualified contractor, which adds to the total cost.

How to Choose the Right Whole Home Battery Backup

Picking the right home battery backup system comes down to understanding your power needs, your budget, and how you plan to use it. After comparing all 10 systems in this guide, here are the factors that matter most when making your decision.

How to Size Your Whole Home Battery Backup

The first step is calculating how much power you actually need. Start by listing the essential appliances you want to keep running during an outage. A typical refrigerator uses about 150 to 200 watts continuously, a furnace blower uses around 500 to 800 watts, and a well pump can draw 1000 to 2000 watts when running. Add up the running wattage of everything you need, then add 20 percent for surge headroom.

For capacity, estimate how many hours or days you want backup power. A 3000Wh battery can run a refrigerator for about 15 to 20 hours. A 6000Wh battery doubles that. If you want to power more appliances for longer periods, look for expandable systems that let you add capacity over time. Most homes need between 5kWh and 15kWh for meaningful whole-home backup.

Key Features That Actually Matter

Output wattage determines what you can run simultaneously. A 2400W system handles essentials like refrigerators, lights, and electronics. A 3600W system adds small appliances and window AC units. A 6000W plus system with 240V support covers heavy appliances like central AC, dryers, and well pumps.

UPS transfer time matters if you work from home or have sensitive electronics. Look for systems with transfer times under 20 milliseconds. The EcoFlow DELTA Pro Ultra leads with 0-ms online UPS, while most good systems are under 15ms.

Battery chemistry is a durability consideration. LiFePO4 (LFP) batteries are the current standard, offering 3000 to 6000 charge cycles before significant degradation. All 10 systems in this guide use LFP chemistry, which is a good baseline for long-term reliability.

Solar Panel Integration Considerations

You do not need solar panels to use a home battery backup. All of these systems charge from standard wall outlets. However, solar panels extend your runtime during extended outages when grid power is unavailable for days. If you want solar charging, look at the maximum solar input wattage each system supports. Higher solar input means faster recharging from panels.

For grid-tied homes with existing solar installations, make sure the battery system you choose is compatible with your inverter. AC-coupled systems work with most existing solar setups, while DC-coupled systems are more efficient but may require compatible equipment. The EcoFlow and Anker systems tend to have the broadest compatibility with residential solar installations.

Installation and Maintenance

Portable power stations like the ones in this guide do not require permanent installation. You plug them in to charge and connect appliances directly to the unit. For whole-home integration, you will need a transfer switch connected to your electrical panel. Some systems, like the OUPES Guardian 6000, are designed for easier transfer switch setup.

Maintenance is minimal with LFP battery systems. Keep them charged between 30 and 80 percent for longest life if you are storing them. Run a full charge and discharge cycle every 3 to 6 months. Store in a temperature-controlled environment when possible, though the GROWATT HELIOS 3600 is specifically designed for cold weather operation. Check the manufacturer app for firmware updates periodically, as these can improve performance and add features.

Frequently Asked Questions About Whole Home Battery Backups

Final Thoughts on Whole Home Battery Backups

Finding the best whole home battery backups for 2026 comes down to matching your power needs with the right system. The EcoFlow DELTA Pro Ultra is the top overall choice for homeowners who want serious whole-home power with 7200W output and massive expandability. The Anker SOLIX C2000 Gen 2 is the best value pick for most households, offering fast charging and reliable performance at an accessible price. And the AFERIY 3840Wh delivers the most capacity per dollar for budget-conscious buyers.

All 10 systems in this guide use safe, long-lasting LiFePO4 battery chemistry with warranties of 5 years or more. Whether you deal with occasional outages or want daily energy savings through time-of-use optimization, there is a system here that fits your home and budget. Pick the one that matches your power requirements, and you will have reliable backup power the next time the grid goes down.