FranklinWH battery: The complete review

Energy storage is becoming an increasingly popular addition to residential solar installations, and more and more companies have started offering storage solutions. In 2022, FranklinWH debuted their first storage product: the aPower. Unlike many other storage options on the market, the aPower must be installed with FranklinWH's load management system, the aGate. As FranklinWH states, this Home Power Solution (the aPower + aGate) "interfaces between the grid, the loads, the generator, and the solar system," allowing you to more easily monitor and control the loads that your storage system is powering.

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The FranklinWH aPower pairs well with solar panel systems, especially if your utility has reduced or removed net metering, introduced time-of-use rates, or instituted demand charges for residential electricity consumers. Installing a storage solution like the aPower with a solar energy system allows you to maintain a sustained power supply both day and night, as long as you store enough power from your solar panels when the sun is shining.

As with many other home battery products, the aPower is sized for day-to-day use at your home and primarily designed for pairing with a solar panel system. When your solar panels produce more electricity than you can use in your home, you can store the excess electricity in the battery system instead of sending it back into the grid. Later, when your panels aren't producing enough electricity to meet your home's needs, you can use the stored energy in your battery instead of buying it from your utility company.

FranklinWH designed their Home Power System to "bring energy security and freedom to every household." They leaned heavily into research and design to create a system that easily integrates with up to three heavy loads or subpanels.

When evaluating the FranklinWH, there are various important metrics and technical specifications to keep in mind. Among the most important are the size of the battery (power and capacity), its chemistry, depth of discharge, and roundtrip efficiency.

Size

The aPower comes in one size of 13.6 kilowatt-hours (kWh). Two important metrics to consider when comparing the FranklinWH to other home storage options are power and usable capacity. Power (measured in kilowatts, or kW) can be defined in two ways: peak (maximum) and continuous. Peak or maximum power refers to the maximum amount of electricity that can be output at a single time. In contrast, continuous power is the maximum amount of electricity that can be output consistently. The FranklinWH aPower includes a maximum power rating of 10 kW and a continuous power rating of 5 kW.

Usable capacity (measured in kilowatt-hours, or kWh) measures the maximum amount of electricity stored in your battery on a full charge. The aPower has a usable capacity of 13.6 kWh. The aPower is also modular, meaning you can stack multiple units together if you want an even larger backup capacity. You can stack up to 15 aPower units together, allowing for an overall maximum usable capacity of 204 kWh.

Basic functionality

The functionality of one solar battery next to another can vary; some batteries have excellent off-grid capabilities, while others offer software solutions specific to rate arbitrage. Here are the important qualities of the aPower:

Backup power & load management

The FranklinWH offers safe and reliable backup. It also allows you to dynamically shift loads to maximize your battery's capacity. The aGate includes three smart load circuits, which enable you to remotely turn up to three heavy loads or subpanels on and off.

Chemistry

The aPower is a lithium-ion storage product, specifically, a lithium iron phosphate (LFP) battery. This is one of the most common lithium-ion battery technologies. For a good reason: LFP batteries are known for their high power rating and safety relative to other types of batteries. To learn more about how different lithium-ion battery chemistries stack up against one another, check out our overview of battery chemistry differences.

Outdoor rating

If you're hoping to install your solar battery outside, you'll need to ensure it's weatherproof and has an outdoor protection rating. The aPower is both indoor and outdoor rated and can operate from -4 degrees Fahrenheit to 122 degrees Fahrenheit.

Inverter

Inverters are necessary to convert electricity from direct current (DC) generated by solar panels and stored in solar batteries to alternating current (AC) used by most household appliances. Storage systems can come with or without an integrated inverter – if your system doesn't come with an integrated inverter, you'll have to pair it with a separate, external inverter. The aPower battery comes with a built-in inverter, which can pair with any solar inverter on the market. Note: the inverter for the aPower is only for the battery and not a hybrid inverter to also be used for your solar panel system.

Storage systems can also be either AC- or DC-coupled. While AC-coupled systems are generally easier to install if you're retrofitting your storage system to an existing solar system, DC-coupled systems typically provide higher overall efficiency. The FranklinWH Home Power Solution is AC-coupled.

Performance metrics

Two key ways to evaluate the performance of a solar battery are its depth of discharge and roundtrip efficiency.

Depth of discharge (DoD) indicates the percentage of a battery's energy that has been discharged relative to the battery's overall capacity. Because the useful life decreases each time you charge, discharge, and recharge it, many battery manufacturers specify a maximum DoD level for optimal battery performance. In general, batteries with a higher depth of discharge are considered higher-quality products. The aPower boasts a depth of discharge of 100 percent across all battery sizes, reflective of its safe and advanced LFP battery chemistry.

Roundtrip efficiency measures the electrical losses involved with charging and discharging a particular battery. The higher the percentage, the more efficiently the battery can convert incoming electricity into stored electricity and then into usable electricity. The FranklinWH battery has a roundtrip efficiency of 85 percent; this means that for every 10 kilowatt-hours (kWh) of electricity you put into the battery, you'll receive 8.5 kWh of output.

In most cases, homes with an aPower will charge and discharge their battery every day. So, how long do FranklinWH batteries last? The aPower comes with an impressive 12-year, 6,000 cycles, or 43 MWh throughput warranty (whichever comes first). FranklinWH guarantees that the battery will maintain at least 70 percent of its capacity to hold a charge during that period.

FranklinWH's battery technology is similar to other rechargeable batteries: as time goes on, the battery loses some of its ability to hold a charge. Think of how the battery life of a brand-new smartphone compares to one that is a few years old. As you continually charge and drain your phone's battery, it loses some of its ability to hold a charge.

The battery life of your FranklinWH will deteriorate in the same way, and that isn't an indicator of a product flaw. All batteries lose some of their ability to hold a charge over time after extended usage, whether it's an electric vehicle battery, a home energy battery, or a rechargeable AA battery. This is why FranklinWH offers a warranty that guarantees a certain percentage of storage capacity.

If you want to compare individual battery models side-by-side, our battery Buyer's Guide lets you select products and compare them based on efficiency, capacity, power, and more.

A solar battery installation isn't as simple as a list price for a component – depending on your electrical setup, among other factors, installation costs can vary widely. As an estimate, you can expect the FranklinWH Home Power Solution (including both the aPower and the aGate) to cost about $10,000.

If you want to install the Home Power Solution as part of a solar-plus-storage system, battery costs are just one part of the equation. A 5 kilowatt (kW) solar energy system costs anywhere from $9,000 to $15,000, depending on where you live and the type of equipment you choose.

That may sound like a lot of money, but installing a solar-plus-storage system can be a worthwhile investment. Whether or not the FranklinWH battery makes sense for you is determined by how your electric utility structures its rates and your reasons for installing a solar battery.

In some cases, depending on where you live, you may have access to financial incentives that can reduce your home energy storage installation costs. For instance, if you live in California, you could get a cash rebate covering most of your home battery costs through the Self-Generation Incentive Program (SGIP). Other states (such as Massachusetts) are in the early stages of evaluating battery storage performance incentives as well, and several states already provide cash rebates. You may also be able to participate in a virtual power plant (VPP) aggregation program, in which you get paid to help stabilize the grid. In fact, the FranklinWH Home Power Solution has hardware for future integrations with VPP providers and aggregators.

Whether you want to install an aPower or another home battery pack, you will most likely need to work through a certified installer. Adding energy storage technology to your home is a complicated process that requires electrical expertise, certifications, and knowledge of the best practices required to install a solar-plus-storage system correctly.

A qualified EnergySage-approved company can give you the best recommendation about the FranklinWH battery and other energy storage options available to homeowners today. If you are interested in receiving competing installation quotes for solar and energy storage options from local installers, join the EnergySage Marketplace today and simply indicate any products you're interested in using your profile's preferences section.