Enphase IQ Battery: The complete review

Enphase is one of the biggest names in solar inverter technology, and in 2019 the company announced its foray into energy storage with the Enphase Encharge, which was rebranded as the Enphase IQ Battery in 2021.

The Enphase IQ Battery pairs well with solar panel systems, especially if your utility has reduced or removed net metering, time-of-use rates, or demand charges. Installing a storage solution like the Enphase IQ Battery with a solar energy system allows you to maintain a sustained power supply during the day or night as long as you store enough power from your panels when the sun is shining.

As with other battery products, the Enphase IQ Battery is sized for day-to-day use at your home and is often paired with a home 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 electricity stored in your battery instead of having to buy it from your utility company.

Enphase describes the IQ Battery as an "all-in-one AC-coupled storage system." It offers various grid-tied functions, including increasing household solar self-consumption and managing time-of-use (TOU) electricity rates for maximum savings on your electricity bill.

When evaluating solar batteries like the IQ Battery, 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 Enphase IQ Battery comes in two different sizes with different power and usable capacities. Power (measured in kilowatts, or kW) determines the maximum amount of electricity that can be output at a single time, while usable capacity (measured in kilowatt-hours, or kWh) is a measure of the maximum amount of electricity from your battery on a full charge.

The IQ Battery system is also, to an extent, modular, meaning you can add multiple battery products to your storage setup. For example, you might want to install one IQ Battery 10 and an extra IQ Battery 3 to boost your total storage capacity for larger properties with higher electricity needs. Each size also comes in a version that's 40% thinner and 20% wider: the IQ Battery 3T and the IQ Battery 10T.

Think of your battery like water running through a pipe. Energy capacity is the amount of water available to push through the pipe, while power is the size of the pipe itself. Larger pipes allow more water to flow through at once, which depletes the water faster. Similarly, a battery with a high power rating can deliver more electricity at one time but will burn through its available energy capacity faster too.

Enphase IQ Battery power and usable capacity by model

A battery's power determines what appliances you can run with it at once, while usable capacity determines how long those appliances can be run. Batteries with a higher power rating are capable of powering more robust appliances or many appliances at once, while batteries with a higher usable capacity can store more total energy and thus can run your appliances for longer periods of time without needing to recharge.

Basic functionality

The functionality of one solar battery next to another can vary; some batteries boast superior off-grid capabilities, while others offer software solutions for rate arbitrage. Here are some of the most important qualities of the Enphase IQ Battery:

Coupling

The Enphase IQ Battery is an AC-coupled battery; this means that in a solar-plus-storage system, direct current (DC) electricity flows from solar panels to a solar inverter that transforms the electricity into alternating current (AC) electricity. That AC electricity can then flow to your home appliances or go to another inverter that transforms the electricity back to DC for storing in a battery system.

Backup power

The Enphase IQ Battery comes with backup power capabilities. Most solar batteries require an external transfer switch to allow for off-grid operation; however, IQ Battery offers a product called the IQ System Controller 2, which is designed for installation with your Enphase battery system. This component connects your home, the grid, your storage, and your solar energy system all together so that the Enphase IQ Battery system can automatically power your home appliances when the grid goes down.

Chemistry

The Enphase IQ Battery is a lithium-ion storage product; specifically, it is a lithium iron phosphate (LFP) battery. Relative to other types of batteries, LFP batteries are known for their high power rating and safety – to learn more about how different lithium-ion battery chemistries stack up against one another, check out our overview of battery chemistry differences.

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 overall capacity of the battery. Because the useful life of a battery decreases each time you charge, discharge, and re-charge 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 Enphase IQ Battery line of storage products boasts a depth of discharge of 100 percent across all battery sizes, reflective of its safe and advanced LFP battery chemistry.

Roundtrip efficiency is a measure of the electrical losses involved with charging and discharging a particular battery. The higher the percentage, the more efficiently the battery is able to convert incoming electricity into stored electricity and then back into usable electricity. Both batteries in the Enphase IQ Battery line have a roundtrip efficiency of 89 percent; this means that for every 10 kilowatt-hours (kWh) of electricity you put into the battery, you'll receive 8.9 kWh of output.

In most cases, homes with an IQ Battery will charge and drain the battery every day. The IQ Battery comes with a 10-year, or 4,000-cycle, warranty. Enphase guarantees that the battery will maintain at least 70 percent of its capacity to hold a charge during that time period.

Enphase's battery technology is similar to other rechargeable batteries, both large and small: 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 starts to lose some of its ability to hold a charge.

The battery life of your IQ Battery will deteriorate in the same way. That isn't an indicator of a product flaw – all batteries lose some of their ability to hold a charge over time, whether it's an electric vehicle battery, a home energy battery, or a rechargeable AA battery. This is why IQ Battery offers a warranty that guarantees a certain amount 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.

The Enphase IQ Battery is still listed for pre-order only, so exact pricing isn't available yet. Additionally, 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 a rough estimate, you can expect the Enphase IQ Battery 3 to cost between $6,000 and $8,000 and the IQ Battery 10 to cost between $18,000 and $20,000 with a full system installation.

If you want to install the IQ Battery 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 Enphase IQ Battery makes sense for you is determined by the way that your electric utility structures its rates, as well as 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 that covers 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.

The Enphase IQ Battery is currently available through pre-order only. Whether you want to install an Enphase IQ Battery 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 Enphase home battery system 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 near you, simply join the EnergySage Solar Marketplace today and indicate what products you're interested in your profile's preferences section.