One of the most common questions we’re asked is, “Should I install a battery with my solar panel system?”

With rising concerns about power grid outages during extreme weather events, energy storage has become an increasingly important part of the solar equation. Which battery makes the most sense for your situation? In this article, we’ll break down the differences between three popular battery brands — Tesla, Enphase, and Franklin — including their capabilities, availability, and stacking options.

Let’s start with the basics of solar batteries. Simply put, solar batteries store excess electricity generated by your solar panels. That stored energy can power your home when your panels aren’t producing electricity — such as at night or on cloudy days. Batteries can also keep your home running during a power outage.

It’s important to note that in most installations without a battery, your home cannot use the electricity generated by your solar panels when the grid goes down. Because your solar panel system is connected to your utility’s electrical grid, it stops producing energy if the power goes out. This safety mechanism protects utility workers who may be repairing power lines during an outage from the risk of electrocution.

AC-coupled batteries like the FranklinWH aPower 2 and Enphase IQ 10C automatically disconnect your system from the grid when a power outage occurs. They then use the stored battery power—or energy from your solar panels—to supply electricity to your home’s critical loads. This setup allows your system to function as a code-compliant, off-grid solution until the utility restores power.

Another major selling point for solar batteries is the 30% federal solar tax credit, which can be applied toward the final cost of your system.

Tesla Powerwall 3 vs. Enphase IQ 10C vs. Franklin aPower 2

Let’s take a look at each battery and see how they compare. These three batteries share a lot in common: all are AC-coupled or can be integrated with an existing solar system that uses an AC inverter, and all are primarily designed for emergency backup. In addition, all three feature user-friendly apps that allow you to monitor your home energy system in real time and adjust how power is distributed throughout the day.

Tesla Powerwall 3

Tesla has designed this AC battery system for residential and light commercial use. It utilizes a lithium-ion battery that runs much quieter and cleaner than a conventional gasoline back-up generator. There’s no exposed vents that expel heat or visible wires making it a safer solution for households with kids or pets. The Tesla Powerwall 3 is compatible with new and existing solar panel systems. It can also work as a stand-alone home battery without solar panels. Tesla batteries can be installed with most brands of solar panels. You don’t need Tesla solar panels to install a Powerwall.

The Upside: The Powerwall has become the biggest name in solar batteries since launching in 2015.  It sports a sleek design and mounts nicely to the wall.  Multiple Powerwalls can be stacked together to boost storage capacity and power more appliances throughout your home or business. Also, the Powerwall is one of the least expensive solar battery options on the market. Unlike the other two batteries that we offer, the Powerwall 3 can be DC or AC coupled.

The Downside: Its lower price has created a waitlist for the Powerwall.  Depending on when you order one from Tesla, it could take months before your Powerwall arrives.  Also, the Powerwall requires multiple electric boxes and additional parts to meet local electrical codes. These add-ons take up space, limiting your ability to work them into a workable design scheme while leaving you fewer options for concealment.

Here are the Powerwall’s technical details:

The Enphase IQ Battery 10C

Although they are one of the most recognizable brands in the solar industry for their line of microinverters, Enphase also offers an excellent alternative to the Tesla Powerwall. As the company’s fourth generation in its solar battery line, the IQ Battery 10C is becoming increasingly popular with homeowners who want a storage option that easily integrates into their Enphase solar installation.

The Upside: Enphase is one of the most trusted companies in the solar industry. They back up their reputation with one of the best solar battery warranties on the market. The batteries’ lithium iron phosphate chemistry is safer and lasts longer than other competitors. The battery contains four IQ8B microinverters, enabling redundancy—if one fails, others continue to operate—reducing single-point failure risk. With no fans constantly running, this quiet, low-maintenance option mounts on the wall or a pedestal with conduit entry on all sides. The 10C’s modular design makes it easy to add more storage capacity or to stack with up to 4 batteries.

The Downside: At 317 pounds, this Enphase battery is bulkier and heavier than many competitors. It works best when paired with solar modules using Enphase microinverters. Continuous power output is low compared to other similarly sized batteries.

Here are the IQ’s technical details:

The FranklinWH aPower 2

The aPower 2 is FranklinWH’s advanced second-generation home energy battery, designed to store energy from solar panels, the grid, generators, and EVs as part of its integrated energy ecosystem. Franklin designed the aPower 2 with a focus on providing “whole-home backup,” ensuring that property owners maintain power during outages. The battery supports a peak power output of 15 kW and a continuous output of 11.5 kW. The aPower 2 battery will also need to be teamed with a smart energy management unit from Franklin called the aGate. The aGate controls battery charging and power flow in the home. It can be set to charge the batteries from solar, the grid, and even an AC backup generator.

The Upside: You can install up to 15 aPower 2 battery units for a total energy storage capacity of 225 kWh. While this amount of power is more than most homes will ever require, it’s nice to know you have the ability to expand your system with new aPower 2 units as needed. Its AC-coupled design supports microinverters, string inverters, grid, solar, generator, and even emergent EV charging setups.

The Downside: The Franklin whole home backup system is more expensive than some other batteries on the market. Its large form factor may make it a challenge to install in smaller spaces.

Here are the aPower 2’s technical details:

Several variables will factor into which battery will work best for your solar installation. Our consultants can help you choose the right battery option for your solar installation based on price, power needs, maintenance, and longevity.