Solar Panel System GuideEnergySage reports that most home battery systems cost about $15,000 for roughly 13.5 kWh of storage before incentives, as of its April 2026 update. The Department of Energy states that storage devices rated 3 kWh or greater are included in the federal solar tax credit. This guide explains what you get for that money and how batteries fit a solar system.
What a Battery Costs
Storage is a substantial add-on to a solar system. EnergySage reports that most home battery systems cost about $15,000 for roughly 13.5 kWh of storage before incentives, based on its April 2026 data.
Capacity varies by product. EnergySage notes the batteries it featured range from 8.8 kWh to 16 kWh, with the Tesla Powerwall 3 offering 13.5 kWh of usable capacity. Larger capacity generally means higher cost and more hours of backup.
Battery Chemistry
Nearly all home batteries share the same base technology. EnergySage states that most home batteries today use lithium-ion chemistry.
Within that category, EnergySage identifies three types: LFP (lithium iron phosphate), NMC, and LTO, with LFP being the most common among its top-rated batteries. LFP is favored for its stability and long cycle life in stationary home use.
Efficiency and Brands
Some energy is lost each time a battery charges and discharges. EnergySage reports roundtrip efficiency ranging from 90% to 98% across the models it featured, which measures the energy retained through a charge and discharge cycle.
The market has several established makers. EnergySage names Tesla, FranklinWH, MidNite Solar, Sigenergy, Enphase, and SolarEdge as the six brands that stood out in its review.
Batteries and the Tax Credit
Storage can qualify for the same federal incentive as panels. The Department of Energy states that energy storage devices with a capacity rating of 3 kilowatt-hours or greater are included in the tax credit.
The Department of Energy's Solar Investment Tax Credit page describes a 30 percent credit for systems installed between 2022 and 2032 under the 2022 law. Federal residential solar tax credit rules changed for systems placed in service after 2025, so that schedule may no longer apply to a new system. Confirm the current credit and your eligibility at IRS Form 5695 and energy.gov before you count on any amount. Because tax rules change, confirm the current percentage and any storage-specific conditions at the DOE source or with IRS Form 5695 guidance before you rely on it.