Home Battery Storage
FranklinWH aPower 2
The largest single-unit residential battery on the market, with an inverter-agnostic hub that works alongside almost any existing solar setup — a strong pick if you value capacity and flexibility over brand recognition.
2 min read
Licensed Electrical Engineer
Overall Rating
4.5 / 5
Price range: $9,000–$12,000 (battery only); $15,000–$20,000 installed with the aGate controller
Pros
- +15 kWh usable capacity — the largest single-unit residential battery from a major manufacturer
- +10 kW continuous / 15 kW peak output, enough to start a 5-ton central AC unit
- +The aGate controller works with virtually any existing inverter brand, not just FranklinWH's own hardware
- +15-year warranty covering 70% capacity retention, matching Enphase's industry-leading term
Cons
- –Less brand recognition than Tesla or Enphase, which can mean fewer installers in some regions
- –AC-coupled design is slightly less efficient than DC-coupled alternatives
- –Can't add capacity in small increments — each additional unit is a full 15 kWh
- –Higher upfront cost than the Powerwall 3 on a per-unit basis, though capacity per unit is also higher
The short version
FranklinWH isn't as well known as Tesla or Enphase, but the aPower 2 has quietly become one of the most-recommended residential batteries among installers in 2026. Each unit stores 15 kWh of usable energy — more than a single Tesla Powerwall 3 (13.5 kWh) and three times a single Enphase IQ Battery 5P (5 kWh) — while delivering 10 kW of continuous power, with a 15 kW peak rating that can start large appliances like a 5-ton central air conditioner.
The system has two parts: the aPower 2 battery itself, and the aGate controller, which manages power flow between solar, battery, grid, and — notably — almost any existing solar inverter brand. That inverter-agnostic design is the aPower 2's biggest practical advantage: unlike the Powerwall 3 or IQ Battery 5P, you don't need to match it to a specific inverter ecosystem.
Where it falls short
Brand recognition is the honest tradeoff. Tesla and Enphase both have larger installer networks, which can mean more competitive labor quotes and easier access to service in some regions — FranklinWH's network, while growing quickly, is still smaller.
The AC-coupled architecture is also slightly less efficient than a DC-coupled design, meaning a small amount more energy is lost in the conversion between solar, battery, and home use compared to some competitors. And like the Powerwall 3, capacity only scales in full-unit increments — there's no way to add a smaller amount of storage than a full 15 kWh.
What it costs
Expect $9,000–$12,000 for a single battery unit, and $15,000–$20,000 for a fully installed system once the aGate controller and labor are included. That works out to roughly $600–$800 per kWh for the battery hardware alone — competitive with, or better than, the Powerwall 3 on a per-kWh basis, given the larger capacity per unit. As of 2026 there's no federal tax credit for standalone battery purchases; state and utility incentives vary by location.
Who it's actually right for
The aPower 2 is a strong choice if you want the largest single-unit capacity available, need an inverter-agnostic system because you already have solar from a different brand, or want whole-home backup — including large appliances — from as few units as possible. It's a slightly less obvious pick if brand-name installer availability in your area, or the absolute longest warranty term, matters more to you than raw capacity.