Home Battery System GuideThe FranklinWH aPower 2 and Generac PWRcell 2 are both marketed for whole-home backup, but they package capacity and power differently. This comparison lists only each manufacturer's published specifications so the numbers speak for themselves.
How to read this comparison
Every figure below comes from the named manufacturer's own product page. The two headline numbers are usable capacity in kilowatt-hours and continuous power in kilowatts. One product is a fixed-size unit while the other is modular within a cabinet, so matching capacities may require different numbers of modules or cabinets.
Be careful comparing a single fixed unit to a configurable cabinet. FranklinWH ships a set per-battery size, while Generac's cabinet capacity varies with how many modules are installed. The fair comparison is at a matched target capacity, not unit to unit.
No winner is declared here. The right pick depends on target capacity, coupling and inverter needs, and installer availability.
FranklinWH aPower 2, from FranklinWH's specs
FranklinWH lists the aPower 2 at 15 kWh usable capacity with 10 kW continuous output, using lithium iron phosphate (LFP) battery technology. It is described as capable of powering an entire home independently or during an outage.
On durability, FranklinWH lists an operating range of -4 degrees F to 131 degrees F, an IP67 rating, and a 30 dBA noise level.
For scale and warranty, FranklinWH lists a maximum configuration of 15 aPower batteries per aGate for 225 kWh of total storage, and a 15-year warranty for 60 MWh of throughput.
Generac PWRcell 2, from Generac's specs
Generac lists the PWRcell 2 as a modular AC-coupled system providing 9 to 18 kWh of storage capacity in a single battery cabinet. Capacity scales with the number of battery modules installed in the cabinet.
On power, Generac lists up to 11.5 kW maximum continuous power, achieved with two PWRcell 2 battery cabinets holding at least seven battery modules in an M4 plus M3 configuration.
For scale, Generac lists the ability to stack two cabinets on a single inverter for up to 36 kWh of storage capacity, and states the single-cabinet capacity is up to 33% greater than the industry-leading battery it references.
Where they differ on paper
On per-unit capacity the two are structured differently. FranklinWH lists a fixed 15 kWh usable per aPower 2 battery, while Generac lists a variable 9 to 18 kWh per cabinet depending on module count. Matching a target capacity therefore involves counting FranklinWH batteries versus Generac modules.
On power, the published continuous figures are close at the top: FranklinWH lists 10 kW continuous per aPower 2, and Generac lists up to 11.5 kW maximum continuous, though Generac reaches that figure using two cabinets with a specific module configuration.
On maximum scale, FranklinWH lists up to 225 kWh across 15 batteries per aGate, while Generac lists up to 36 kWh across two stacked cabinets on a single inverter. Both use lithium-based chemistry, with FranklinWH specifying LFP. The right fit depends on target capacity, coupling and inverter design, and installer support.