The Home Battery ReportIndependent · No installer money

FranklinWH aPower 2 vs sonnen sonnenCore+

A straight, side by side read on specs and warranties, with the honest caveats. Every figure is from the manufacturer datasheet; sources are at the bottom.

Figure - Specs to scalebars vs the largest in our database
FranklinWH aPower 2 versus sonnen sonnenCore+: specs to scaleHorizontal bars comparing usable capacity, continuous power, peak power, warranty for FranklinWH aPower 2 and sonnen sonnenCore+, each scaled against the largest value in the home battery database.FranklinWH aPower 2sonnen sonnenCore+Usable capacity15 kWh10 kWhContinuous power10 kW4.8 kWPeak power15 kWNot publishedWarranty15 yr10 yr
SpecFranklinWH aPower 2sonnen sonnenCore+
ChemistryLFPLFP
Usable capacity15 kWh10 kWh
Continuous power10 kW4.8 kW
Peak power15 kWNot published
Round-trip efficiency90%85.4%
Warranty15 years or 60 MWh throughput, whichever comes first10 years or 10,000 cycles, covering inverter, modules, cabinet
Backup scopeWhole-home capableWhole-home capable
InverterIntegratedIntegrated

What actually differs

  • More usable capacity: the FranklinWH aPower 2 offers 15 kWh vs 10 kWh, so at that size it carries more of your home for longer per charge.
  • More continuous power: the FranklinWH aPower 2 sustains 10 kW vs 4.8 kW, which matters for running big loads like an AC at once.
  • Longer warranty term: the FranklinWH aPower 2 is warranted 15 years vs 10, though always read the throughput or cycle cap too.
  • Efficiency is not apples to apples here: the FranklinWH aPower 2 quotes 90% (grid to battery to load (AC round trip)) and the sonnen sonnenCore+ quotes 85.4% (max round trip efficiency per SGIP formula), so do not read the raw numbers as a direct ranking.

Which one pays off is a numbers question.

Neither spec sheet tells you the payback in your home. That comes from your rate plan and incentives.

Run the Worth It calculator →

Sources

Source: FranklinWH aPower 2 datasheet, Dec 2025. Specs verified 2026-07-01. Figures are per single unit at beginning of life; confirm the current datasheet with your installer.

Source: sonnen sonnenCore+ technical specifications, 2024 to 2025. Specs verified 2026-07-01. Figures are per single unit at beginning of life; confirm the current datasheet with your installer.