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.
| Spec | FranklinWH aPower 2 | sonnen sonnenCore+ |
|---|---|---|
| Chemistry | LFP | LFP |
| Usable capacity | 15 kWh | 10 kWh |
| Continuous power | 10 kW | 4.8 kW |
| Peak power | 15 kW | Not published |
| Round-trip efficiency | 90% | 85.4% |
| Warranty | 15 years or 60 MWh throughput, whichever comes first | 10 years or 10,000 cycles, covering inverter, modules, cabinet |
| Backup scope | Whole-home capable | Whole-home capable |
| Inverter | Integrated | Integrated |
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 →aPower 2 vs sonnenCore+ FAQ
Is the FranklinWH aPower 2 or the sonnen sonnenCore+ better?
Neither is universally better. The FranklinWH aPower 2 carries more usable capacity (15 kWh vs 10 kWh), while the smaller unit can cost less and fit tighter spaces. The right pick depends on your home's loads, backup needs, and budget, not the brand on the box.
What is the difference in usable capacity between the FranklinWH aPower 2 and the sonnen sonnenCore+?
The FranklinWH aPower 2 offers 15 kWh and the sonnen sonnenCore+ offers 10 kWh of usable capacity.
Which has more continuous power, the FranklinWH aPower 2 or the sonnen sonnenCore+?
The FranklinWH aPower 2 sustains 10 kW continuous vs 4.8 kW, which matters for running big loads like an air conditioner at once.
Which has the longer warranty, the FranklinWH aPower 2 or the sonnen sonnenCore+?
The FranklinWH aPower 2 is warranted 15 years vs 10 for the sonnen sonnenCore+. Read the throughput or cycle cap too, since that can limit coverage before the year count does.
Is the FranklinWH aPower 2 or the sonnen sonnenCore+ cheaper?
Neither spec sheet tells you the installed cost or the payback in your home. That depends on your electricity rate plan and local incentives, so run the numbers for your address rather than comparing sticker prices.
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.