Batteries

FranklinWH aPower 2 vs sonnen sonnenCore+ 10

Side-by-side comparison based on specs, real pricing, and our crew's installation experience. Updated for 2026.

Marcus R.Senior Solar Engineer

NABCEP PV Installation Professional·Updated Apr 2026

FranklinWH

sonnen

Choose FranklinWH aPower 2 if:

True whole-home backup with highest capacity (15 kWh)
Homes with high-draw appliances (central AC, well pumps, EV chargers)
Generator integration — seamless hybrid backup
Maximum power output (10 kW continuous, 15 kW peak)

$17,500 installed (with aGate)

7.5

Choose sonnen sonnenCore+ 10 if:

Time-of-use rate optimization (buy low, sell high)
Homeowners who value European engineering and aesthetics
Solar self-consumption maximization
Stackable systems up to 60 kWh

$16,000 installed

Spec-by-Spec Comparison

Specification

FranklinWH aPower 2

sonnen sonnenCore+ 10

Price

$17,500 installed (with aGate)

$16,000 installed

Warranty

15 years

10 years

Usable Capacity

15 kWh

10 kWh

Continuous Power

10 kW

4.8 kW

Peak Power

15 kW (10 sec)

8.5 kW

Round-trip Efficiency

89%

91%

Chemistry

LFP (Lithium Iron Phosphate)

Weight

331 lbs (150 kg)

198 lbs (90 kg)

Dimensions

43.5 x 30.0 x 14.6 in

56.0 x 24.0 x 10.0 in

Operating Temp

-20°C to 55°C

-5°C to 45°C

Connectivity

FranklinWH aGate + Wi-Fi/Ethernet

Wi-Fi / Ethernet

NuWatt Rating

9/10

7.5/10

Pros & Cons

FranklinWH aPower 2

Pros

+15 kWh capacity — largest single residential battery
+10 kW continuous / 15 kW peak — handles heavy loads
+aGate controller manages loads intelligently via app
+IP67 waterproof — install anywhere, indoor or outdoor
+Seamless generator integration for extended outages
+Scales up to 15 batteries per aGate (225 kWh)

Cons

-$17,500 installed — highest total cost (includes aGate)
-aGate required — adds $3,000-4,000 to system cost
-Heavier than competitors at 330+ lbs
-Smaller installer network than Tesla or Enphase

sonnen sonnenCore+ 10

Pros

+10,000-cycle warranty — highest cycle count guarantee
+Three operating modes: TOU, self-consumption, and emergency backup
+All-in-one design with built-in inverter
+German engineering — premium build quality
+Stackable up to 3 units (60 kWh, 14.4 kW)
+Sleek, minimal design blends with modern interiors

Cons

-$1,600/kWh — premium pricing for 10 kWh capacity
-4.8 kW continuous — lowest power output in our lineup
-10-year warranty term — shorter than Enphase and Franklin
-Less common in New England — limited installer experience

Installation Notes from Our Crew

FranklinWH aPower 2

The aPower 2 is our whole-home backup champion. The aGate controller installs next to the main panel and handles automatic load management — it can prioritize circuits and integrate with a generator for extended outages. Total install runs 5-7 hours with a two-person crew. IP67 rating means we can mount it outdoors without a shelter. Best choice when the customer wants to back up everything including central AC and EV charger.

sonnen sonnenCore+ 10

The sonnenCore+ is an all-in-one system — battery, inverter, and energy management in one box. Installs in 3-4 hours with a single crew. It's the lightest battery in our lineup at 198 lbs, making wall mounting straightforward. The TOU optimization mode is excellent for customers on time-of-use rates who want to minimize grid purchases during peak hours. We install these less frequently than Tesla or Enphase, but they're a solid choice for TOU-focused customers.

Frequently Asked Questions

Is the FranklinWH aPower 2 or sonnen sonnenCore+ 10 better?

The FranklinWH aPower 2 scores 9/10 vs 7.5/10 in our rating. It excels at: true whole-home backup with highest capacity (15 kwh). The sonnen sonnenCore+ 10 is the better choice if: time-of-use rate optimization (buy low, sell high). The right pick depends on your specific situation.

How much does the FranklinWH aPower 2 cost vs the sonnen sonnenCore+ 10?

The FranklinWH aPower 2 costs $17,500 installed (with aGate). The sonnen sonnenCore+ 10 costs $16,000 installed. Both prices include professional installation by NuWatt Energy. State incentives may reduce your net cost — use our calculator for exact pricing.

Which has a better warranty?

The FranklinWH aPower 2 has a 15-year warranty (15-year warranty with 60 MWh throughput guarantee). The sonnen sonnenCore+ 10 has a 10-year warranty (10-year / 10,000-cycle warranty with 70% capacity retention). FranklinWH offers the longer warranty.

Does NuWatt install both the FranklinWH aPower 2 and sonnen sonnenCore+ 10?

Yes. NuWatt Energy installs both products and our crew has hands-on experience with each. We can help you choose based on your home, energy goals, and budget during a free consultation.

Can I switch from FranklinWH to sonnen later?

In most cases, yes. Batteries can be added to or replaced in existing solar systems. The main consideration is inverter compatibility and electrical panel capacity. Contact NuWatt for a specific assessment of your system.

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Spec-by-Spec Comparison

Specification

FranklinWH aPower 2

sonnen sonnenCore+ 10

Price

$17,500 installed (with aGate)

$16,000 installed

Warranty

15 years

10 years

Usable Capacity

15 kWh

10 kWh

Continuous Power

10 kW

4.8 kW

Peak Power

15 kW (10 sec)

8.5 kW

Round-trip Efficiency

89%

91%

Chemistry

LFP (Lithium Iron Phosphate)

Weight

331 lbs (150 kg)

198 lbs (90 kg)

Dimensions

43.5 x 30.0 x 14.6 in

56.0 x 24.0 x 10.0 in

Operating Temp

-20°C to 55°C

-5°C to 45°C

Connectivity

FranklinWH aGate + Wi-Fi/Ethernet

Wi-Fi / Ethernet

NuWatt Rating

9/10

7.5/10

Pros & Cons

FranklinWH aPower 2

Pros

+15 kWh capacity — largest single residential battery
+10 kW continuous / 15 kW peak — handles heavy loads
+aGate controller manages loads intelligently via app
+IP67 waterproof — install anywhere, indoor or outdoor
+Seamless generator integration for extended outages
+Scales up to 15 batteries per aGate (225 kWh)

Cons

-$17,500 installed — highest total cost (includes aGate)
-aGate required — adds $3,000-4,000 to system cost
-Heavier than competitors at 330+ lbs
-Smaller installer network than Tesla or Enphase

sonnen sonnenCore+ 10

Pros

+10,000-cycle warranty — highest cycle count guarantee
+Three operating modes: TOU, self-consumption, and emergency backup
+All-in-one design with built-in inverter
+German engineering — premium build quality
+Stackable up to 3 units (60 kWh, 14.4 kW)
+Sleek, minimal design blends with modern interiors

Cons

-$1,600/kWh — premium pricing for 10 kWh capacity
-4.8 kW continuous — lowest power output in our lineup
-10-year warranty term — shorter than Enphase and Franklin
-Less common in New England — limited installer experience

Installation Notes from Our Crew

FranklinWH aPower 2

sonnen sonnenCore+ 10

Frequently Asked Questions

Is the FranklinWH aPower 2 or sonnen sonnenCore+ 10 better?

How much does the FranklinWH aPower 2 cost vs the sonnen sonnenCore+ 10?

Which has a better warranty?

Does NuWatt install both the FranklinWH aPower 2 and sonnen sonnenCore+ 10?

Yes. NuWatt Energy installs both products and our crew has hands-on experience with each. We can help you choose based on your home, energy goals, and budget during a free consultation.

Can I switch from FranklinWH to sonnen later?

Update Location

FranklinWH aPower 2 vs sonnen sonnenCore+ 10

Choose FranklinWH aPower 2 if:

Choose sonnen sonnenCore+ 10 if:

Spec-by-Spec Comparison

Pros & Cons

FranklinWH aPower 2

Pros

Cons

sonnen sonnenCore+ 10

Pros

Cons

Installation Notes from Our Crew

FranklinWH aPower 2

sonnen sonnenCore+ 10

Frequently Asked Questions

Related Comparisons

Not Sure Which to Choose?

Ready to start your clean energy project?

FranklinWH aPower 2 vs sonnen sonnenCore+ 10

Choose FranklinWH aPower 2 if:

Choose sonnen sonnenCore+ 10 if:

Spec-by-Spec Comparison

Pros & Cons

FranklinWH aPower 2

Pros

Cons

sonnen sonnenCore+ 10

Pros

Cons

Installation Notes from Our Crew

FranklinWH aPower 2

sonnen sonnenCore+ 10

Frequently Asked Questions

Related Comparisons

Not Sure Which to Choose?