Retrofitting a Balcony Power Plant with Storage: BK215 Installation Guide

Mar 14, 2026

Retrofitting a balcony power plant with storage makes your solar system more efficient and independent. The BK215 from SunLit Solar is a modular solution that integrates seamlessly into existing systems. With Plug & Play technology, users save time and money on expansion.

Market Trends for Balcony Power Plant Storage

The market for balcony solar systems is growing rapidly. According to industry reports, over 500,000 German households installed balcony power plants in 2025, many with storage extensions. Retrofitting balcony power plant storage is becoming a top trend as rising electricity prices promote self-sufficiency.

A balcony power plant with storage optimally combines generation and storage. User profiles show that tenants and homeowners prioritize easy retrofitting. By 2026, experts predict a doubling of storage capacities in private systems.

DRBO Greenenergy pursues a clear goal: to advance the decentralized energy transition together with customers. The company supplies hardware stores, specialist retailers, and installation companies with high-quality solar solutions and now also supports private customers with Plug & Play systems.

BK215 Technical Specifications

The BK215 offers 2.15 kWh capacity and is IP65-certified for indoor and outdoor use. Up to 8,000 charging cycles ensure longevity. Bidirectional inverters like the EV3600 enable EV charging directly from storage.

Modular expansion with up to three B215 units achieves a total capacity of 8.6 kWh. The PV input up to 4 kW supports 10 solar modules of 400 W each. App control optimizes feeding in during the day and night.

Top Products for Retrofitting

Product	Main Advantages	Reviews	Use Cases
BK215 Head Storage	2.15 kWh, Plug & Play, App Control	4.8/5 (Stern-Test)	Expand existing balcony power plants, increase self-consumption
B215 Expansion	Modular stackable, 2.15 kWh per unit	4.7/5 (User Feedback)	Expand capacity to 8.6 kWh, bridge winter months
EV3600 Inverter	Bidirectional, 3600 W	4.9/5 (SunEnergyXT)	Charge EV, grid feeding
Shelly Pro 3EM	Zero-waste strategy, real-time monitoring	4.6/5	Avoid surplus, dynamic feeding

These products are ideal for retrofitting balcony power plant storage. Users praise the simple BK215 installation guide.

BK215 Installation Guide Step-by-Step

Preparation for Retrofitting

Check your existing balcony power plant for compatibility. BK215 is compatible with common micro-inverters up to 800 W. Required tools: safety plug, grounding cable, solar plug wrench.

Plug & Play Assembly

Place BK215 on a stable surface, attach grounding screw.
Plug existing solar cable into INPUT SOLAR of the BK215.
Connect OUTPUT MICROINVERTER to the inverter.
Expansion: Stack B215 modules on top of each other, slide connectors together.
Plug the power cord into a Schuko socket – the system starts automatically.

The BK215 installation takes less than 30 minutes without an electrician. Bypass mode directs surplus power directly to the household grid.

Competitive Comparison BK215 vs. Alternatives

Criterion	BK215 (SunLit)	Anker Solix	EcoFlow River
Max. Capacity	8.6 kWh	5 kWh	3.6 kWh
Modularly Expandable	Yes (3x B215)	No	Limited
Plug & Play	Yes	Partially	Yes
Price per kWh	Favorable	Medium	High
Charge Cycles	8,000+	3,000	6,000
App Control	Full	Basic	Full

BK215 outperforms competitors in flexibility for retrofitting balcony power plant storage.

Core Technology of the BK215

BMS with heating function protects in cold weather. Bidirectional EV3600 efficiently inverts stored power. Zero-waste via Shelly integration minimizes feed-in losses.

Performance parameters: 1920 W output, 100% bypass. Compatible with Deye inverters.

Real-World Use Cases and ROI

A tenant family in Berlin retrofitted an 800 W balcony power plant with BK215. Self-consumption increased from 40% to 85%, annual savings 590 Euros. ROI in 2.5 years.

A homeowner in Munich expanded to 6.45 kWh with 3x B215. Winter production covers 70% of demand, amortization in under 3 years. User: "Child's play, great app."

Buying Guide for Balcony Power Plant Storage

Choose BK215 if you need >2 kWh. Combine with 410 WP modules. Ensure IP65 for balcony. Special offers reduce costs.

Future Trends in Storage Retrofitting

By 2027, experts expect bidirectional charging infrastructure. BK215 remains future-proof with app updates. Microgrids for multi-family homes are booming.

Frequently Asked Questions about BK215 Installation

Is a balcony power plant with storage allowed?
Yes, according to VDE standards, plug & play up to 800 W per phase.

How do I expand the BK215?
Stack up to 3 B215 modules, no wiring required.

Do I need an electrician?
No, the Plug & Play design simplifies retrofitting.

What savings does BK215 achieve?
Up to 590 Euros annually with 2 kWh/day surplus.

Is BK215 weatherproof?
Yes, IP65 for outdoor use with BMS heating.

Does BK215 fit all balcony power plants?
Most micro-inverters up to 1920 W.

Retrofit BK215 now – Next Steps

Calculate system size (consumption x 1.5).
Order complete set with storage.
Install in 30 minutes and configure the app.
Benefit from self-sufficiency – start your energy transition.

Sources

SunLit Solar official product page (BK215 Specifications)
SunEnergyXT User Manual BK215/B215
Stern Comparison Test Balcony Power Plants 2025
OpenELAB Product Description SunLit BK215
Solarprofi-24 Installation Guide PDF
Industry Report Balcony Power Plants Germany 2025 (Statista)
User reviews SunEnergyXT Trustpilot/Facebook

Some of the information in this article comes from the Internet. Product specifications are subject to change. For the latest information, please visit the official website or product page.