High-Voltage Stackable Lithium Battery System
Polinovel HSTK Series is a high-voltage LiFePO₄ battery system, designed for residential solar energy storage and light commercial applications. Each modular unit delivers 25.6–40.9 kWh of energy at nominal voltages from 256 V to 409.6 V, and multiple units can be stacked to scale capacity up to 50 kWh per system. This high-voltage solution ensures exceptional safety, flexible expansion, and seamless integration with your solar setup.
Optimized for Your Energy Needs
Save Time on Installation
Modular, stackable design enables quick plug-and-play setup with minimal wiring. It shortens installation time and lowers labor costs for faster project delivery.
Store More Solar Energy
High-voltage modules with expandable capacity up to 50 kWh increase system scalability and storage density, ensuring longer backup and better solar utilization.
Protect System Reliability
Automotive-grade LiFePO₄ cells and advanced BMS provide multi-layer protection, ensuring stable operation, extended battery life, and reduced maintenance.
Monitor & Control Easily
Built-in CAN communication enables seamless integration with inverters and EMS, allowing real-time monitoring and smart energy optimization.
Specification
| Model | HSTK25 | HSTK30 | HSTK35 | HSTK40 |
| Nominal Voltage | 256V | 307.2V | 358.4V | 409.6V |
| Nominal Capacity | 100Ah | 100Ah | 100Ah | 100Ah |
| Energy | 25.6kWh | 30.7kWh | 35.8kWh | 40.9kWh |
| Charge Cut-off Voltage | 290V | 350V | 408V | 467V |
| Discharge Cut-off Voltage | 212V | 254V | 296V | 340V |
| Standard Charge Current | 50A | |||
| Max. Charge Current | 100A | |||
| Max. Constant Discharge Current | 100A | |||
| Scalability | Up to 10pcs * 51.2V 100Ah to reach 50kWh | |||
| Communication | CAN | |||
| Dimension | 650*400*1020mm (25.6*15.7*40.2in) |
650*400*1178mm (25.6*15.7*46.4in) |
650*400*1336mm (25.6*15.7*52.6in) | 650*400*1494mm (25.6*15.7*58.8in) |
| Weight | 280kg (617lbs) | 330kg (728lbs) | 380kg (838lbs) | 430kg (948lbs) |
| Charge Temperature | 0~50 °C | |||
| Discharge Temperature | -15~60°C | |||
Listed by Leading Inverter Brands
Our batteries are officially listed as compatible by several globally recognized inverter manufacturers. Each product has undergone rigorous testing and validation to ensure seamless communication, reliable operation, and full compatibility across diverse inverter platforms.
The Energy Challenge
Rising electricity costs, increasing grid interruptions, and underutilized solar assets are creating new challenges for businesses. Even advanced solar arrays may be delivering only a fraction of their potential value.
Rising Costs
Electricity bills continue to increase, putting pressure on household and business budgets. The gap between peak and off-peak rates is widening, making traditional energy consumption more expensive.
Grid Reliability
Power interruptions are becoming more frequent due to extreme weather and aging infrastructure. These outages can lead to significant operational disruptions and financial losses.
Solar Value Gap
Solar panels produce maximum energy during midday, while business energy demand often peaks in the late afternoon or evening. Excess generation is frequently sold back to the grid at rates far below peak consumption costs, limiting the return on your solar investment.
The Polinovel HSTK Series Solution
The Polinovel HSTK Series addresses this fundamental disconnect between energy generation and consumption. It's a high-voltage battery storage system that turns your solar investment into a 24/7 power asset, cutting your reliance on expensive grid electricity while providing backup power when you need it most.
Key Features & Benefits
The HSTK Series is a modular, high-voltage lithium battery system built for residential and light commercial energy storage.
High Capacity
Available in 25.6 kWh to 40.9 kWh configurations, designed to keep critical systems operational during outages.
High Voltage
Operates at 256V to 409.6V, delivering cleaner power through your existing inverter with minimal conversion losses.
Scalable
Modular design supports expansion-connect multiple units to meet growing energy requirements, up to 50 kWh.
Reliable
Automotive-grade manufacturing standards ensure reliable performance even in extreme conditions.
High Efficiency
Intelligent management optimizes energy use, delivering high overall efficiency compared to conventional systems.
Wide Temperature Range
Charge: 0–50 °C | Discharge: -15–60 °C, ensuring performance across diverse environments.
Smart Management
CAN communication enables intelligent charge/discharge control, extending battery life and improving operational efficiency.
Plug-and-Play
Modular design allows easy installation and expansion without complex wiring changes.
Energy Savings Comparison
Significant Cost Reduction
Store low-cost off-peak or solar energy and deploy it during peak hours-businesses can achieve:
Energy Cost Savings 40-60%
Solar Utilization 85-95%
Peak Demand Reduction 60-75%
How It Solves Real Challenges
The HSTK Series addresses critical energy management challenges with innovative technology and intelligent design.
Intelligent Power Management
The integrated high-voltage control box acts as the system's brain. It continuously monitors each battery module's voltage, temperature, and state of charge, then communicates with your inverter in real-time to optimize charging and discharging.
Round-trip efficiency: up to 96%
Effortless Modular Expansion
Unlike conventional systems that require manual wiring adjustments, the HSTK Series adopts a modular plug-and-play design. Capacity can be expanded simply by connecting additional units in series-no complex reconfiguration required.
Scalable capacity: up to 50 kWh
Peak Demand Optimization
For commercial users impacted by demand charges-costs based on the highest short-term power draw-the HSTK system mitigates peaks by supplying stored energy during load spikes.
Weather-Resilient Operation
With an operating range of –15 °C to 60 °C, the system ensures stable performance under both freezing and high-heat conditions. Integrated heating modules safeguard operation in cold climates, supporting consistent year-round reliability.
Energy Flow Visualization
Solar Panels
Generate electricity during daylight hours
Battery Storage
Stores excess energy for later use
Home/Business
Uses stored energy during peak hours
Cost Savings
Reduces electricity bills by 40-60%
During daylight, solar panels produce electricity that powers your operations. Any surplus energy is stored in the HSTK battery system rather than sold back to the grid at lower rates. During peak periods, stored energy is deployed to meet demand, reducing exposure to high electricity prices and lowering operational costs.
Real-World Applications
The HSTK Series strengthens energy resilience and optimizes cost efficiency across diverse residential and commercial environments.
Suburban Residential
Homes equipped with rooftop solar often face a mismatch between daytime generation and evening consumption. The HSTK Series captures surplus solar energy and stores it for use during peak tariff periods, increasing self-consumption and significantly reducing grid purchases. Its 25–40kWh capacity range supports several hours of evening household load, helping homeowners maintain comfort and stability even during outages or high-demand periods.
Farm Operation
Modern farming relies heavily on electrically driven irrigation systems, greenhouse controls, ventilation, and water pumps-all of which are vulnerable to grid instability. The HSTK Series delivers consistent, high-voltage power to ensure continuous operation during outages or voltage fluctuations. By maintaining critical equipment uptime, the system helps reduce operational risk, protect crop performance, and support predictable agricultural output throughout the growing season.
Medical Clinic
Healthcare and community facilities require stable, uninterrupted electricity for vaccine refrigeration, monitoring equipment, communications, and essential digital systems. The HSTK Series provides a dependable, low-maintenance power reserve that activates when grid supply falters, reducing reliance on noisy, fuel-dependent generators. Its high-voltage design ensures smooth transitions and stable output, safeguarding sensitive medical assets and improving overall service continuity.
Small Manufacturing
Production environments such as workshops, fabrication centers, and precision machining facilities are highly sensitive to voltage fluctuations and short-duration outages. Even brief interruptions can halt machines, trigger recalibration procedures, and cause avoidable production delays. The HSTK Series stabilizes power quality and supplies the necessary backup energy to keep equipment running without disruption. This helps maintain workflow continuity, protects machinery, and supports more consistent overall productivity.
Investment Analysis
Understand the financial benefits and return on investment of the HSTK Series battery system.
Total Cost Structure
Battery System: varies by capacity
Installation Labor: moderate additional cost depending on site
Electrical Upgrades (if needed)
Monitoring and Control Integration: included
Annual Operating Costs
Monitoring Platform Fees: small recurring fee
Control System Electricity Overhead: minimal
Available Incentives
Federal and regional incentives may apply (e.g., tax credits, rebates) to reduce total system investment
Eligibility and amounts vary by region and installation type
Return on Investment
Residential
Multi-year payback possible depending on electricity rates, load profile, and solar integration.
Commercial Example
Shorter payback is typical due to higher energy consumption and demand charges.
System Lifespan
16+
Years of Useful Service
Based on 6,000 charge/discharge cycles
System Comparison
| Feature | HSTK Series | Low-Voltage Systems | Generator Backup | Grid-Only Operation |
|---|---|---|---|---|
| Initial Cost | Higher | Medium | Lower | None |
| Operating Costs | Very Low | Low | High (fuel, maintenance) | Highest (electricity bills) |
| Efficiency | 94-96% | 85-88% | 20-35% | N/A |
| Noise | None | None | High | None |
| Emissions | Zero | Zero | High | Depends on grid |
| Response Time | Instant (<20ms) | Fast | Slow (10-30 seconds) | N/A |
| Maintenance | Minimal | Moderate | High | None |
| Scalability | Excellent | Limited | Very Limited | N/A |
| Long-term Value | Excellent | Good | Poor | Very Poor |
Warranty and Support
We stand behind our products with industry-leading warranty coverage and support services.
Industry-Leading Warranty
The system carries a 5-year warranty covering manufacturing defects and battery performance (minimum 80% capacity retention under specified operating conditions).
5-year standard warranty
Extended warranty options
Minimum 80% capacity retention guarantee
Covers all manufacturing defects
Comprehensive Support
Our technical support team is dedicated to ensuring your system operates at peak performance throughout its lifespan.
Dedicated technical team ensuring timely response to system issues
Remote diagnostics for 90% of issues
Ongoing firmware updates for product life
Frequently Asked Questions
What maintenance is required for the HSTK Series?
Maintenance requirements are minimal: Quarterly visual inspections for loose connections or unusual signs, and annual professional inspection recommended but not strictly required for warranty coverage. The battery management system handles cell balancing automatically.
Is the HSTK Series compatible with my existing solar system?
The HSTK Series is compatible with most current hybrid inverters from major manufacturers (Goodwe, Deye, Growatt, Solis) through standard CAN communication protocols. If you're upgrading from a standard solar installation, verify inverter compatibility before purchasing.
Can I expand the system later?
Yes, the HSTK Series uses a modular architecture where additional units connect in series with simple plug connectors. Each module is a complete battery with its own management system. Upgrading your system is as simple as adding the appropriate modules and updating the configuration.
How long does installation take?
Typical installation timeline for a residential setup: 4-6 hours with a qualified electrician. This includes physical mounting, electrical connections, and inverter configuration. Commercial installations may take longer depending on complexity.
How does the system perform in extreme temperatures?
The system operates reliably in a wide temperature range: -15°C to 60°C. In winter, the built-in heating function maintains minimum cell temperature for charging, drawing less than 200W. This allows morning solar charging even when overnight temperatures dropped below freezing.
What happens during a power outage?
During a power outage, the system seamlessly transitions from grid to battery power in near-instantaneous enough that computers stay on and refrigeration doesn't skip a beat. The system will provide backup power for essential loads based on your configured settings.
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