Guide 2025: BTS battery parameterization on ESI inverters - Modes & Optimization

BTS battery configuration on ESI inverters is one of the most crucial aspects of optimizing your photovoltaic installation. With the right configurations, you can achieve up to 80% self-consumption and considerably reduce your electricity bills. This guide details all the parameterization possibilities between BTS 5K batteries and ESI 3-6K inverters to transform your installation into a truly intelligent energy power plant.

🔋 Compatibility and Technical Specifications BTS E5-20K with ESI

BTS E5 to E20-DS5 batteries are perfectly compatible with ESI 3-6K-S1 hybrid inverters. This technological synergy offers exceptional performance:

• BTS E5-DS5: 5.12 kWh (4.75 kWh usable) - Power 2.5 kW
• BTS E10-DS5: 10.24 kWh (9.5 kWh usable) - Output 5 kW
• BTS E15-DS5: 15.36 kWh (14.25 kWh usable) - Output 7.5 kW
• BTS E20-DS5: 20.48 kWh (19 kWh usable) - 10 kW output

Each system uses LiFePO4 (Lithium Ferrophosphate) technology, guaranteeing over 6,000 cycles and a depth of discharge of 90%. The 400V nominal voltage and 350-425V operating range are perfectly matched to the characteristics of ESI inverters.

⚙️ Basic setting modes: Self-Use and Time-of-Use

Self-Use mode (Optimized Self-Use)

Self-Use mode is the heart of energy optimization. In this configuration, the ESI inverter intelligently manages your BTS battery according to this priority:

1. Production > Consumption: The photovoltaic surplus automatically charges your BTS battery.
2. Production < Consumption: The battery is discharged to supply your equipment.
3. Battery empty + residual need: The inverter draws on the grid only if necessary.

This automatic management allows self-consumption rates of 70% to 85%, depending on your consumption profile.

Time-of-Use mode (peak/off-peak)

For subscriptions with differential tariffs, Time-of-Use mode turns your system into a real tariff optimizer. You can program up to 4 complex rules:

• 📅 Weekly programming: different rules for different days
• ⏰ Multiple time slots: charging during off-peak hours, discharging during peak hours
• ⚡ Power modulation: precise charge/discharge control
• 🎯 Targeted SOC: Desired charge level for each period

🎯 Peak Shaving and Injection Limitation: Advanced Optimization

Intelligent Peak Shaving function

Although not explicitly named "peak shaving", the ESI inverter offers this functionality via Timing mode combined with Feed-in Limit. This configuration allows:

"The programming of precise times and powers to avoid costly consumption peaks, particularly effective for professional installations subject to power tariffs."

Feed-in Limit: Grid Injection Control

The Feed-in Limit function lets you precisely control the power injected into the grid:

• Zero injection: set to 0kW for total self-consumption
• Limited feed-in: Compliance with local technical constraints
• Modular injection: Adaptation to the needs of the grid operator

🔧 Detailed parameter setting via ESI interface

Initial configuration of the BTS Battery

Settings are made via the ESI inverter's advanced menu (password: 0715):

1. Battery Type: Select "BTS 5K".
2. Battery Number: Indicate number of modules installed (1 to 6)
3. Depth of Discharge: Differentiated on-grid/off-grid setting
4. Auto Config Address: Automatic detection in 2-3 minutes

Advanced management parameters

🏠 Operating profiles and recommendations

The Autonomous Home

For a family of 4 with 8000 kWh/year consumption:

• ✅ Recommended configuration: ESI 6K + BTS E15 (15.36 kWh)
• 🎯 O ptimum mode: Self-Use with 90% DOD
• 💰 Expected savings: 70-80% self-consumption

The Professional Optimizer

For tertiary installations with complex pricing:

• ✅ Recommended configuration: Parallel system 2x ESI 6K + 2x BTS E20
• 🎯 O ptimum mode: Time-of-Use + Feed-in Limit
• 💡 Key benefit: Peak shaving and tariff arbitrage

📈 System expansion and scalability

BTS expansion capability

BTS batteries offer exceptional modularity:

• 🔋 Per inverter: up to 6 BTS 5K modules (30.72 kWh)
• 🏭 Parallel system: up to 6 synchronized ESI inverters
• 📦 E xtension kit: Certified cables and accessories included
• 🔧 Progressive installation: Add modules as required

Multi-inverter management

The Parallel Setting function enables the synchronization of multiple ESI inverters with master/slave assignment and automatic addressing. This configuration maximizes available power and system redundancy.

🛡️ Security and maintenance

Integrated safety protocols

BTS-ESI systems incorporate advanced protection :

• 🔒 RCMU integrated into the ESI inverter
• ⚡ IP65 protection for outdoor use
• 🌡️ Thermal management: operation -10°C to +50°C
• 📡 CAN/RS485 monitoring: real-time BMS monitoring

Preventive maintenance

Minimal maintenance guarantees optimum performance:

• 📅 Monthly visual inspection: state of connections and LED indicators
• 🔄 Calibration cycle: Force Full Charge quarterly
• 💻 F irmware updates: Via USB according to evolutions

❓ FAQ - Frequently asked questions

Can I mix different BTS battery capacities?

No, we recommend using identical BTS modules to ensure optimal balancing and maximum system life.

What's the difference between Self-Use and Time-of-Use modes?

Self-Use mode optimizes instantaneous self-consumption, while Time-of-Use allows you to program charging/discharging slots according to electricity tariffs.

How do I activate zero injection mode with my BTS battery?

Activate the "Feed-in Limit" function in the ESI inverter menu and set the value to 0kW. Your battery will then store any surplus not consumed.

How many BTS modules can I connect to an ESI UPS?

Up to 6 BTS 5K modules per ESI inverter, for a maximum capacity of 30.72 kWh per unit. Parallel systems allow much higher capacities.

Ready to optimize your photovoltaic installation? Contact our Wattuneed experts for a personalized sizing of your BTS-ESI system and benefit from precise technical advice to maximize your energy savings.

Wattuneed - Rue Henripré 12, 4821 Andrimont, Belgium - +32 87 45 00 34 - info@wattuneed.com