This document describes the WATTSTUNDE Nova-Series Lithium-Iron-Phosphate (LiFePO4) battery, a versatile energy storage solution designed for both stationary and mobile applications. The battery is engineered to provide a nearly constant voltage, ensuring reliable operation of connected consumers across its entire capacity range. It offers significant weight advantages and additional energy reserves compared to conventional lead-acid or gel batteries. An integrated Battery Management System (BMS) continuously monitors the battery to ensure optimal performance and longevity.

Function Description:

The WATTSTUNDE Nova-Series LiFePO4 battery serves as an energy storage device, suitable for various applications such as service and on-board batteries in recreational vehicles, or as solar energy storage. It is not intended for use as a starter battery due to the significantly higher starting current required by vehicle starter motors. The battery is immediately ready for use upon delivery and does not require prior activation, as its terminals are always live.

The integrated Bluetooth 5.0 interface allows for convenient monitoring of the battery status via a smartphone or tablet using the WATTSTUNDE Nova APP. This eliminates the need for complex external battery monitors, providing all essential data about the battery and its individual cells directly on the user's mobile device. The app displays the state of charge (SoC), current voltage, current, number of cycles, and current capacity, among other values. It also provides cell voltage information for each individual cell within the battery, along with warning messages, errors, and cell health status. The app allows users to view historical charge and discharge data under the "Statistics" tab. Furthermore, the app enables users to adjust settings such as language, password, battery name, and to set the wiring type for connected batteries, providing an overview of the current wiring configuration.

The battery can be connected in parallel or in series, but not in a mixed parallel and series configuration. A maximum of four batteries can be connected together. When connecting multiple batteries, it is crucial to ensure they are of the same age, model, manufacturer, and state of charge. The voltage difference between interconnected batteries must not exceed 0.1V. Before connecting, the voltages of all batteries must be equalized by fully charging them and then measuring their voltages with a multimeter, recharging any battery with a voltage difference greater than 0.1V until all batteries have the same state of charge.

The battery supports fast charging, significantly reducing the time required for connection to the mains. It does not suffer from a memory effect, meaning it does not always need to be fully charged; in fact, its service life can be extended by not always charging it to 100% SoC. The integrated BMS automatically balances the cells when necessary.

Important Technical Specifications:

While specific numerical values are referred to in the manual as being in a "data sheet," the general technical specifications described include:

Battery Type: Lithium-Iron-Phosphate (LiFePO4).
Voltage: Can be used with 12V/24V consumers or inverters (series-dependent). When connected in series, configurations of 24V, 36V, and 48V are shown.
Bluetooth: Integrated Bluetooth 5.0 interface for wireless monitoring via the Nova APP. The connected smartphone must support at least Bluetooth 5.0.
Dimensions: Similar to common AGM, lead-acid, or gel batteries, with DIN dimensions allowing for a wide range of applications.
Charging Characteristic: Recommended 3-stage CCCV (Constant Current, Constant Voltage) chargers with a lithium charging characteristic and a suitable cut-off voltage for optimal longevity.
Operating Temperature: Charging and discharging should only occur within the specified temperature range. Storage temperature is recommended at 18°C - 25°C.
Maximum Connections: A maximum of 4 batteries can be connected in parallel or series.
Voltage Difference for Multi-Battery Systems: The voltage difference between interconnected batteries must not exceed 0.1V.
Cable Requirements: Always use cables of the same length, type, and cross-section for parallel and series connections. Recommended cable cross-sections are between 50mm² and 90mm² depending on the model and wiring.
Safety Features: Integrated BMS for constant monitoring and cell balancing. Protection against deep discharge.
Certifications: RoHS Compliant (2002/95/EC). CE marking.
Transport Classification: UN3480, Class 9, Packing Group II, compliant with ADR, RID & IMDG (P903) for land/water transport and IATA (P965) for air transport.

Usage Features:

Easy Replacement: The battery's dimensions are similar to common lead-acid battery types, often allowing for direct replacement without modifying existing battery holders or charging structures.
Versatile Applications: Suitable for stationary operation (e.g., solar energy storage) and mobile use (e.g., service/on-board battery in recreational vehicles).
APP Monitoring: The WATTSTUNDE Nova APP provides comprehensive real-time data on battery status, including SoC, voltage, current, temperature, cycle count, and individual cell voltages.
Parallel and Series Connection: Allows for flexible system configurations to achieve higher voltages or capacities, provided all connected batteries are identical and properly equalized.
Fast Charging Capability: Reduces charging times, enhancing convenience.
No Memory Effect: The battery does not need to be fully charged every time, which can even extend its service life.
Automatic Cell Balancing: The integrated BMS ensures that cells are automatically balanced, optimizing battery performance and longevity.
Safety Precautions: Emphasizes the importance of correct polarity, proper fastening, using insulated tools, and protecting connections with fuses to prevent short circuits. Warns against opening the battery housing, as this voids the warranty.
Load Management: Advises caution with inductive loads that have high starting currents, as these can damage the battery if they exceed the maximum permissible discharge current. Users are advised to consult the manufacturer's instructions for connected devices.

Maintenance Features:

Cleanliness: Keep the connection terminals and the battery surface clean.
Tight Connections: Ensure terminals are securely tightened to prevent increased contact resistance and potential fire hazards from loose connections.
BMS/Bluetooth Reset: In the unlikely event of a BMS or Bluetooth module malfunction, a "Restart button" can be used to reactivate them. Users are warned that APP settings might be lost during this process.
Regular Charge Level Check: Especially during winter breaks or extended storage, the charge level should be checked regularly, and the battery recharged if necessary, according to the individual data sheet's recommendations.
Calibration: Regular use helps maintain capacity and calibrate the charge status. If a SoC error occurs, it is recommended to discharge the battery to approximately 10% SoC and then fully charge it to 100% SoC, repeating this process multiple times if needed.
Proper Storage: Disconnect all devices and store the battery in a well-ventilated room at 18°C - 25°C, away from direct sunlight. The optimal storage capacity is 70% SoC.
Log File Download: In case of a malfunction or failure, a remote diagnosis can be performed by downloading and providing the battery's log file via the Nova App. The downloaded file is encrypted and can only be analyzed by WATTSTUNDE service personnel.
Disposal: Electronic waste must not be disposed of with household waste but should be recycled at appropriate collection points.

wattstunde Nova Series - Page 2

Table of Contents