• Very low stand-by current: 170uA
• Number of cells: 4 – 16
• One cell voltage: 0.8 – 4.5 V
• Battery pack voltage: DC 9.0 V – 75 V
• Operating temperature: -40°C to +85°C
• Balancing current: 150mA (@4.2V)
• Individual cell voltage measurement resolution: 1mV
• Charge current: 30A continuous; ±750 with external relay / contactor and current sensor
• Discharge/Regen current: ±50 continuous; ±60 continuous (mounted on cool surface); ±150 peak (up 10 sec.); ±750 with external relay / contactor and current sensor
• External temperature sensors measurement resolution 0.1⁰C
• BMS Measurements: 113 x 65 x 12.4 mm
• Weight: 0.193kg (with LEM current sensor)
• HS code: 8537109100

• UART
• USB (with USB-UART cable)
• CAN (with UART to CAN converter) /available below or at checkout/
• Wireless Smartphone connectivity interface (with addition Bluetooth module) /available below or at checkout/

• Cell voltages and temperatures measurement
• Capability to read Enepaq multipoint temperature sensor integrated in battery modules
• Internal battery current measurement (up to 200A)
• External battery current measurement (up to 750A)
• Dissipative balancing up to 150mA
• Protections and warnings adjustable on Control Panel
• Integrated contactor to protect the battery
• External contactor control capability
• Interface that is intended for quick and straightforward connection to a host device (e.g. computer) when configuration, diagnostics, or maintenance is needed (via USB-UART cable) /available below or at checkout/
• CAN connectivity (via UART to CAN converter)
• Capability to log live data from TinyBMS with USB-UART cable.
• Internal TinyBMS events logger for troubleshooting (BMS states, warming and etc.)
• State of Charge (SOC) calculations /SOC-BAR LED available below or at checkout/
• Speed sensor input

The Tiny BMS s516 goes beyond standard features to offer extensive customization possibilities:

• Tailor-made Solutions: Our company provides firmware and hardware customization to perfectly align with your unique project requirements.
• Integrated Power Management: Built-in 150A power switches streamline system design.
• Flexible Connectivity: Supports various communication protocols including UART, MODBUS, CAN, and Bluetooth for easy integration.
• Wide Range Compatibility: Works with 12V to 60V battery systems (4s-16s) and all lithium chemistries.
• Adjustable Parameters: Fine-tune voltage, current, and temperature settings for optimal performance.
• Advanced Features:
  • Dissipative Balancing up to 150 mA
  • Supports up to two external temperature sensors and one dual-range current sensor
  • Event Log and Usage Statistics for in-depth analysis
  • Free Firmware Upgrades to ensure your BMS stays up-to-date
  • Programmable Inputs and Outputs for expanded functionality
• Compact Design: Ultra-compact design (95x65x9 mm and only 97g) maximizes space efficiency in your application.
• Current Sensor Connection: Simplifies integration with external current sensors.

The Tiny BMS s516 is paired with the Battery Insider software, a user-friendly interface that provides comprehensive configuration and monitoring capabilities:

• Configuration:
  • Define cell settings (voltage thresholds, balancing).
  • Set discharge and charge current limits.
  • Program temperature protection.
  • Configure automatic recovery settings.
  • Select BMS operation mode (single port/dual port).
  • Manage external components (charger, load, contactor, temperature sensors).
• Real-time Monitoring: View critical battery parameters like cell voltages, currents, temperatures, and state of charge.
• Data Analysis:
  • Event Logging: Track BMS events and diagnose potential issues.
  • Lifetime Statistics: Gain insights into battery usage patterns.
  • Data Logging: Perform detailed analysis of BMS behavior.
• Firmware Updates: Keep your BMS up-to-date with the latest firmware.

• Battery Lifetime Statistics: The Tiny BMS s516 tracks and stores various statistics over its lifetime. These statistics are apparently non-volatile, meaning the data is preserved even if the battery is disconnected from the BMS.
• Battery Insider Statistics Tab: The Battery Insider software provides a dedicated “Statistics” tab to view these lifetime statistics. The exact data points tracked aren’t mentioned in this excerpt, but the image suggests it might include:
  • Maximum discharge current
  • Maximum charge current
  • Maximum cell voltage difference
  • Under-voltage protection count
  • Over-voltage protection count
  • Discharge over-current protection count
  • Charge over-current protection count
  • Over-heat protection count
  • Charging count
  • Fully charged count
  • Minimum and Maximum pack temperatures
• Clearing Statistics: The BMS allows users to clear all lifetime statistics using the “Clear Statistics” button within the Battery Insider software. It’s important to note that this action permanently erases the data from the BMS memory.

The Battery Insider software is a valuable tool for understanding the long-term health and performance of the battery pack. By monitoring lifetime statistics, users can gain insights into factors like charging cycles, temperature extremes, and potential protection events experienced by the battery pack.

• Cell Settings: The Battery Insider software allows for comprehensive configuration of various cell parameters within the Tiny BMS s516.
• Voltage Cutoff Thresholds: Users can set critical voltage thresholds to prevent over-charging and over-discharging of the battery pack. The software enforces a hierarchy where the Fully Charged Voltage must be within the range of Over-Voltage Cutoff and Fully Discharged Voltage, and the Fully Discharged Voltage must be within the range of Fully Charged Voltage and Under-Voltage Cutoff.
• Charge Finished Current: This setting determines the minimum current at which the BMS considers charging to be complete. Different BMS models and configurations may have limitations on this value.
• Balancing Threshold and Allowed Disbalance: These settings control the automatic cell balancing behavior within the BMS. Cell balancing helps to maintain equal voltages across all cells in the battery pack, thereby extending its lifespan.
• Number of Series Cells: This setting allows the user to configure the BMS for the specific number of series-connected cells within the battery pack.
• Battery Capacity: The user can specify the total capacity (Ah) of the battery pack.
• State-of-Charge (SoC): The Battery Insider software allows for manually setting the estimated remaining capacity of the battery pack.
• Upload to BMS: This button commits all configuration changes from the Battery Insider software to the BMS hardware.
• Safety Settings: The Battery Insider software allows configuration of various safety parameters within the Tiny BMS s516 to protect the battery pack from damage:
  • Over-voltage and Under-voltage Cutoff: These settings define the voltage thresholds at which the BMS will automatically disconnect the battery to prevent over-charging or over-discharging.
  • Discharge and Charge Over-current Cutoff: These settings define the current thresholds at which the BMS will cut off discharge or charging current to prevent excessive current flow. The allowable current limits depend on the specific BMS model, configuration, and current sensor used.
  • Over-temperature Cutoff: The BMS can shut down if the battery pack temperature exceeds the user-defined maximum threshold.
  • Low-Temperature Charger Cutoff: The BMS can prevent charging if the battery pack temperature falls below the user-defined minimum threshold.

• Automatic Recovery: The BMS can automatically recover from warning or fault conditions after a timeout period set by the user. Alternatively, automatic recovery can be disabled, in which case, recovery would require manual intervention (restarting the BMS, connecting a charger, or toggling the ignition signal if enabled).

The Battery Insider software equips users with comprehensive control over the safety features of the Tiny BMS s516, allowing them to optimize protection for their specific battery pack application.

This feature allows you to record BMS data over time for later analysis.

• Data Selection: You can choose which specific BMS data points to include in the log file. The image doesn’t show the available data points, but it likely includes parameters like cell voltages, currents, temperatures, and battery pack voltage/current.
• Logging Interval: This setting determines the frequency at which BMS data is recorded in the log file. It can range from 1 second to 1 hour (3600 seconds).
• Log File Size: This setting defines the maximum size of the log file. The BMS can automatically start a new log file when the current file reaches this size limit. The allowed range is from 2 MB to 1024 MB (1 GB).
• Start Logging from Beginning: When enabled, this option will cause the BMS to start writing data at the beginning of the log file again when it reaches the maximum file size, effectively overwriting the oldest data.
• Start/Stop Logging: These buttons allow you to manually control the logging process. You can start logging data or stop it completely.

Overall, the “Log to file” settings tab in Battery Insider equips users with a valuable tool for capturing BMS data at desired intervals and file sizes. This data can be useful for troubleshooting BMS behavior, monitoring battery health over time, and optimizing performance.

This setting allows you to configure the BMS for either:

• Dual Port operation: This mode uses separate ports for charging (C-port) and discharging (L-port) of the battery pack.
• Single Port operation: In this mode, the same C-port is used for both charging and discharging.

Load and Charger Switch Type: These settings determine how the BMS controls the connection of the battery pack to the load (device using battery power) and charger. You can choose between:

• Internal FET: The BMS uses its built-in FET (electronic switch) to manage connection.
• External relay/contactor: The BMS provides a control signal to an external relay or contactor for switching. This option is only available on high power 150A BMS models.

Ignition Feature (for high power 150A BMS only): This feature allows you to control the BMS based on an ignition signal, potentially from a vehicle. You can set the signal level for ignition on and off.

Precharge Feature (for high power 150A BMS only): This feature enables a pre-charge stage at a lower current before full connection to the load. You can choose to use either the internal FET or an external output pin for pre-charge control.

Charger Detection: This setting allows you to configure how the BMS detects a connected charger. You can choose between:

• Internal detection: The BMS uses its built-in circuitry to detect the charger.
• External input pin: The BMS relies on a signal on a designated pin to determine charger connection.

Speed Sensor Input (optional): This setting enables the BMS to calculate speed (likely for electric vehicles) based on a signal from a speed sensor.

Broadcast Protocol: This setting allows you to configure how the BMS transmits data to other devices. You can choose between:

• CA V3: Used for communication with the Ebike Analyzer Android App.
• ASCII: Broadcasts BMS data in a text format.
• SOC BAR: Used for communication with an LED indicator for displaying the State of Charge (SOC) of the battery pack.

Broadcast: This setting enables or disables the periodic broadcast of BMS data according to the chosen protocol.

Temperature Sensor Type: This setting allows you to select the type of temperature sensor used for monitoring the battery pack.

The Peripheral settings tab in Battery Insider provides comprehensive control over how the Tiny BMS s516 interacts with external components and communicates data. This level of control allows for customization based on the specific application of the battery pack.

Using Battery Management System (Tiny BMS) UART commands it is possible:

• setup all settings
• read back and monitor live data, events, statistics,
• UART communication interface is the main Battery Management System (Tiny BMS) communication, enabled by default
• USB-UART cable to Tiny BMS communication connector and Battery Insider automatically connects to BMS
• wakeup BMS from sleep mode and all other tasks that BMS are intended to do for PC and custom systems.
• Weight: 62 g.
• HS code: 8544429000

USB–UART Communication Cable for Battery Management System (Tiny BMS) includes a single multi-purpose UART interface. In combination with various converters, the interface is compatible with USB, Bluetooth and CAN communication interfaces. Various proprietary commands are available for quick and straightforward connection to a PC Battery Insider application when configuration, diagnostics, or maintenance is needed. Also the main MODBUS protocol commands are supported for rapid integration to existing industrial systems. For more information about communication protocols refer to Battery Management System (Tiny BMS) communication protocols documentation.

UART communication interface is the main Battery Management System (Tiny BMS) communication, enabled by default. Using Tiny BMS UART commands it is possible to setup all settings, read back and monitor live data, events, statistics, wakeup Battery Management System (Tiny BMS) from sleep mode and all other tasks that BMS are intended to do for PC and custom systems. If USB-UART cable is used for Battery Management System (Tiny BMS) connection to a Windows Battery Insider application, it is no need any external steps of configuration, just plug USB-UART cable to Battery Management System (Tiny BMS) communication connector and Battery Insider automatically connects to Battery Management System (Tiny BMS), even if BMS is in deep sleep mode. Tiny BMS USB-UART converter is based on genuine Silicon Labs CP2102 chipset.

All recent Windows operating systems already include the drivers and cable will work straight away. If there is a problem, it is possible to download a driver version that is confirmed as compatible with Battery Management System (Tiny BMS) from Enepaq web store. Alternatively, driver can be downloaded directly from Silicon Labs support website, just make sure to get v6.7.3 or newer if you are running Windows 7 or later OS. When cable is connected, it will appear as a virtual COM port and Battery Insider application will connect to it automatically. When USB- UART communication is not necessary, any other communication module or SOC-BAR LED indicator can be connected to BMS communication interface connector. Only one Battery Management System (Tiny BMS) communication extension module can be connected to Tiny BMS at the same moment.

The USB-UART cable is galvanically isolated. Which gives you additional safety from ground loops and potential damage to equipment.

For higher current capability, external current sensor and contactors should be used. Currently supported current sensor is LEM DHAB S- 133, which is a dual-range sensor, with measurement range up to ±750 A. Lower range measures up to ±75 A and is used for higher accuracy measurement of low current. Switching of ranges is done automatically by Battery Management System (Tiny BMS) itself.

• Weight: 96 g.
• HS code: 9030900000

External LEM DHAB current sensor connector 750A for Battery Management System (Tiny BMS) can hold 150 A discharging current just for very short pulse current spikes (Table 2.1). For higher current capability, external current sensor and contactors should be used. Currently supported current sensor is LEM DHAB S – 133, which is a dual-range sensor, with measurement range up to ±750 A. Lower range measures up to ±75 A and is used for higher accuracy measurement of low current. Switching of ranges is done automatically by Battery Management System (Tiny BMS) itself. External current sensor to Battery Management System (Tiny BMS) system should be connected once at the setup stage of the battery pack.

Note: External current sensor is critical Battery Management System (Tiny BMS) and battery application component. After external current sensor has been connected to Battery Management System (Tiny BMS), BMS must be restarted by the user to confirm that external current sensor is used for battery application, otherwise Battery Management System (Tiny BMS) internal current sensor will be used for current measurement. For complete guide how to properly connect and use external current sensor refer to Chapter 4.

Connector part number, that mates with Battery Management System (Tiny BMS) board is PHR-4 made by JST and connector, that mates with LEM current sensor, part number is 1-1456426-5 made Tyco Electronics. When connecting external current sensor attention must be taken to the positive current direction, providing that high current wire is passed through current sensor in correct direction. Tiny BMS treats positive current from battery positive terminal to load / charger positive terminal.

Note: External current sensor should only be used along with external relay / contactor for load or charger control, when high current capability is needed. When external relay / contactor is used for load / charger switching high current path bypasses the Tiny BMS board and the internal current measurement is not possible.

Battery Management System (Tiny BMS) LEM external current sensor configuration External current sensor can be connected only to the 150 A high power Battery Management System (Tiny BMS) hardware version. Current sensor is the essential component of the battery application, therefore due to the safety reasons there is an important sequence how to connect and use LEM external current sensor.

This Cable Set is Used to Connect the Cells to the Battery Management System (TinyBMS) 750A.

It is Characterized by its Excellent Temperature and Friction Behavior.

• Length: 300mm
• Cross section: 0.35mm²
• Insulation: silicone (well suited for higher currents)
• Connection: JST PH
• Spacing: 2.0mm
• 8-pin cable (2x)
• 9-pin cable (1x)
• 4-pin cable (1X)
• 12-pin cable (1x)
• Weight: 68 g.
• HS code: 8538901900

Battery Management System the Tiny BMS device provides a feature-rich battery management and protection solution for 4-series cell to 16-series cell battery-pack applications. The Tiny BMS (Battery Management System) device has extended firmware features and capabilities, including:

• Fully integrated battery pack manager and protection;
• Low side protection FET drive;
• Integrated cell balancing;
• Ultra low power mode;
• Full array of programmable protection features: voltage, current, temperature;
• Lifetme statistics data monitor and event recorder;
• Supports two external temperature sensor channels and one dual-range current sensor;
• Connectivity: UART, MODBUS, CAN, Bluetooth and BMS data broadcasting;
• Programmable inputs and outputs;
• User-upgradeable firmware for quick updates, bringing bugfixes, new features and other improvements, such as client-specific functionality.

This chapter in detail covers all aspects of Tiny BMS (Battery Management System) firmware features and capabilities. This documentation is based on firmware version BMS.v2.3.241.bms and later releases. The Tiny BMS (Battery Management System) is being constantly improved and evolved, new features are built on top of the base firmware, but the basic protection concept and logic, described in this document, is still the same in the updates.

Please check the User Manual for more detailed information in Chapter 3

Safe and Secure Battery Connection

For safe and reliable operation, it’s crucial to follow the correct sequence when connecting the Tiny BMS s516 to your battery pack. Improper connection can damage both the battery and the BMS. For detailed instructions, please refer to the Tiny BMS s516 manual page 12, paragraph 2.3.2., Tiny BMS battery pack connection sequence. This section outlines the step-by-step process for safe battery pack connection.

Key considerations before using Tiny BMS s516:

Using Tiny BMS device requires at least basic knowledge in electronics and electrical engineering. Enepaq will not be held responsible for damage to the battery or any consequence, if the Tiny BMS device is used improperly and no warranty is provided in such case..

To ensure the security of you and your surroundings, please read these rules and follow all the guidelines contained installation instructions of our Battery Management System (Tiny BMS):

• DO NOT use the system where it may cause interference (eg. medical equipment);
• DO NOT use the system in an explosive environment;
• The system is NOT resistant to the chemical environment and mechanical stress;
• All electrical equipment MUST be rated for the voltage of the battery and battery management system;
• Use double-insulated tools;
• DO NOT short-circuit the battery or battery management system terminals, this could cause the damage to the product or the personal property;
• DO NOT lay tools or metal parts on top of the batteries or near the battery management system cable lugs;
• Before establishing connections, make sure to verify polarity.

This list is not exhaustive, and it is the responsibility of the system designer / installer to conduct their own failure mode analysis and determine what is required.

Working around batteries is DANGEROUS. Risk associated with improper use of the battery with the Tiny BMS device includes: short-circuit, fire or explosion.

Read the ENTIRE documentation to become familiar with the Tiny BMS device and its features before operating. Failure to operate the product correctly and safely may result in damage to the product, personal property and cause serious injury.

Throughout the literature the term “Note:” will be used to indicate procedures which, if not properly followed, create a possibility of physical property damage.