DALY Smart Active Balance BMS User Manual

1. Introduction

The DALY Smart Active Balance BMS is designed to optimize battery performance and longevity. In battery packs, individual cells may have slight variations in capacity, internal resistance, and voltage. These discrepancies can lead to overcharging or over-discharging of weaker cells, accelerating degradation and reducing overall pack capacity. A standard BMS often acts merely as a data collector, lacking true management capabilities.

This advanced BMS features a 1A active balancing function, which intelligently redistributes energy from higher-energy cells to lower-energy cells. This process ensures consistent cell performance, extends battery mileage, and prolongs battery life by preventing the vicious cycle of cell degradation.

2. Product Overview and Features

The DALY Smart Active Balance BMS integrates cutting-edge technology to provide robust battery management. Key features include:

Third-Generation Active Balancing: Ensures optimal cell voltage consistency across the battery pack.
Smart Integrated Design: Compatible with 8-24 series battery configurations.
Built-in Bluetooth: Allows for quick and easy viewing and setting of BMS parameters via a mobile application.
High-Performance MOS Tubes: Utilizes TOLL package MOS tubes with low resistance and parasitic inductance, suitable for high-power and high-current applications.
Extensive Peripheral Support: Compatible with a variety of accessories for diverse application scenarios.
IoT Cloud Platform Support: Enables remote monitoring and management of battery data.
PC Host Software: Provides a comprehensive interface for viewing historical data and batch setting parameters.
Professional Wiring Design: Engineered for high-current applications, capable of withstanding significant current impacts.
Comprehensive Protection Functions: Includes overcharge, over-discharge, overcurrent, and short-circuit protection.
Communication Capabilities: Parameters such as over-current, over-discharge, over-temperature, and hibernation can be configured via PC host software or mobile app.

DALY Smart Active Balance BMS models with features — Various DALY Smart Active Balance BMS models (4-24S, 40-500A) highlighting features like Built-in Bluetooth, WiFi, APP support, PC Host, GPS, and IoT Cloud.

3. Specifications

3.1. Basic Specifications

Index	Specification	Remarks
Battery pack type	NCM, LFP, LTO
Number of battery strings	NCM: 8-17S/8-20S LFP: 8-17S/8-24S LTO: 8-17S/8-24S
Cell sampling voltage range	1.5V-4.9V
Operating voltage range	>10V
Balance method	Active Balance
Working power consumption	<1.25W	Idle State
Sleep current	8-17S 35mW, 8-24S 45mW	Idle State
Working Light	Green: works properly Red: Alarm or protection
Product weight	180±5g
Precharge size (uF)	4700, 10000, 22000, 33000	with 25R resistor

3.2. Technical Parameters

Test Content	Default Parameters	Unit	Remark
Rated Discharge Current	40/60	A
Rated Charge Current	40/60	A
Balanced Start Voltage	3.0	V	Can Be Set
Balanced Opening Voltage Difference	≥10	mV	Can Be Set
Balance Current	900±200	mA	Can Be Set
Active Balance Conditions: Balancing activates when both conditions are met: 1) Reaches the set opening voltage. 2) Reaches the set opening voltage difference. If either condition is not met, balancing will cease.

Product Parameters and BMS Dimensions — Detailed product parameters including current, voltage, and balance specifications, along with physical dimensions of various BMS models.

3.3. Protection Parameters

The BMS includes various protection features to ensure safe operation of your battery pack. These parameters are configurable via the mobile app or PC host software.

3.3.1. Single Cell Voltage Protection

Parameter	NCM (V)	LFP (V)	LTO (V)
Over-voltage level 1 alarm	4.1±0.05	3.55±0.05	2.65±0.05
Over-voltage level 1 alarm recovery	4±0.05	3.45±0.05	2.55±0.05
Over-voltage level 1 delay	1±0.8s
Over-voltage level 2 protection	4.2±0.05	3.6±0.05	2.7±0.05
Over-voltage level 2 protection recovery	4.1±0.05	3.55±0.05	2.65±0.05
Over-voltage level 2 delay	1±0.8s
Over-voltage level 3 protection	4.3±0.05	3.8±0.05	2.85±0.05
Over-voltage level 3 protection recovery	4.2±0.05	3.7±0.05	2.8±0.05
Over-voltage level 3 delay	0.5±0.4s
Under-voltage level 1 alarm	2.85±0.05	2.65±0.05	1.85±0.05
Under-voltage level 1 alarm recovery	2.95±0.05	2.75±0.05	1.9±0.05
Under-voltage level 1 delay	1±0.8s
Under-voltage level 2 protection	2.82±0.05	2.6±0.05	1.8±0.05
Under-voltage level 2 protection recovery	2.85±0.05	2.65±0.05	1.85±0.05
Under-voltage level 2 delay	5±0.8s
Under-voltage level 3 protection	2.6±0.05	2.1±0.05	1.8±0.05
Under-voltage level 3 protection recovery	2.7±0.05	2.2±0.05	1.7±0.05
Under-voltage level 3 delay	3±0.8s
Balance ON voltage	3±0.05	3±0.05	2±0.05

Note: Protection and recovery values are configurable; recovery delay parameters are fixed.

3.3.2. Over-Current Protection

Continuous Current	Charging / Discharging Over-Current Value Alarm (Level 1)	Charging / Discharging Over-Current Value Protection (Level 2)	Charging / Discharging Over-Current Value Protection (Level 3)
40A	48±3%A @ Delay 1±0.8s	60±3%A @ Delay 55±0.8s	120±3%A @ Delay 1±0.8s
60A	72±3%A @ Delay 1±0.8s	90±3%A @ Delay 55±0.8s	180±3%A @ Delay 1±0.8s

Note: Parameters are configurable. Over-current protection for charging is released by removing the charger. Over-current protection for discharging is released by removing the load. Release delay is 1±0.8s.

3.3.3. Short Circuit Protection

Test Content	Default Parameters	Unit
Short Circuit Protection Conditions	External load short circuit	A
Short Circuit Protection Delay	10~500	us
Release Condition	Remove Load Release/Charging Release

Note: Short-circuit current values below the minimum or above the maximum may lead to protection failure. It is recommended to test with an air switch for 5 cycles. The short-circuit loop length should not exceed 1.2m, and internal resistance should be below 20mΩ.

3.3.4. Temperature Protection

Parameter	Default (Charging)	Default (Discharging)	Unit
High Temp Alarm (Level 1)	55±3	65±3	°C
High Temp Alarm Release (Level 1)	50±3	60±3	°C
High Temp Protection (Level 2)	65±3	70±3	°C
High Temp Protection Recovery (Level 2)	60±3	65±3	°C
High Temp Protection (Level 3)	75±3	75±3	°C
High Temp Protection Recovery (Level 3)	70±3	70±3	°C
Low Temp Alarm (Level 1)	-10±3	-10±3	°C
Low Temp Alarm Release (Level 1)	-5±3	-5±3	°C
Low Temp Protection (Level 2)	-20±3	-20±3	°C
Low Temp Protection Recovery (Level 2)	-15±3	-15±3	°C
Low Temp Protection (Level 3)	-40±3	-40±3	°C
Low Temp Protection Recovery (Level 3)	-35±3	-35±3	°C
Level 1&2 Temp Alarm & Protection Delay	1±0.8		S
Level 3 Temp Alarm & Protection Delay	0.5±0.4		S

Note: When the trigger condition is met, an alarm or protection will be activated. Alarms do not disable charging/discharging MOS, while protection does. Protection and recovery values are configurable; recovery delay parameters are fixed.

3.3.5. MOS Temperature Protection

Parameter	Default	Unit
High Temp Alarm (Level 1)	90±3	°C
High Temp Alarm Release (Level 1)	85±3	°C
High Temp Protection (Level 2)	100±3	°C
High Temp Protection Release (Level 2)	95±3	°C
High Temp Protection (Level 3)	110±3	°C

3.3.6. Voltage Difference Alarm

Parameter	Default	Unit
Level 1 alarm of excessive differential pressure	0.5	V
Level 2 protection of excessive differential pressure	0.8	V
Level 3 protection of excessive differential pressure	1	V
Level 1 alarm recovery	0.3	V
Level 2 protection recovery	0.5	V
Level 3 protection recovery	0.8	V
Level 1&2 Alarm & Protection Delay	1±0.8	S
Level 3 Alarm & Protection Delay	0.5±0.4	S

3.3.7. Temperature Difference Alarm

Parameter	Default	Unit
First Level Temperature Difference Alarm	10±2	°C
First Level Temperature Difference Alarm Recover	5±2	°C
Second Level Temperature Difference Alarm	15±2	°C
Second Level Temperature Difference Alarm Recover	10±2	°C
Third Level Temperature Difference Alarm	20±2	°C
Third Level Temperature Difference Alarm Recover	15±2	°C
Level 1&2 Temperature Difference Alarm Delay	1±0.8	S
Level 3 Temperature Difference Alarm Delay	0.5±0.4	S

4. Setup and Wiring Instructions

Before installation, ensure you have all necessary components as listed in the packing list. Always take anti-static measures when handling the BMS.

4.1. Packing List

Packing List for DALY Smart Active Balance BMS — The image displays the components included in the package: 1. Smart active balance BMS, 2. P-&-B-cable, 3. Screws, 4. Sampling cable, 5. B+ cable, 6. Key switch cable, 7. NTC, 8. User Manual, 9. Packaging box.

4.2. Interface Pin Instructions

Refer to the table below for detailed pin descriptions for connecting the BMS.

Interface Name	Pin Label	Description
B-interface	B-	Battery negative, connect to battery negative
P-interface	P-	Charge and discharge negative terminal of the BMS
Sampling line interface	B0	Connect to the negative terminal of the first battery
	B1+	Connect to the positive terminal of the first battery
	B2+ to B(last)+	Connect to the positive terminal of subsequent batteries up to the last battery
B+ cable	B+	Connect the last positive battery terminal
NTC-A interface	NTC-1	1# Temperature cable
NTC-A interface	GND	Ground
NTC-B interface	NTC-3	3# Temperature cable
NTC-B interface	GND	Ground
DIO interface	DO	Buzzer output (standard), customizable
DIO interface	GND	Ground
KEY interface	KEY+	Key switch positive
KEY interface	KEY-	Key switch negative
WIFI/GPS/UART/LCD/Power Display Board	3.3V	Power supply 3.3V
WIFI/GPS/UART/LCD/Power Display Board	12V	Power supply 8-12V
UART/RS485/CAN	RX	Communication receiving end
UART/RS485/CAN	TX	Communication sending end

4.3. Wiring Diagrams

The following diagrams illustrate the wiring for various series configurations. Always ensure correct polarity and connections.

Wiring Diagram for 4-8S DALY BMS — Wiring diagrams for 4S, 5S, 6S, 7S, and 8S battery configurations with the DALY BMS.

Wiring Diagram for 8-24S DALY BMS — Wiring diagrams for 20S, 21S, and 24S battery configurations with the DALY BMS.

4.4. Main Wires Description

Wire Name	Default Specification	Optional Specifications
NTC line	28AWG L=250mm GH1.25	L=500mm, L=700mm, L=900mm
CAN/485 line	/	26AWG L=300mm GH1.25
Key line	/	26AWG L=450mm GH1.25
B- line	10AWG L=120±8mm Blue	/
P- line	10AWG L=120±8mm Black	/
B+ line	2Pin_PHB2.0_18AWG_450mm Red	/
Sampling line	8-17S: 1007 24AWG L=450mm (18PIN) Blue 8-24S: 1007 24AWG L=450mm (18+7PIN) Blue	L=600mm, L=800mm

4.5. Wiring Instructions

Sampling Cable Connection: Start with the thin black wire connecting to battery B- (total negative electrode). The second wire connects to the positive electrode of the first battery string. Subsequently, connect the positive electrode of each battery string in sequence. Finally, weld the B+ wire to the positive terminal of the last battery string (total positive pole).
Matching Cables: The cables from different manufacturers are not universally compatible. Always use the matching cables provided by our company.
Anti-static Measures: Take necessary anti-static discharge measures when testing, installing, touching, and using the BMS.
Heat Dissipation: Do not allow the heat dissipation surface of the BMS to directly contact the battery cells. Direct contact can transfer heat to the cells, potentially affecting battery safety.

BMS Connection Diagram with Modules — Diagram illustrating the BMS connection points for various communication and control modules, including LCD, PC Host, Mobile APP, WiFi, GPS, and heating module.

5. Operating Instructions

5.1. Communication Description

The DALY Smart Active Balance BMS supports multiple communication methods for monitoring and control:

UART Communication: The default protocol for direct communication with Bluetooth modules, display screens, and PC host software. Custom communication protocols can also be configured.
RS485 Communication (Optional): For communication with a dedicated host computer via a special communication box. Default baud rate is 9600bps. This allows viewing battery voltage, current, temperature, SOC, and production information, as well as parameter settings and control operations after login. Program upgrades are also supported.
CAN Communication (Optional): Default DALY CAN protocol with a communication rate of 250 kb/s.

5.2. PC Host Software (DALY BMS Tool)

The PC host software provides a comprehensive interface for managing the BMS:

Data Monitoring: Displays real-time data such as voltage, temperature, and configuration values.
Parameter Configuration: Allows setting various parameters for each module.
Production Calibration & BMS Upgrade: Supports calibration of production parameters and firmware upgrades for the BMS.

PC Host Communication and Mobile App Interface — Screenshots showing the PC Host Communication interface and the mobile app interface for monitoring and controlling the BMS.

5.3. Mobile Application (Balance BMS)

The