1. Product Overview

The DALY 15S 48V 60A LiFePO₄ BMS is designed to manage and protect battery packs containing fifteen LiFePO₄ cells or parallel cell groups connected in series.

A 15S LiFePO₄ battery pack has a nominal voltage of approximately 48V and reaches approximately 54.75V when fully charged at 3.65V per series group.

This BMS supports a rated discharge current of 60A and a charging current of 30A. It features a common-port arrangement, meaning charging and discharging share the same external negative terminal.

The integrated balancing function helps reduce voltage differences between the fifteen series groups during charging. The supplied balance-wire harness allows the BMS to monitor the voltage of each group individually.

2. Technical Specifications

3. Included Components

The product assembly shown includes:

• One DALY 15S 48V LiFePO₄ BMS
• One 15S balance-wire harness
• One heavy-duty black P− cable
• One heavy-duty blue B− cable
• One temperature-sensor lead
• Pre-fitted balance-wire connector

Package contents should be checked against the supplied product before installation.

4. Connection Overview

The balance wires must be connected in the correct voltage sequence. Incorrect wiring can permanently damage the BMS.

5. Protection Functions

The BMS is intended to provide essential protection for a compatible 15S LiFePO₄ battery pack, including:

• Cell overcharge protection
• Cell over-discharge protection
• Discharge overcurrent protection
• Short-circuit protection
• Charge and discharge temperature monitoring
• Individual series-group voltage monitoring
• Cell-voltage balancing
• Charge and discharge switching through internal MOSFETs

Exact protection thresholds, delay times and recovery conditions may vary with the production version. Confirm the required values before using the BMS in a critical application.

6. Cell-Balancing Function

The integrated balancing function helps reduce voltage differences between the fifteen battery groups during charging.

Balancing can help:

• Maintain more consistent group voltages
• Reduce early charging cut-off caused by one high-voltage group
• Improve usable battery-pack capacity
• Support more stable long-term battery performance

Balancing cannot repair damaged, mismatched or severely degraded cells. All cells should be tested and closely matched before assembling the battery pack.

7. Suitable Applications

This DALY BMS may be suitable for compatible 48V LiFePO₄ battery packs used in:

• Electric scooters
• E-bikes
• Electric tricycles
• Solar-energy storage systems
• Portable power systems
• Backup-power batteries
• Robotics projects
• Low-speed electric vehicles
• Industrial battery packs
• DIY 48V LiFePO₄ battery projects
• Battery repair and replacement work

The connected equipment’s continuous and starting current must remain within the verified capability of the BMS, cells, wiring and connectors.

8. Battery and Charger Compatibility

Use this BMS only when:

• The battery contains exactly fifteen LiFePO₄ series groups.
• Each group has a nominal voltage of approximately 3.2V.
• The battery pack has a nominal voltage of approximately 48V.
• The charger is designed for a 15S LiFePO₄ battery pack.
• The charger’s maximum output voltage does not exceed 54.75V.
• The required discharge current does not exceed the verified BMS and battery capability.
• The charging current does not exceed 30A.
• All fifteen battery groups are at closely matched voltages before installation.

Do not use this BMS with a 16S 51.2V LiFePO₄ battery pack. A 16S battery requires a compatible 16S BMS and a different charging voltage.

Do not use it with NMC, NCA or conventional lithium-ion cells because those chemistries use different voltage thresholds.

9. Installation Guidance

• Measure every series group with a multimeter before connecting the BMS.
• Confirm that all fifteen groups have closely matched voltages.
• Connect the blue B− cable to the main battery-negative terminal.
• Connect each balance wire in the correct sequence from battery negative toward battery positive.
• Verify the voltage between every adjacent balance wire.
• Insert the balance connector only after confirming the complete wiring sequence.
• Connect the black P− cable to the negative terminal used by both the charger and load.
• Connect charger positive and load positive directly to the battery-pack positive terminal, according to the applicable wiring diagram.
• Position the temperature sensor where it can accurately monitor battery temperature.
• Use appropriately rated cables, connectors, busbars and insulation.
• Insulate all exposed electrical connections.
• Secure the BMS where it is protected against vibration, moisture and accidental contact with conductive materials.
• Test charging and discharging at a low current before connecting the full load.

Installation should be performed only by a person familiar with lithium-battery wiring and safety.

10. Important Current-Rating Note

The 60A BMS rating does not increase the current capability of the battery cells.

The safe current of the completed battery pack is limited by the lowest-rated component, including:

• Battery cells
• BMS
• Nickel strips or busbars
• Battery cables
• Connectors
• Fuse
• Charger
• Connected equipment

Allow suitable current margin and consider the starting or surge current of motors, inverters and other high-power equipment.

11. Safety Information

• Never connect the balance wires in the wrong sequence.
• Do not reverse the B− and P− connections.
• Do not short the battery or BMS terminals.
• Use only a compatible 54.75V 15S LiFePO₄ charger.
• Do not exceed the BMS charging or discharging ratings.
• Do not install cells with widely different voltages, capacities or internal resistance.
• Use a correctly rated fuse close to the battery-pack positive terminal.
• Protect the BMS against water, conductive dust and loose metal objects.
• Do not use a burnt, cracked, corroded or unusually hot BMS.
• Stop using the battery if it becomes swollen, damaged, excessively hot or produces an unusual smell.
• Confirm the wiring diagram supplied with the exact BMS before installation.