JIABAIDA ZP04S014-T V1.1 4S 50A 12.8V LiFePO4 BMS with Balance

1. Product Overview

The JIABAIDA ZP04S014-T V1.1 is a 4S 50A battery management system designed for four LiFePO₄ cells or parallel cell groups connected in series.

A completed 4S LiFePO₄ battery pack has a nominal voltage of approximately 12.8V and reaches 14.6V when fully charged. These packs are commonly marketed as 12V LiFePO₄ batteries.

The BMS monitors the four series-connected cell groups and helps protect the battery against unsafe charging, excessive discharge, overcurrent and short-circuit conditions. It also includes a cell-balancing function to help reduce voltage differences between the individual series groups.

This model uses a same-port configuration, allowing charging and discharging through a common controlled negative connection. Its metal-covered construction provides physical protection and helps distribute heat generated by the switching components.

2. Technical Specifications

The exact charging-current limit, balancing current, protection thresholds, delay times and temperature limits are not printed on the visible label and should be verified from the manufacturer’s specification for this exact model.

3. Visible Connection Points

Always confirm the supplied wiring diagram before installation. Do not identify the sensing-wire sequence only by wire colour, connector position or cable length.

4. Protection Functions

The JIABAIDA 4S 50A BMS is intended to provide essential protection for compatible LiFePO₄ battery packs, including:

• Individual monitoring of four series-connected cell groups
• Cell overcharge protection
• Cell over-discharge protection
• Discharge-overcurrent protection
• Short-circuit protection
• Charge and discharge switching through onboard MOSFETs
• Cell balancing
• Temperature monitoring through the NTC connection
• Recovery after supported protection events

A BMS helps protect a correctly designed battery pack, but it cannot compensate for damaged, mismatched, swollen or deeply discharged cells.

5. Suitable Applications

This BMS may be suitable for compatible 4S LiFePO₄ battery packs used in:

• Solar lighting systems
• Small inverter and UPS batteries
• Portable power systems
• Robotics and automated equipment
• Camping and recreational power systems
• Security and surveillance equipment
• Rechargeable LED lighting
• DIY 12.8V LiFePO₄ battery packs
• Battery repair and replacement projects
• Low-voltage backup-power systems
• Compatible mobility and electronic equipment

The continuous operating current and startup current of the connected equipment must remain within the verified capability of the BMS, battery cells, wiring and connectors.

6. Battery and Charger Compatibility

Use this BMS only when:

• The battery contains exactly four series-connected LiFePO₄ cell groups.
• Each cell group has a nominal voltage of approximately 3.2V.
• The completed pack has a nominal voltage of approximately 12.8V.
• The charger is designed specifically for a 4S LiFePO₄ battery.
• The charger’s maximum output voltage does not exceed 14.6V.
• All four series groups are at closely matched voltages before installation.
• The battery cells can safely supply the required current.
• The load’s continuous and peak current remain within the verified limits of the complete battery system.

Do not use this BMS with 4S lithium-ion or lithium-polymer cells rated at 3.6V or 3.7V nominal. Those chemistries require a 16.8V charging voltage and different protection thresholds.

Do not use it as a direct replacement for a lead-acid battery protection circuit without first checking charger and equipment compatibility.

7. Installation Guidance

• Measure the voltage of all four cell groups before installation.
• Confirm the exact sensing-wire sequence from the supplied wiring diagram.
• Connect B− to the battery-pack negative terminal.
• Connect the balance wires sequentially from B0 through B4.
• Connect C− to the common negative terminal used by the charger and load.
• Connect charger positive and load positive directly to battery-pack positive when specified by the wiring diagram.
• Connect the temperature sensor to the designated NTC point.
• Verify the voltage between every pair of consecutive sensing wires before plugging in the balance connector.
• Use correctly sized cables and terminals for the intended current.
• Install a suitably rated fuse close to the battery’s positive terminal.
• Keep soldering or terminal-heating time as short as possible.
• Insulate every exposed electrical connection.
• Mount the BMS where it cannot contact busbars, nickel strips or other conductive parts.
• Allow adequate ventilation and heat dissipation around the BMS.

Incorrect balance-wire order can permanently damage the BMS.

8. Important Current-Rating Note

The advertised 50A rating does not increase the current capability of the battery cells.

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

• Battery cells
• BMS
• Busbars or nickel strips
• Power cables
• Connectors
• Fuse
• Charger
• Connected load

Loads such as motors, pumps and inverters may draw a starting or surge current substantially higher than their normal operating current. Confirm both continuous and peak-current requirements before selecting this BMS.

Adequate cable sizing and heat dissipation are particularly important when operating near the advertised current rating.

9. Safety Information

• Use only with a 4S LiFePO₄ battery pack.
• Use only a compatible 14.6V LiFePO₄ charger.
• Never reverse the battery polarity.
• Never short B−, B+, C− or the cell-sensing connections.
• Do not connect the balance wires in the wrong sequence.
• Do not plug in the balance connector until every sensing voltage has been verified.
• Do not exceed the verified charge or discharge-current rating.
• Use correctly rated cables, connectors and a suitable fuse.
• Keep the BMS away from water, conductive dust and loose metal objects.
• Do not use a damaged, burnt, corroded or unusually hot BMS.
• Stop using the battery if any cell becomes swollen, overheated or abnormally unbalanced.
• Installation should be performed by someone familiar with LiFePO₄ battery wiring and safety.