1. Product Overview

The EIK-4S-6235 is a hardware Battery Management System designed for four LiFePO4 cells or parallel cell groups connected in series.

It is marked as a 4S LFP 20A BMS and is suitable for compatible 12.8V nominal LiFePO4 battery packs. A correctly assembled 4S LiFePO4 pack is normally charged to a maximum voltage of 14.6V.

The BMS includes a five-wire cell-sensing harness and a pre-fitted black temperature-sensor lead. Its metal plates protect the electronic components and assist with heat distribution.

2. Technical Specifications

3. Included Components

• One EIK-4S-6235 4S LiFePO4 BMS
• One five-wire cell-sensing harness
• Pre-fitted multi-pin connector
• Pre-fitted temperature-sensor lead
• Metal heat-spreading and protective plates
• Accessible B− and C−/P− power connections

Wire colours and connector positions must be verified before installation. Do not determine the cell-tap sequence solely from wire colour.

4. Main Features

• Designed specifically for 4S LiFePO4 battery packs
• 20A current rating marked on the BMS
• Common charging and discharging negative port
• Individual series-group voltage monitoring
• Temperature-sensing lead
• Plug-in cell-sensing harness
• Metal protection and heat distribution
• Compact internal battery-pack construction
• Suitable for new battery assemblies and compatible repair work

5. Typical Protection Functions

A compatible BMS of this type is intended to manage conditions such as:

• Individual-cell overcharging
• Individual-cell over-discharging
• Excessive discharge current
• Output short circuit
• Abnormal battery temperature

The precise protection voltages, delay times, recovery behaviour, charging-current rating and balancing specifications are not printed on the visible product and should not be assumed.

6. Connection Information

B− Connection

Connects to the main negative terminal of the 4S battery pack.

C−/P− Connection

Common negative connection for the charger and load, according to the marking visible on the BMS.

Cell-Sensing Harness

Connects to the battery negative, intermediate series-cell junctions and battery positive for monitoring the four cell-group voltages.

Before plugging the harness into the BMS, verify every adjacent sensing-wire voltage with a multimeter.

7. Suitable Applications

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

• 12.8V rechargeable battery assemblies
• Solar lighting systems
• UPS and backup batteries
• Portable DC power equipment
• Robotics and automation projects
• LED lighting systems
• Communication equipment
• DIY LiFePO4 battery projects
• Battery repair and replacement applications

Suitability depends on the required charging current, continuous discharge current, starting current and battery-cell capability.

8. Compatibility Requirements

Before purchasing or installing this BMS, verify:

• Battery chemistry is LiFePO4 / LFP
• Battery configuration is exactly 4S
• Nominal pack voltage is 12.8V
• Maximum charger voltage is 14.6V
• Required continuous and peak discharge current
• Maximum charging current
• Cell-sensing connector and wire sequence
• B− and C−/P− terminal locations
• Temperature-sensor requirements
• BMS dimensions and available installation space

This BMS is not suitable for standard 4S lithium-ion, NMC or LiPo packs charged to 16.8V.

9. Installation Guidance

• Match and balance all four cell groups before assembly.
• Measure every cell-group voltage with a multimeter.
• Connect the sensing wires in the correct voltage sequence.
• Connect B− to the battery-pack negative terminal.
• Connect the charger and load negative to C−/P−.
• Use suitably rated wires, terminals and battery interconnections.
• Place the temperature sensor securely against the cells.
• Insulate all exposed terminals and connections.
• Confirm the total pack voltage before connecting the charger or load.
• Use only a charger designed for 4S LiFePO4 batteries.

10. Safety Information

• Incorrect sensing-wire order can permanently damage the BMS.
• Never rely only on wire colour when connecting the harness.
• Do not reverse the battery polarity.
• Do not short-circuit the terminals or sensing wires.
• Never charge a 4S LiFePO4 battery above 14.6V.
• Do not exceed the verified ratings of the BMS, cells or wiring.
• Keep the assembly away from water and conductive debris.
• Do not use the BMS if it is damaged, burnt or unusually hot.
• Installation should be performed by a person familiar with LiFePO4 battery wiring and safety.