BMS 4S 14,4V 40A

The reliable 4S 14.4 V 40 A BMS (Battery Management System) for Li-ion / Li-Po battery packs. The module balances the cells and provides overcharge and over-discharge protection for safer and longer battery life.

Customization

• 4S (14.4V class) e-mobility, UPS, LED, audio and DIY projects
• Electric bicycles/scooters with 4S support equipment, power modules

Main functions

• 4 channel balancing (4S) – reduces cell imbalance during charging
• Protections: overload, over-discharge, over-current and short circuit
• Continuous discharge up to 40 A for reliable operation
• Low internal resistance – more efficient energy release, less heating

Specifications

• Number of cells: 4S (4 cells in series)
• Chemistry: Li-ion / Li-Po
• Nominal voltage: ~14.8 V (often referred to as 14.4 V class)
• Max. Charging voltage: ~16,8 V (4,2 V x 4)
• Continuous discharge: 40 A
• Balancing: passive, 4 channels
• Temperature protection: supported if the model has a sensor

Note: if using LiFePO₄ 4S (nominal ~12.8 V; max ~14.6 V), the following is required LiFePO₄-spec. BMS and charger. This description is for Li-ion/Li-Po 4S.

Installation notes

• Follow the terminal diagram: B-, B1, B2, B3, B4(=B+), P-/P+, C-/C+ (if separated)

• Perform the first start-up without load, check the voltage of each group

• Charge with CC/CV ~16.8 V charger (4S Li-ion)

• Use wires of the appropriate cross-section and insert a fuse in the battery line

FAQ

Is it suitable for 18650/21700 cells?
Yes, if the 4S Li-ion/Li-Po pack is used and the current and heat requirements are met.

Can I charge via the BMS?
Yes, with a 4S Li-ion CC/CV (~16.8 V) charger.

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