BMS 4S 12V 40A LiFePO4 Battery DALY

The DALY 4S 12V 40A LiFePO4 BMS is a professional-grade Battery Management System engineered specifically for 4-cell series lithium iron phosphate (LiFePO4) battery packs at 12V nominal — the preferred cell chemistry for solar energy storage, marine, RV, electric vehicle, and backup power applications where cycle life, thermal stability, and inherent safety are paramount.

With a continuous discharge current of 40A and a continuous charge current of 40A, this BMS provides balanced protection and charging capability without the mismatch of lower-rated charge-side limitation found in some budget alternatives. The common-port design routes both charging and discharging through the same B− and P− terminals, simplifying wiring in compact battery enclosures and making it plug-and-play compatible with standard inverter-charger setups. A white NTC temperature sensor connector provides onboard thermal monitoring and automatic high-temperature protection.

Built by Dongguan DALY Electronics one of the world’s leading BMS manufacturers this board features the same injection-moulded ABS housing with dustproof, shockproof, and anti-static protection seen across the DALY range. LiFePO4-specific protection thresholds are set at 3.65V ±0.05V overcharge cut-off and 2.5V ±0.05V over-discharge cut-off per cell, matching the precise voltage window of 3.2V LiFePO4 cells. Passive cell balancing ensures all four cells equalise at peak charge for maximum usable capacity and extended cycle life. CE and RoHS certified. Compatible with 26650, 32650, and prismatic LiFePO4 cells.

Specification:

• Brand : DALY (Dongguan DALY Electronics Co., Ltd.)
• Cell Configuration : 4S LiFePO4
• Nominal Pack Voltage : 12V (4 × 3.2V LiFePO4)
• Full Charge Voltage : 14.6V
• Continuous Discharge Current : 40A
• Peak Discharge Current : 80A (1 second)
• Continuous Charge Current : 40A
• Overcharge Cut-off Voltage : 3.65V ± 0.05V per cell
• Over-discharge Cut-off Voltage : 2.5V ± 0.05V per cell
• Cell Balancing : Passive balancing (100mA)
• Temperature Protection : Yes — NTC sensor port
• Short Circuit Protection : Yes (auto recovery)
• Common Port : Yes (charge and discharge share B−/P−)
• Terminals : B− / P− / + / − / NTC
• Sleep Mode Current : < 500µA
• Working Current : < 15mA
• Housing : Injection-moulded ABS (dustproof, shockproof, anti-static)
• Compatible Cell Types : LiFePO4 3.2V (26650, 32650, prismatic)
• Applications : Solar storage, RV / marine batteries, UPS, e-bikes, DIY 12V power wall
• Package Includes : 1 × DALY 4S 12V 40A LiFePO4 BMS, 1 × NTC temperature sensor