LifePo4 Battery Charger Protection Module (BMS) 4S 30A 12V Common Port with Balancing
Compact 4-series (4S) 12V LiFePO4 battery protection module (BMS), model CF-D34S30A-B, measuring 62 × 45 × 1.5 mm as printed on the PCB. The board combines a common-port charge/discharge path (C- / B- solder pads with exposed tinned traces for high-current wiring), a white multi-pin balance connector carrying the cell taps (B+, B3, B2, B1), twelve onboard MOSFETs with low-resistance R005 (0.005 Ω) current-sensing resistors for the 30 A rating, and a dedicated QFP control IC with a passive balancing network. Four corner mounting holes and an optional switch footprint (marked 开关) complete the layout. Sold as the bare board exactly as pictured.
Features
- 4S LiFePO4 protection – cell tap labels B+, B3, B2, B1 confirm 4-cell series configuration (12V class).
- Common-port design – single
C-terminal pad alongsideB-for charge/discharge return wiring. - 30 A current path – model designation “4S30A”; implemented with 12 onboard MOSFETs and parallel R005 (0.005 Ω) sense resistors.
- Onboard cell balancing – passive balancing network (SOT-23 switching transistors with “102” resistor array) driven by a dedicated QFP control IC.
- High-current solder rails – exposed tinned trace strips on the C- and B- rails for wire soldering / adding solder mass.
- Balance connector – white multi-pin socket for the cell-tap harness (B+, B3, B2, B1).
- Optional switch footprint – pad pair silkscreened 开关 (switch) for an external on/off switch.
- Easy mounting – 4 corner mounting holes; compact 62 × 45 × 1.5 mm green PCB.
- Clear identification – model
CF-D34S30A-Band batch code21K05printed on board for traceability.
Specifications
| Model / Part Number | CF-D34S30A-B (printed on PCB) |
|---|---|
| Board / Batch Code | 21K05 |
| Battery Chemistry | LiFePO4 (Lithium Iron Phosphate) |
| Series Configuration | 4S (4 cells in series) |
| Nominal System Voltage | 12 V |
| Continuous Current Rating | 30 A |
| Port Type | Common port (shared charge/discharge negative, C-) |
| Cell Balancing | Yes – onboard passive balancing network |
| Weight | 15 g |
| Main Terminals | Solder pads C- and B- with exposed tinned traces |
| Cable Length | 35 cm |
| Extra Footprint | Switch pad (marked “开关” / switch) |
| PCB Dimensions | 62 × 45 × 1.5 mm (printed on PCB) |
| Mounting | 4 × corner mounting holes |
| PCB Color | Green |
Applications
- Protection and balancing of DIY or refurbished 4-cell (12V) LiFePO4 battery packs.
- 12V backup/UPS and small solar-storage / solar-lighting battery modules.
- RV, caravan and marine auxiliary 12V lithium packs (within the 30A rating).
- Portable power boxes, LED lighting packs, alarm and backup systems using 4S LiFePO4 cells.
- Replacement protection board for existing 4S LiFePO4 packs where size (62×45 mm) and 30A rating match.
Package Content
- 1 x LifePo4 Battery Charger Protection Module (BMS) 4S 30A 12V Common Port with Balancing
- 1 x Balance harness cable
