12S 50.4V 10A Charge-Only Bypass BMS The TorqueBoards 12S Charge-Only BMS is designed for compatible 12-series lithium-ion battery packs using a bypass discharge configuration. In a charge-only setup, the BMS monitors the individual battery groups, provides cell balancing, and manages the charging path. The battery’s main discharge current bypasses the BMS and connects directly to the vehicle’s power output. This configuration is commonly used in electric skateboard and DIY electric-vehicle battery packs where high discharge current is required, while the BMS is used specifically for charging protection and cell-group management. Key Features Designed for 12S lithium-ion battery packs 50.4V maximum charge voltage Charge-only bypass configuration Maximum charging current: 10A Monitors all 12 series groups Supports cell balancing Separate P− and B− connections Enclosed construction Suitable for electric skateboard and DIY EV battery builds Charge-Only Bypass Configuration This BMS is intended to control the battery’s charging circuit rather than carry the vehicle’s main discharge current. In a typical bypass configuration: B− connects to battery-pack negative P− connects to charger negative Charger positive connects directly to battery-pack positive The vehicle’s main discharge negative connects directly to battery negative The balance connector monitors the 12 individual series groups Because the main discharge current bypasses the BMS, the board does not provide discharge protection for the vehicle’s main power output. The complete battery and vehicle system should use appropriate: ESC low-voltage cutoff settings Main-output fusing where required Correct wire sizing Short-circuit protection Battery monitoring Safe charging procedures Specifications Battery configuration: 12S Battery chemistry: Lithium-ion Nominal pack voltage: 44.4V Maximum charge voltage: 50.4V Maximum charging current: 10A Configuration: Charge only / discharge bypass Connections: P−, B− and balance connector Application: Cell monitoring, balancing and charge-side protection Common Applications This BMS may be used with compatible: 12S electric skateboard battery packs DIY lithium-ion battery packs Modular electric-vehicle projects Drift carts and lightweight EV builds Other 12S battery systems using a charge-only bypass configuration Compatibility depends on battery chemistry, series count, charger voltage, charging current, balance-wire order and complete battery architecture. Connection Overview B−: Connects to the main negative terminal of the battery pack. P−: Connects to the negative side of the charging port or charger circuit. Battery positive: In a typical charge-only setup, charger positive connects directly to pack positive. Balance connector: Connects to the battery’s individual series groups in the correct sequential order. NTC: The NTC lead is capped and not used in the standard TorqueBoards bypass configuration. What’s Included 1x 12S 10A charge-only bypass BMS 1x 12S Balance Wire Harness Balance-wire harnesses, chargers, charging ports, connectors and additional wiring are not included unless specifically stated. Compatibility Requirements Before installation, confirm: The battery is exactly 12S The battery uses compatible lithium-ion cells The charger output does not exceed 50.4V Charging current does not exceed 10A The balance connector matches the BMS Balance-wire sequence is correct P− and B− are wired correctly The main discharge path bypasses the BMS The complete system includes appropriate discharge-side protection Do not use this BMS with a different series count or incompatible battery chemistry. Installation and Verification Incorrect wiring can permanently damage the BMS, cells, charger or connected electronics. Before connecting the BMS: Measure every cell-group voltage. Confirm all groups are within a safe and similar voltage range. Verify the complete pack voltage. Confirm the balance-wire sequence. Measure sequentially from battery negative to every balance lead. Confirm the P− and B− connections. Verify charger polarity and output voltage. Insulate all exposed conductors. Confirm the vehicle discharge circuit bypasses the BMS. Never connect the balance plug until every balance-wire position has been verified with a multimeter. Important Limitations When installed as a charge-only bypass BMS, it does not provide main-output: Discharge overcurrent protection Short-circuit cutoff Low-voltage discharge cutoff Motor-current management Do not use or describe this as a full charge-and-discharge BMS when wired in bypass mode. Safety Information Lithium-ion battery packs can cause fire, serious injury or property damage if incorrectly assembled, wired, charged, damaged or serviced. Installation should only be completed by someone experienced with lithium-ion battery architecture, polarity verification, balance-wire sequencing, BMS wiring, insulation and short-circuit prevention. Never connect a charger until every connection and voltage has been verified.