10S 10A Charge-Only Bypass BMS

The TorqueBoards 10S Charge-Only BMS is designed for compatible 10-series lithium-ion battery packs using a bypass discharge configuration.

In a charge-only setup, the BMS monitors the individual battery groups, provides 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 design is commonly used in electric skateboard and DIY electric-vehicle battery packs where high discharge current is required, but the BMS is used specifically for charge protection and cell-group management.

Key Features

• Designed for 10S lithium-ion battery packs
• Charge-only bypass configuration
• Maximum charging current: 10A
• Monitors individual series groups through the balance connector
• Supports cell balancing
• Separate P− and B− connections
• Capped NTC lead
• 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 connection 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 each of the 10 series groups

Because the main discharge current bypasses the BMS, the board does not provide main-output discharge protection.

Your battery and vehicle system must use appropriate:

• ESC low-voltage cutoff settings
• Main-output fusing where required
• Proper wire sizing
• Short-circuit prevention
• Battery monitoring
• Safe charging and operating procedures

Specifications

• Battery configuration: 10S
• Battery chemistry: Lithium-ion
• Nominal pack voltage: Approximately 36V
• Maximum charge voltage: 42V
• Maximum charging current: 10A
• Configuration: Charge only / discharge bypass
• Connections: P−, B−, balance connector and capped NTC lead
• Application: Cell monitoring, balancing and charge-side protection

The 20A label is the board’s rated current specification. Recommended maximum charging current is 10A.

Common Applications

This BMS may be used with compatible:

• 10S electric skateboard battery packs
• DIY lithium-ion battery packs
• Modular electric-vehicle projects
• Drift carts and compact EV builds
• Other 10S battery systems using a charge-only bypass configuration

Compatibility depends on the exact 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 10S 10A charge-only bypass BMS
• 1x 10S Balance Wire Harness

Temperature sensors, connectors, chargers and additional wiring are not included unless specifically stated in the selected product option.

Compatibility Requirements

Before installation, confirm:

• The battery is exactly 10S
• The battery uses compatible lithium-ion cells
• The charger output does not exceed 42V
• Charging current does not exceed 10A
• The balance connector and wire sequence match the BMS
• 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 BMS wiring can permanently damage the BMS, battery cells, charger or connected equipment.

Before connecting the BMS:

1. Measure every cell group.
2. Confirm each group is within a safe and similar voltage range.
3. Verify the full pack voltage.
4. Confirm the balance-wire order.
5. Measure sequentially from battery negative to each balance lead.
6. Confirm P− and B− connections.
7. Verify charger polarity and output voltage.
8. Insulate all exposed conductors.
9. Confirm the discharge circuit bypasses the BMS as intended.

Balance-wire voltages should rise sequentially from battery negative. Never plug in the balance connector until the wiring order has been verified with a multimeter.

Important Limitations

Because this is a charge-only bypass configuration, it does not provide main-output:

• Discharge overcurrent protection
• Short-circuit cutoff
• Low-voltage discharge cutoff
• Motor-current management

Do not describe or use it as a full charge-and-discharge BMS when installed in bypass mode.

Safety Information

Lithium-ion battery packs can cause fire, severe 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
• Series and parallel cell groups
• Balance-wire sequencing
• BMS wiring
• Polarity verification
• Insulation and short-circuit prevention
• Proper charger selection
• Electrical testing

Never connect a charger until every wire and voltage has been verified.

Stop using the battery if you detect excessive heat, swelling, unusual odor, damaged cell wrappers, abnormal voltages, repeated imbalance or damaged wiring.