Autonomous Active Balancer for LTO Cells for 16S DIYBMS All-in-one boards

Project: Autonomous Active Balancer for LTO Cells

Description:

The autonomous active balancer is specifically designed for Lithium Titanate Oxide (LTO) cells with a nominal voltage of 2.3 V and a capacity of 40 mAh. It operates independently, without a microcontroller, ensuring precise and efficient voltage balancing across up to 16 cells in series.

Key Features:

  1. Autonomous Voltage Detection:

• The circuit uses the TL431 precision voltage reference IC to detect overvoltage (>2.3 V) on individual cells.

• No external controller or microcontroller is required.

  1. Capacitive Balancing:

• Excess energy is temporarily stored in capacitors and efficiently transferred to cells with lower voltages.

• This prevents energy loss as heat.

  1. Balancing Current:

• Supports up to 1 A balancing current, ideal for quickly stabilizing small cells like LTO with 40 mAh.

  1. Supports 16 Cells:

• The balancer is designed for up to 16 LTO cells, with a maximum pack voltage of 36.8 V (2.3 V x 16).

  1. Compact Design:

• The PCB matches the dimensions and connections of the DIYBMS V4.90, ensuring easy integration into existing systems.

Technical Details:

• Cell Compatibility: LTO (2.3 V nominal voltage, 2.4 V charge cut-off voltage, 40 mAh capacity).

• Voltage Monitoring: Precisely set to a 2.3 V threshold using the TL431.

• Balancing Technique: Capacitive balancing using 100 µF capacitors (25 V).

• Current Capacity: 1 A per cell.

• Components:

• TL431 (16 units), MOSFETs (16 units), capacitors (16 units), resistor dividers (32 units).

• Mechanical Specifications:

• PCB size: 80 mm x 40 mm.

• Connector positions: Compatible with DIYBMS V4.90.

Advantages:

  1. Efficiency: Minimal energy loss through capacitive balancing.

  2. Autonomy: Operates independently without external control or software.

  3. Flexibility: Compatible with LTO cells and easily adaptable to other cell types.

  4. Simple Integration: Mechanically and electrically compatible with DIYBMS V4.90.
    DIYBMS_LTO_Upgrade_EN_DE.pdf (3.0 KB)