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:
- 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.
- Capacitive Balancing:
• Excess energy is temporarily stored in capacitors and efficiently transferred to cells with lower voltages.
• This prevents energy loss as heat.
- Balancing Current:
• Supports up to 1 A balancing current, ideal for quickly stabilizing small cells like LTO with 40 mAh.
- 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).
- 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:
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Efficiency: Minimal energy loss through capacitive balancing.
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Autonomy: Operates independently without external control or software.
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Flexibility: Compatible with LTO cells and easily adaptable to other cell types.
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Simple Integration: Mechanically and electrically compatible with DIYBMS V4.90.
DIYBMS_LTO_Upgrade_EN_DE.pdf (3.0 KB)