Heltec 6S LTO Lithium Titanate Battery BMS

Heltec dedicated 6-series battery protection & equalization board, specially designed for LTO lithium titanate batteries and super farad capacitors.

Built with high-precision passive equalization architecture, it supports adjustable single-cell balanced voltage (2.5V ~ 3V wide range), ultra-low static power consumption, stable overcharge/overvoltage protection, and series cascade expansion. It perfectly fits customized low-voltage energy storage packs, automotive start-up power supplies, and capacitor energy storage systems.

🔹 Core Product Parameters 

🔹 Key Features

1. Dual Application Compatibility

   Universally applicable to LTO lithium titanate battery packs and large-capacity farad capacitor energy storage systems, with targeted protection logic for both energy storage devices.

2. Wide Adjustable Balanced Voltage

   Freely modify single-cell protection & equalization voltage within 2.5V to 3V by replacing voltage divider resistors. Complete resistance reference table and online calculation tool provided for easy parameter customization.

3. High Current Passive Equalization

   Built-in 0.7A high-efficiency equalization current, which greatly accelerates voltage balancing of series cells, effectively reduces cell voltage difference, and extends the overall cycle life of the battery pack.

4. Ultra-Low Static Power Consumption

   Only 60μA standby quiescent current, minimal self-consumption for long-term energy storage scenarios, no unnecessary battery drain during idle operation.

5. Expandable High-Power Resistor Interface

   Reserved plug-in resistor holes on the board. Parallel high-power resistors can further increase equalization current, meeting high-speed balancing demands of large-capacity battery packs.

6. Series Cascade Support

   Realize multi-stage battery pack expansion by cascading multiple BMS boards in series, supporting more than 6 series of battery pack protection and equalization.

7. Reliable Circuit Protection

   Stable overvoltage/overcharge protection mechanism, precise voltage sampling, full-channel independent equalization circuit, safe and stable operation.

   

🔹 Advanced Operation Guide

1. Balanced Voltage Adjustment

This board supports flexible voltage customization via replacing precision voltage divider resistors.

• All 6 channels are equipped with 1% high-precision surface-mount resistors. Normally, you only need to replace the marked 18K series resistor to change the balanced voltage.

• Fixed parallel resistor: 220Ω. Enter your target voltage on the official calculation website to get the required resistance value, then replace with a matching 1% precision SMD resistor.

• Adjustable voltage range: full coverage of 2.5V ~ 3V per single cell.

2. Add High-Power Equalization Resistors

Reserved axial plug-in resistor holes on the PCB:

• Hole specification: axial-0.5 package, 0.85mm pad hole diameter, 12.7mm hole spacing, compatible with 1W plug-in resistors.

• Recommended resistance: ~6Ω for 1W color-ring resistors, ~3Ω for 2W color-ring resistors.

• Parallel power resistors to upgrade equalization current; keep proper spacing from SMD resistors for good heat dissipation.

🔹 Wiring & Installation Instructions

1. Wiring Sequence Requirement

   Connect wires strictly in order from battery negative (-) terminal to positive (+) terminal. Confirm wire polarity before power-on to avoid board damage.

2. Farad Capacitor Pre-operation

   Before wiring, fully discharge all capacitors. Short-circuit positive and negative terminals of each capacitor for more than 3 minutes (longer time for larger capacity) to completely release residual power.

3. LTO Battery Pack Assembly

   Ensure excellent consistency of single cells before grouping: low difference in internal resistance and capacity. Pre-select matched cells to maximize the service life of the entire battery pack.

4. Cascade Connection Method

   Realize extended battery strings by cascading multiple BMS boards. Connect the 7th wire of the first board and the 1st wire of the second board to the connection terminal between the 6th and 7th series cell.

🔹 Charge & Discharge Precautions

For Farad Capacitor

Before initial use, pre-charge the capacitor pack to its normal operating voltage. Use a high-power current-limiting resistor during charging to prevent excessive impact current from damaging the power supply.

For LTO Lithium Titanate Battery

• Charging Voltage Limit: For N series battery pack, maximum charging voltage = N × 2.7V. Do not exceed the per-cell 2.7V upper limit. All indicator lights will light up when overvoltage occurs, stop charging immediately.

• Charging Current: Determined by your charger and battery performance, irrelevant to the BMS board.

• First Charge Requirement: Ensure voltage difference between all single cells is within 0.05V before initial charging. Discharge high-voltage cells to consistent level in advance.

• During first charging: pay close attention to board status. When single-cell voltage approaches 2.7V, overvoltage protection indicator will trigger, always monitor corresponding cell voltage.

🔹 Package Contents 装箱清单

• 1 × Heltec 6S LTO BMS Protection Equalization Board

• 1 × Complete 7P Battery Voltage Sampling Connecting Wire Harness