Why does the battery stop working a few seconds after a high current draw?

A battery stopping to work shortly after a high current draw can be attributed to several factors, often related to the battery’s internal chemistry, capacity, or external conditions.

Here are some potential reasons:

1. Voltage Sag:

   • During a high current draw, especially if it exceeds the battery’s recommended discharge rate, the voltage may sag significantly. If the voltage drops below a certain threshold, electronic devices may shut down or the battery protection circuit may activate, interrupting the power supply.

2. Overcurrent Protection:

   • Many batteries are equipped with protection circuits to prevent damage from overcurrent. If the current draw surpasses the battery’s designed limits, the protection circuit may activate and temporarily disconnect the battery to avoid overheating or damage.

3. Capacity Limitation:

   • The battery might have a limited capacity or insufficient energy to sustain a high current draw for an extended period. Once the available energy is depleted, the voltage can drop rapidly, causing the connected device to shut down.

4. Internal Resistance:

   • High internal resistance within the battery can lead to increased heat generation during high current draws. Excessive heat may trigger protective mechanisms, causing the battery to disconnect temporarily to prevent thermal damage.

5. Temperature Effects:

   • Temperature plays a crucial role in battery performance. High current draws can elevate the battery temperature, and if it exceeds the safe operating range, the battery protection circuit may intervene to prevent overheating.

6. Battery Aging:

   • With time and usage, batteries undergo aging processes that can affect their overall performance. Aging may result in reduced capacity, increased internal resistance, and a higher likelihood of voltage drop during high current demands.

7. Cell Imbalance:

   • In multi-cell batteries, imbalances between individual cells can occur. During high current draws, these imbalances can worsen, leading to uneven discharge and triggering protective measures.

8. Faulty Battery Management System (BMS):

   • If the battery is equipped with a BMS, a malfunction in the BMS can incorrectly interpret the conditions and trigger protective actions even when not necessary.

9. Defective Cells:

   • The presence of defective cells within the battery pack can result in voltage irregularities and premature shutdown during high current draws.

10. Inadequate Wiring or Connectors:

    • Insufficient wiring or faulty connectors between the battery and the load can contribute to voltage drop and power interruption during high current events.

What is advisable

To address these issues, it’s advisable to:

• Ensure that the battery is appropriately sized for the application.
• Verify that the current draw does not exceed the battery’s specified limits.
• Monitor and manage the battery’s temperature.
• Check for signs of aging or damage.
• Inspect the battery management system for proper functioning.

If the problem persists, consulting with the battery manufacturer or a qualified technician is recommended to diagnose and address the specific issues affecting the battery’s performance.