Understanding Voltage Drops in an Inverter During Power Cuts

Your inverter jumping from a nominal 13.7 volts to 12.4 volts even under no load conditions during a power cut can be a mystery, especially with your EL 150 Exide Tubular battery and Exide 1050 VA machine. This article aims to guide you through the potential reasons behind this behavior and offer actionable recommendations.

Potential Reasons for Voltage Drops

1. Battery State of Charge (SOC) and Discharge Cycle

When batteries are discharged, their voltage naturally drops. If your battery was recently charged, a voltage drop is normal behavior. A fully charged battery typically shows a higher voltage around 13.7 volts. As the battery discharges, its voltage will gradually decrease. Therefore, if you observe a drop from 13.7 volts to 12.4 volts under no load conditions, this could be a sign of a normal discharge process.

2. Battery Age and Health

Over time, batteries lose capacity and efficiency. This is especially true when batteries are subjected to deep discharges frequently. As they age, batteries may struggle to maintain their voltage levels. Regularly check your battery's health and capacity to ensure it is performing optimally.

3. Battery Management System (BMS) and Voltage Regulation

Inverters often have built-in Battery Management Systems (BMS) that regulate the voltage output. If the BMS detects that the battery voltage is dropping below a certain threshold, it may cause the inverter to adjust its output voltage to prevent damage. Additionally, some inverters have a safety cut-off mechanism that activates when the battery voltage falls to a specific level to prevent further discharging.

4. Temperature Effects

Battery performance is significantly influenced by temperature. Cold or hot temperatures can cause voltage fluctuations. Extreme temperatures may lead to an apparent drop in voltage readings. Ensure your battery operates within the recommended temperature range to maintain optimal performance.

5. Increased Internal Resistance

As batteries age, their internal resistance increases, leading to voltage drops under load or even at rest. This can result in noticeable differences in voltage readings. Monitoring internal resistance is crucial for assessing battery health.

6. Measurement Error

Using an inaccurate multimeter can lead to incorrect voltage readings. Ensure your multimeter is properly calibrated to avoid measurement errors. Regular maintenance and calibration of your testing equipment can help ensure accurate results.

7. Inverter Behavior and Settings

Certain inverter settings can affect how voltage is reported. Review your inverter manual for any specific behaviors related to voltage display. Faulty inverter settings may not display voltage accurately, so it is important to check and adjust these settings as needed.

Recommendations

To better understand the voltage behavior of your inverter and battery system, consider the following recommendations:

Check Battery Health: Test the battery with a load tester or take it to a professional to assess its health and capacity. Monitor Conditions: Keep an eye on the voltage over time to see if the drop is a one-time event or a recurring issue. Inspect Connections: Ensure all connections between the battery and inverter are clean and secure to minimize resistance. Consult Manufacturer: If the problem persists, consult the user manual or contact Exide or the inverter manufacturer for specific troubleshooting advice.

By addressing these factors, you can gain a clearer understanding of the voltage behavior in your inverter and battery system, ensuring optimal performance and longevity.