Primary Keywords:
lead acid battery current imbalance, parallel battery imbalance, battery bank balancing
Introduction
One of the most common problems in parallel lead-acid battery systems is current imbalance. Uneven current distribution can silently shorten battery life and reduce overall system reliability. This article explains why current imbalance occurs and how to effectively prevent it.
What Is Current Imbalance?
Current imbalance happens when one battery delivers or receives more current than others in a parallel bank, often due to differences in internal resistance.
Main Causes of Imbalance
- Different Battery Ages
Older batteries have higher internal resistance, forcing newer batteries to carry more load. - Unequal Cable Resistance
Different cable lengths or cross-sections cause uneven current paths. - Temperature Differences
Batteries operating at higher temperatures discharge faster. - Manufacturing Variations
Even small differences between batteries become significant in parallel operation.
Negative Effects
- Accelerated aging of stronger batteries
- Reduced usable capacity
- Overheating and safety risks
- Frequent system alarms or failures
Practical Solutions
- Use symmetric wiring (diagonal connection method)
- Install individual battery fuses
- Measure current using clamp meters during operation
- Replace batteries as complete sets
Conclusion
Current imbalance is not immediately visible but has long-term destructive effects. Proper wiring, monitoring, and battery matching are essential for stable parallel operation.
