Introduction
Series connection is widely used in large energy storage systems, telecom battery banks, and industrial UPS systems. However, improper series wiring can accelerate battery degradation. Understanding the impact is essential for maximizing lifespan and performance.
Keywords: series connection lead-acid battery, battery balance, OPzV battery system design, energy storage bank.
1. Voltage Imbalance: The Biggest Risk
In a series string, each battery must carry the exact same current. If one battery has slightly lower capacity, it becomes fully charged or discharged earlier, causing:
- Overcharging
- Deep discharging
- Sulfation buildup
Both conditions shorten cycle life dramatically.
2. Impact on System Performance
Voltage imbalance results in:
- Reduced usable capacity
- Higher internal resistance
- Temperature rise
- Premature failure of the weakest unit
This “weakest battery effect” is the main concern of long series strings such as 24V, 48V, or 96V systems.
3. How to Improve Series Performance
- Use same brand, model, and production date batteries.
- Keep equal cable lengths.
- Apply battery balancing chargers.
- Perform periodic capacity testing.
- Maintain identical temperature conditions.
4. When Series Connection is Ideal
Series configuration is best for:
- High-voltage inverters
- Large hybrid solar systems
- Telecom OPzS/OPzV battery banks
- Industrial DC backup systems
Conclusion
Proper management of series-connected lead-acid batteries significantly improves reliability and prevents uneven aging.
