When connecting multiple batteries in a lithium power system, there are two primary ways to wire them: series and parallel.
Each configuration changes how your system behaves. Understanding the difference is essential for building a system that meets your voltage requirements and delivers the runtime you expect.
Trying to decide between series and parallel?
Series wiring is used to increase system voltage.
In a series configuration, batteries are connected end-to-end. The positive terminal of one battery connects to the negative terminal of the next. This adds voltage together while keeping amp-hour capacity the same.
For example:
Two 12-volt, 100 amp-hour batteries in series = 24 volts, 100 amp-hours
This type of wiring is used when your system requires higher voltage, such as 24V or 48V systems. Many larger systems rely on higher voltage to support increased power demand and improved efficiency.
Parallel wiring is used to increase capacity.
In a parallel configuration, all positive terminals are connected together, and all negative terminals are connected together. This keeps voltage the same while increasing total amp-hour capacity.
For example:
Two 12-volt, 100 amp-hour batteries in parallel = 12 volts, 200 amp-hours
Parallel wiring is the most common setup for RV, marine, and off-grid systems where extending runtime is the primary goal.
A simple way to understand the difference:
Series changes voltage
Parallel changes capacity
This distinction is critical when designing your system.
Your system voltage is typically determined by your inverter and other major components. These components are designed to operate at a specific voltage, such as 12V, 24V, or 48V.
Because of that, your voltage requirement usually determines whether you need series wiring.
Once system voltage is established, capacity is added in parallel. This allows you to increase runtime without changing the operating voltage of the system.
Regardless of configuration, proper wiring is critical.
When connecting multiple batteries, it is important to:
Use consistent cable lengths
Maintain clean, secure connections
Ensure balanced current flow across the system
Uneven wiring can lead to imbalanced charging and discharging, which can reduce performance and impact long-term reliability.
Battle Born batteries are designed to support both series and parallel configurations when installed correctly.
This flexibility allows you to design systems that meet a wide range of voltage and capacity requirements, from smaller 12V setups to larger, higher-voltage systems.
Choosing between series and parallel wiring comes down to two factors:
Your system voltage requirements
Your desired energy capacity and runtime
Series wiring increases voltage to match system requirements. Parallel wiring increases capacity to extend runtime.
When both are used correctly, they allow you to build a battery system that is efficient, scalable, and aligned with your overall power needs.