What’s the Difference Between Connecting Batteries in Series and Parallel?

Leisure batteries can be connected in series or parallel, depending on whether you want to increase voltage or capacity.

Batteries Connected in Parallel

Connecting batteries in parallel keeps the system voltage the same but increases the total capacity (Ah).

• Voltage: stays the same (12V system remains 12V)
• Capacity: increases

Example:

• 2 × 12V 100Ah batteries in parallel = 12V 200Ah

This is the most common setup in campervans, caravans, and motorhomes when you want more usable power.

Batteries Connected in Series

Connecting batteries in series increases the voltage, but the capacity stays the same.

• Voltage: increases
• Capacity: stays the same

Example:

• 2 × 12V 100Ah batteries in series = 24V 100Ah

Series connections are typically used in 24V or 48V electrical systems, which are less common in campervan installations.